If you go out and carefully study the sky near dusk or dawn, and you have relatively dark skies, the odds are that you should not have to wait more than 15 minutes before you see one of the more than 35,000 satellites now in orbit around Earth. 

Most of these "satellites" are actually just "space junk" ranging in size from as large as 30 feet, down to about the size of a softball.  The Joint Space Operations Center (JSpOC) headquartered at Vandenberg AFB in California, keeps a constant watch on all orbiting debris. Try our Satellite Tracker from N2Y0.com and spot the International Space Station and more!

And in fact most satellites -- especially the bits of debris -- are too faint to be seen with the unaided eye.  But depending on who's counting, several hundred can be spotted with the unaided eye.  These are the satellites that are large enough (typically more than 20 feet in length) and low enough (100 to 400 miles above Earth) to be most readily seen a sunlight reflects off them.

The biggest

The International Space Station (ISS) is by far the biggest and brightest of all the man-made objects orbiting the Earth. 

On-orbit construction of the station began in 1998, and is scheduled to be complete by 2011, with operations continuing until around 2015.  More than four times as large as the defunct Russian Mir space station, the completed International Space Station will ultimately have a mass of about 1,040,000 pounds (520 tons) and will measure 356 feet across and 290 feet long, with almost an acre of solar panels to provide electrical power to six state-of-the-art laboratories.

Presently circling the Earth at an average altitude of 216 mi (348 km) and at a speed of 17,200 mi (27,700 km) per hour, it completes 15.7 orbits per day and it can appear to move as fast as a high-flying jet airliner, sometimes taking about four to five minutes to cross the sky. Because of its size and configuration of highly reflective solar panels, the space station is now, by far, the brightest man-made object currently in orbit around the Earth. 

On favorable passes, the space station can appear as bright as the planet Venus, at magnitude -4.5, and some 16 times brighter than Sirius, the brightest star in the night sky. Some have made estimates as bright as magnitude -5 or -6 for the station (smaller numbers represent brighter objects on this astronomers scale).

And as a bonus, sunlight glinting directly off the solar panels can sometimes make the ISS appear to briefly "flare" in brilliance to as bright as magnitude -8; more than 16 times brighter than Venus! 

Other things to see

Along with the ISS, you can also look for China's Tiangong-1 space laboratory, which has hosted visiting crews on Shenzhou spacecraft in recent years. Also visible to the naked eye is the Hubble Space Telescope.

Russia's Soyuz and Progress spacecraft, as well as SPaceX's Dragon and Orbital ATK's Cygnus capsules, are much smaller than NASA's space shuttles (which were also visible to the naked eye until they were retired in 2011). But they could potential be visible under the best observing conditions.

Viewing opportunities

During the northern summer, when the nights are the shortest, the time that a satellite in a low-Earth-orbit (like the ISS) can remain illuminated by the sun can extend throughout the night - a situation that can never be attained during other times of the year. Because the ISS circles the Earth about every 90 minutes on average, this means that it's possible to see it not just on one singular pass, but for several consecutive passes. 

Moreover, because the ISS revolves around the Earth in an orbit that is inclined 51.6-degrees to the equator, there are two types of passes that are visible. 

In the first case (we'll call it a "Type I" pass), the ISS initially appears over toward the southwestern part of the sky and then sweeps over toward the northeast. 

About seven or eight hours later, it becomes possible to see a second type of pass (we'll call it "Type II"), but this time with the ISS initially appearing over toward the northwestern part of the sky and sweeping over toward the southeast. 

Type I passes will initially be visible in the morning hours, prior to sunrise. By early July, Type I passes will be visible during the evening hours, just after sunset, while Type II passes will be occurring in the early morning.  By late July, visibility of the Type II passes will have shifted into the evening hours.  

When and where to look

So what is the viewing schedule for your particular hometown? You can easily find out by visiting one of these four popular web sites:

• Chris Peat's Heavens Above
• Science@NASA‘s J-Pass
• NASA's SkyWatch
• Spaceweather.com

Each will ask for your zip code or city, and respond with a list of suggested spotting times. Predictions computed a few days ahead of time are usually accurate within a few minutes. However, they can change due to the slow decay of the space station's orbit and periodic reboosts to higher altitudes. Check frequently for updates.

Some passes are superior to others.  If the ISS is not predicted to get much higher than 20-degrees above your local horizon, odds are that it will not get much brighter than second or third magnitude (10-degrees is roughly equal to the width of your fist held at arm's length).  In addition, with such low passes, the ISS will likely be visible for only a minute or two.  Conversely, those passes that are higher in the sky – especially those above 45-degrees – will last longer and will be noticeably brighter. 

The very best viewing circumstances are those that take the ISS on a high arc across the sky about 45 to 60 minutes after sunset, or 45 to 60 minutes before sunrise. In such cases, you'll have it in your sky upwards to four or five minutes; it will likely get very bright and there will be little or no chance of it encountering the Earth's shadow.

While the ISS looks like a moving star to the unaided eye, those who have been able to train a telescope on it have actually been able to detect its T-shape as it has whizzed across their field of view.  Some have actually been able to track the ISS with their scope by moving it along the projected path.  Those who have gotten a good glimpse describe the body of the Space Station as a brilliant white, while the solar panels appear a coppery red.

For evening passes, the ISS will usually start out rather dim and then tend to grow in brightness as it moves across the sky.  In contrast, for the morning passes, the ISS will already be quite bright when it first appears and will tend to fade somewhat toward the end of its predicted pass.  This is due to the change in the angle of sunlight hitting the vehicle. 

Lastly, remember that in certain cases, the ISS will either quickly disappear when it slips into the Earth's shadow (during evening passes) or quite suddenly appear when it slips out of the Earth's shadow (during morning passes).  This becomes increasingly more likely for passes that take place more than 90 minutes after sunset or more than 90 minutes before sunrise.

Editor's note: If you have an amazing photo of the Intenrational Space Station, satellite or any other night-sky sight that you'd like to share for a possible story or image gallery, send images and comments in to managing editor Tariq Malik at spacephotos@space.com.

This article was updated on March 18, 2016 to include new details about satellite tracking widgets, and other spacecraft that may be visible from Earth to the unaided eye. Correction: This article was updated 6/20/09 to name the Joint Space Operations Center as the organization that monitors space junk.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y. Follow us@Spacedotcom, Facebook or Google+. Originally published on Space.com.

The moon is at new phase on Sept. 18 and during this upcoming week will appear as a gradually diminishing crescent of light in the after midnight-hours, and won't be much of a hindrance to stargazing.  This combined with the fact that at this particular time of the year the hazy skies of summer are giving way to clearer skies and cooler overnight temperatures means that this is an optimum week to check out the beautiful summer Milky Way. 

As soon as darkness falls, it becomes evident as a wide glowing arch of variety and beauty, stretching across the sky from the northeast to southwest. 

Sweep with binoculars from the Scorpion's tail, through the Summer Triangle, and then down to Cassiopeia and Perseus.  You'll find concentrations of stars, clusters, large apparent gaps (such as the "Great Rift" in Cygnus), and more stars than you probably thought existed.

City dwellers miss out

Unfortunately, because of the tremendous increase in light pollution over the past 35-years, the majority of our current generation has never really seen the night sky in all its grandeur.  Indeed, the Milky Way has been one of the chief victims of atmospheric pollution – by light and other factors.  In most major metropolitan areas, there is very little hope of ever seeing this broad path of light at all. 

However, a few years ago, I stumbled across an old observing logbook of mine where I noted that on the night of Aug. 30, 1976, I was able to glimpse the bright stretch of Milky Way that runs through Cygnus from of all places, the Throggs Neck section of The Bronx!  It was one of those very special evenings, so rare in the summertime, with unusually low humidity and crisp, very transparent skies. 

Sadly, I should point out, that even if the same weather pattern were to recur tonight, I wouldn't be able to repeat my 1976 observation, because the junior high school across the street from where I used to live has since installed brilliant security lighting on its roof.  In addition, nearby high-pressure sodium vapor streetlights add their own garish illumination to such a degree that the general surroundings are bathed in a sort of artificial twilight; it's now so bright that you can readily read the fine print in a newspaper in the middle of the night, if you were so inclined.

Bright enough to cast shadows

Our eyes have some detail-discerning properties that not even the best long-exposure photograph can match.  This advantage is considerable in the case of the Milky Way, which has such great extent that it does not require a telescope. I can recall with great fondness one particular night nearly 35-years ago, spent under the dark skies of upstate New York's Adirondack Mountains where I spent a considerable amount of time savoring the Milky Way in all of its magnificence. 

So clear was the sky, that rather than appearing as a filmy band of light, the Milky Way appeared granulated in texture, and glowed so bright that it actually cast faint shadows! 

I must now confess here, however, that even though I had my trusty 7 x 35 wide-angle binoculars, I hardly used them at all that night, except to pick out deep-sky objects (star clusters or nebulae) of interest.  Looking at Via Lactea (the Milky Way's Latin name) through binoculars – except to view certain highlights – is a kin to closely scrutinizing a painting with a magnifying glass, which only reveals the coarse canvas, and not the actual art itself.

The Bortle Scale

A long-time friend of mine and a well-known authority on comets, John Bortle, assiduously observes the night sky from Dutchess County, New York.  Back in 2001 he developed a nine-point scale which allows a person to judge just how dark (or bright) their local sky is. 

For the kind of sky that now exists around my old stomping grounds in The Bronx, Mr. Bortle would likely call it a "Class 9."  Specifically defined: The entire sky is brightly lit. Many stars making up familiar constellation figures are invisible, and dim constellations such as Cancer and Pisces are not seen at all. The only celestial objects that really provide pleasing telescopic views are the Moon, the planets, and a few of the brightest star clusters (if you can find them). 
People who live up to 50 miles from a large metropolitan area probably have a "Class 5" sky on the Bortle scale.  That's a sky where the Milky Way is very weak or invisible near the horizon and looks rather washed out overhead. Light sources are evident in most if not all directions. Over most or all of the sky, clouds are quite noticeably brighter than the sky itself.

People who live in a rural location, out to 75 miles or more from a major city likely have access to a "Class 3" sky: Some indication of light pollution is still evident along the horizon, but now the Milky Way appears quite noticeable and more complex.  Your telescope is vaguely apparent at a distance of 20 or 30 feet. 

But for the ultimate in skywatching, there is the "Class 1" sky . . . the kind that I enjoyed in the Adirondacks all too many of those years ago: From such a sky the Milky Way is capable of casting obvious diffuse shadows on the ground. The presence of Jupiter or Venus in the sky actually hinders your attempt to adapt to the darkness. Airglow (a very faint, naturally occurring glow most evident near to the horizon) is readily apparent. If you are observing on a grass-covered field bordered by trees, your telescope, companions, and vehicle are almost totally invisible.
Or as Mr. Bortle so eloquently put it: "This is an observer's Nirvana!" 

• Gallery: The Milky Way
• The New Tourist's Guide to the Milky Way
• Astrophotography 101

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

Then felt I like some watcher of the skies           
When a new planet swims into his ken

Thus wrote John Keats, referring to William Herschel's discovery of the planet Uranus a few years before in 1781. Measurements of the position of Uranus soon showed that it was under the gravitational influence of another planet, farther out in the solar system.

Predictions of the position of this new planet were made by John Couch Adams in 1843 and Urbain Le Verrier in 1845-1846, but both mathematicians had great difficulty in persuading any astronomer to actually look for the planet. Finally on September 23, 1846, a German astronomer, Johann Gottfried Galle, used Le Verrier's chart to actually locate and observe Neptune. This led to a major controversy as to which country should be credited with the discovery; ultimately the honor was shared.

Ironically, Galle was not the first person to observe Neptune. It was actually observed twice by Galileo in 1612 and 1613, but he mistook it for a fixed star. At the time Galileo made this observation, Neptune was in conjunction with the planet Jupiter, meaning that both planets appeared very close together in the sky.

Now it's your turn

This week, Neptune is again in conjunction with Jupiter, and with some preparation, you can spot it anytime now through next week. [Note, however, that in binoculars or small telescopes, Neptune will appear much like a star-like point of light. Only very large telescopes can make out any detail on the faraway world.]

The brightness of objects in the sky is measured by a system of magnitudes, a scale on which the brightest stars are described as 1st magnitude and the faintest stars visible to the naked eye as 6th magnitude. It is thus an inverse scale: the fainter an object, the larger its numerical magnitude. Neptune is an 8th-magnitude object, two magnitudes fainter than the faintest stars visible to the naked eye, so a small binocular or telescope is needed to make it visible.

Normally finding Neptune amongst the stars is like finding the proverbial needle in a haystack. It requires detailed star charts and a great deal of patience. However, this week Jupiter will do all the hard work for you, and will make it really easy to spot Neptune.

You will still need a binocular or small telescope to see Neptune, but the finding process will be easy.

How to find it

Look at the map accompanying this article. It shows the view on the morning of July 12, but the positions of the planets won't change a lot all week. Both planets are moving from left to right relative to Mu Capricorni, Jupiter a lot faster than Neptune. Neptune will be the only bright object (other than Mu Capricorni) just to the north of Jupiter for the next week. You can find it any night this week.

Start with Jupiter, at 3 a.m. by far the brightest object in the southern sky. Venus is brighter, but it hasn't risen yet. With a binocular or small telescope you will see Jupiter with its accompanying Galilean moons.

Sweep slightly upward in the sky, and you'll see the fifth magnitude star Mu Capricorni. Sweep a little further upward, and there will be the planet Neptune, quite a bit fainter than Mu Capricorni. Because Neptune is so far away, it will appear star-like in all but the largest telescopes, but will stand out because of its odd blue-green color, quite different than any star.

Congratulations…you have now duplicated Galileo's observations of 1612 and 1613, and have seen a planet that most amateur astronomers seldom if ever see.

• More Night Sky Features from Starry Night Education

This article was provided to SPACE.com by Starry Night Education, the leader in space science curriculum solutions.

Over the 4th of July weekend, Americans will have "spectacular views" of the International Space Station as it makes several passes over the country, NASA said Tuesday.

The space station orbits Earth every 90 minutes in a constantly changing pattern. It is brighter than any stars in the sky right now, typically visible near dawn and just after dusk, weather permitting.

It will be almost directly over head during some passes this weekend, according to a NASA statement.

The trick is knowing when and where to look. SPACE.com's Satellite Spotting Guide has full details.

Telescopes are not useful, because the station moves across the sky too quickly, appearing much like other satellites but brighter, sometimes seeming like an airplane on approach to landing. Binoculars, however, can prove useful and might allow a glimpse of some of the station's structure.

The orbiting outpost is visible because it reflects sunlight. It is 357 feet long, about the length of a football field including the end zones, and 45 feet tall. Its reflective solar arrays are 240 feet wide, a wingspan greater than that of a jumbo jet, and have a total surface area of more than 38,000 square feet.

In March, skywatcher Mike Tyrrell captured videos of the space station with its new solar wings -- which make it brighter than ever -- from his home-built observatory at the back of his garage near Manchester, England.

The International Space Station (ISS) is easy to spot with the naked eye if you know when and where to look. A new notification service on Twitter will tell you exactly when to go out and look up.

As with many data services and applications (or apps, as developers call them) these days, this one was created by a couple guys who were interested in the topic.

Dutch science reporter Govert Schilling and journalist/web developer Jaap Meijers created @twisst, a Twitter service that will tell you when the space station will fly over your location.

There are other online sites that provide spotting information. What's new is to get the notifications through Twitter, a social network site that's turning out to be much more.

The new service is in a test phase, according to a statement from Schilling. Twitter users can follow it at @twisst (twitter.com/twisst). Others can learn about it at a regular web site.

The service "basically is an app," Schilling told SPACE.com. "Twitter is such a great platform for an app like @twisst, because people can be sent information on a very personal level. And the Twitter users choose who they want to follow and what information they want to receive."

As with other satellites that are easy to spot in the evening or pre-dawn sky, the space station is visible only for a few minutes on each pass.

The orbiting outpost constantly passes over different parts of the planet as it circles Earth every 90 minutes or so. It flies at an average altitude of 216 miles (348 km) and speeds along at 17,200 mph (27,700 kph). It is about as big as a football field and has highly reflective solar panels. It's the reflection of sunlight that makes it visible from Earth.

Europe will enjoy several passes this week, Schilling said. Good passes will occur for the United States on July 7 and East Asia on July 10.

• How to Spot the ISS and Satellites
• More Skywatching Features
  

Editor's Note: This article was updated at 10::12 a.m. ET 6/27 to include a comment from Schilling about the service being an app.

With the Space Shuttle Discovery scheduled to undock from the International Space Station (ISS) on Wednesday, skywatchers across much of the United States and southern Canada are in for a real treat on Wednesday, Thursday and Friday evenings.

Should clear skies prevail, there will be opportunities to see both Discovery and the orbiting station flying across the sky from many locations.

The sight should easily be visible to anyone, even from brightly-lit cities. Already last week, skywatchers were spotting the station easily after it spread its newly deployed solar panels. Mike Tyrrell of England shot videos of the station, on multiple passes, from his garage observatory.

Other satellites too

The appearance of either the shuttle or the space station moving across the sky is not in itself unusual. On any clear evening within a couple of hours of local sunset and with no optical aid, you can usually spot several orbiting Earth satellites creeping across the sky like moving stars. Satellites become visible only when they are in sunlight and the observer is in deep twilight or darkness. This usually means shortly after dusk or before dawn.

What makes the prospective upcoming passages so interesting is that you’ll be able to see the two largest orbiting space vehicles in the sky at the same time.

Shuttle Discovery is expected to undock from the ISS at 3:53 p.m. Eastern Daylight Time on Wednesday.  Discovery will fly around the ISS before finally pulling away from the Station at 5:37 p.m. EDT, although it should still remain at a relatively close distance to it until its scheduled return to the Kennedy Space Center in Florida on Saturday, March 28.

What to expect

Both vehicles will be traveling across North America near the most northerly part of their respective orbital trajectories that is taking them directly over latitude 51.6-degrees N.

Appearing as a pair of very bright stars, the ISS should appear as the noticeably brighter object and will be leading Shuttle Discovery as they move across the sky.  

While the ISS looks like a moving star to the unaided eye, those who have been able to train a telescope on it have actually been able to detect its T-shape as it whizzed across their field of view.  Some have actually been able to track the ISS with their scope by moving it along the projected path.  Those who have gotten a good glimpse describe the body of the space station as a brilliant white, while the solar panels appear a coppery red.

Traveling in their respective orbits at approximately 18,000 mph (29,000 kilometers per hour), both should be visible from about one to four minutes (depending on the particular viewing pass) as they glide with a steady speed across the sky.

Because of its size and configuration of highly reflective solar panels, the space station is now, by far, the brightest man-made object currently in orbit around the Earth.  On favorable passes, it can appear as bright as the planet Venus at magnitude -4.5 and some 16 times brighter than Sirius, the brightest star in the night sky. 

During this current mission, astronauts have deployed the space station's final set of solar arrays and based on recent observations they have made the ISS appear even brighter; some have made estimates as bright as magnitude -5 or -6 (one and a half to 4 times brighter than Venus!). And as a bonus, sunlight glinting directly off the solar panels can sometimes make the ISS appear to briefly "flare" in brilliance.

Local sighting shedules

So what is the viewing schedule for your particular hometown? You can easily find out by visiting one of these three popular web sites:

• NASA's SkyWatch
• Science@NASA's J-Pass
• Chris Peat's Heavens Above

Each will ask for your Country, City or a zip code, and respond with a list of suggested spotting times. Predictions computed a few days ahead of time are usually accurate within a few minutes. However, they can change due to the slow decay of the space station's orbit and periodic reboosts to higher altitudes. Check frequently for updates.

Regions of visibility

Generally speaking, the shuttle-ISS tandem will be visible across southern Canada and the northern and central United States.

Locations that are situated above latitude 40-degrees north, will be able to partake in at least a few of the Wednesday/Thursday/Friday evening viewing opportunities. New York and Salt Lake City, for instance, will have three opportunities with the duo getting as high as roughly one-quarter of the way up from the horizon to the overhead point (called the zenith). 

As one heads farther north, the number of sighting opportunities increase and viewing circumstances improve. Across southern Canada, at least four and in some cases as many as five opportunities to see the shuttle and space station will occur for most cities. Indeed, for cities such as Vancouver, Calgary, Edmonton, the two space vehicles will be available twice on consecutive nights (either Wednesday-Thursday or Thursday-Friday).  And their tracks across the sky in most cases will be much higher: as high as 72-degrees from Montreal, 77-degrees for Vancouver and 84-degrees (practically overhead) for Winnipeg.     

Between roughly 35 and 40-degrees north latitude, however, the viewing options become much fewer, perhaps only one or two chances at best, with sky tracks no better than 10 or 15-degrees above the horizon.  Washington, D.C., Philadelphia and St. Louis have two chances; San Francisco, Oklahoma City and Virginia Beach get only one chance.  Meanwhile, localities below roughly latitude 35-degrees north are out of luck, with the shuttle/ISS tandem not rising higher than 10-degrees above the horizon; too low to be considered favorable for viewing. 

Other locations

For Europe, viewing circumstances will mirror the conditions for Canada and the northern United States, although Discovery and the ISS will still be docked on Wednesday evening (Greenwich Time) and will thus appear as a singular moving star, but they'll be two separate objects on Thursday and Friday.

In the Southern Hemisphere, Australia's New South Wales, Victoria and Tasmania are favored with a few passes on Thursday, Friday and Saturday, but in the early morning hours before sunrise. The same holds true for New Zealand. For much of South America the shuttle/ISS tracks are unfortunately too far to the south for good visibility, but for southernmost Chile and Argentina (Patagonia) as well as the Falkland Islands, Discovery and the ISS should be readily visible before sunrise on Thursday, Friday and Saturday. 

Again, keep in mind again that once undocked, Discovery should appear to trail the space station as they track across your sky.  On Wednesday evening, they will be separated by only about a half-degree (the apparent width of the moon).  By Friday evening, the distance between them will have widened to nearly 10-degrees; the ISS will be leading Discovery across the sky by almost a half-minute.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

A recently discovered comet is making its closest approach to Earth in the next few days and offers anyone with binoculars or a small telescope a chance to see some frozen leftovers of our solar system's making.

Comet Lulin has, as expected, crossed the threshold to naked-eye visibility for people with dark, rural skies. It hovers just inside that envelope of visibility, however, and is not likely visible from cities, where the glare of urban lights can drown out all but the brightest night-sky objects.

"The comet is now naked-eye (if you're out in the country) and is brightening every day as it approaches Earth," said Jack Newton, who has made several photographs of Lulin from his Arizona Sky Village, a residential community committed to pristine natural surroundings and dark skies. "Some feel it will reach maximum brightness on Saturday morning."

NASA has imaged the comet, too, finding that it is shedding into space enough water to fill an Olympic-size swimming pool every 15 minutes, as the sun boils the comet's surface material away.

Lulin will be closest to Earth -- about 38 million miles, or 160 times farther than the moon -- on Feb. 24 [sky map].

Challenging to find

The comet, tinted green because of the chemicals in its head, or coma, has been a delight to seasoned skywatchers like Newton, who know how to find faint objects in the sky and then zoom in on them with binoculars and telescopes.

But a comet this dim can prove challenging for the rest of us.

"For those not-so-seasoned folks, I would advise them not to expect anything awe-inspiring," said Joe Rao, SPACE.com's Night Sky Columnist. "Visually to the naked eye in a dark sky, Lulin looks like a dim, fuzzy 'star' and in a small telescope it appears like a fuzzball ... somewhat brighter and more concentrated near the center and more diffuse around the edges.  As comets go, it's nice, but casual skywatchers are more likely to say, 'That's it?' as opposed to more experienced observers who might actually utter, 'Oh, wow!'"

Comets are known for their tails, which, like the fuzzy heads, form when solar radiation breaks up surface ice and minerals. The stuff escapes into space, forming an ephemeral atmosphere that glows with reflected sunlight. Lulin has formed and lost its tail at least twice, when gusts of solar wind tore it off.

Observers last night found little or no tail.

Worth a look

Still, even a cosmic fuzzball can inspire a wee bit of awe as one goes out, looks up, and spots a frozen ball of rock and ice that's been hurtling through the solar system since its formation 4.6 billion years ago, just now making its first pass through the inner solar system.

For most locations in the Northern Hemisphere, Lulin rises soon enough to be spotted in the late evening if you know where to look. The light from objects nearer to the horizon must pass through more of Earth's atmosphere, however, so the best time to see the comet is after midnight, when it's high in the sky.

SPACE.com asked Jack Newton if he'd recommend the comet to casual observers Saturday night. "Absolutely," he said. "Binoculars should be just great."

On the night of Feb. 23, Lulin will be just 2-degrees south-southwest of the planet Saturn, which Rao said will serve as a good benchmark to locate the comet.

800 gallons of water a second

Meanwhile, NASA used its Swift Gamma-ray Explorer satellite to photograph Lulin in ultraviolet and X-rays.

"The comet is quite active," said Dennis Bodewits of NASA's Goddard Space Flight Center in Maryland. "The UVOT data show that Lulin was shedding nearly 800 gallons of water each second."

"We are looking forward to future observations of Comet Lulin, when we hope to get better X-ray data to help us determine its makeup," said Jenny Carter, at the University of Leicester, U.K., who is leading the study effort. "They will allow us to build up a more complete 3-D picture of the comet during its flight through the solar system."

The comet is headed away from the sun now, back to the dark depths of the outer solar system. It will fade from our view by mid-March.

During the next few weeks, a comet bright enough for observation in binoculars and possibly even with the naked eye will provide a fine skywatching target when weather permits.

Comet Lulin will be closest to Earth on Feb. 24 and prime viewing will occur than and on surrounding nights. For sharp-eye viewers with dark, rural, skies, the comet is expected to be visible as a dim, fuzzy star.

People living in cities and suburbs are not expected to see the comet with the naked eye, but binoculars and telescopes will reveal its cloudy head and perhaps a striking tail, too. Comets are unpredictable, however, so it's impossible to say how bright this one might become.

Already Lulin is an enjoyable target for small telescopes, producing several striking photographs in the predawn sky. The object is best found using a sky map tailored to your location.

The discovery

The comet was photographed by Chi Sheng Lin using a 16-inch telescope at the Lulin Observatory at Nantou, Taiwan on July 11, 2007.  But it was a 19-year old student, Quanzhi Ye at Sun Yat-sen University in Mainland China who first recognized the new object on three images that were taken by Lin. 

Initially it was thought to be an asteroid, new images taken a week later revealed the telltale presence of a faint coma. 

The discovery was part of the Lulin Sky Survey project to explore the various populations of small bodies in the solar system, especially objects that possibly could pose a hazard to the Earth.  As such, the comet has been christened Comet Lulin, more formally known to astronomers as Comet C/2007 N3.

This comet is the brightest since the surprising outburst of Comet Holmes more than 15 months ago and in the coming weeks will become favorably placed in the evening sky. During mid-to-late February it will probably be about magnitude 5 or 6, making it perhaps visible to the naked eye in dark, rural locations and easily observable in binoculars or small telescopes.

Unusual orbit

Brian Marsden of the Smithsonian Astrophysical Observatory has calculated that Comet Lulin passed through the perihelion point of its orbit (its closest approach to the sun) on Jan. 10, 113 million miles (182 million kilometers) from the sun.  However, while the comet is now receding from the sun, its distance from the Earth is decreasing, with a minimum of 38 million miles (61 million kilometers) on Feb. 24. 

For this reason, the comet should be at its brightest during the last week of February; then it will fade fast by mid-March.

The orbit of Comet Lulin is very nearly a parabola, according to Marsden.  It is also rather unusual since it is moving through space in a direction opposite to that of the planets at a very low inclination of just 1.6-degrees from the ecliptic.  As such, because it is moving opposite to the motion of our Earth, the comet will appear to track rather quickly against the background stars as one observes the object from one night to the next. 

In addition, over the next three weeks, the comet will appear to rise an average of about 20-minutes earlier each night. Right now, it is best seen in the predawn sky.

Rapid track

On the night of Feb. 7, for instance, Lulin will rise above the east-southeast horizon around midnight and will appear at its highest in the sky toward the south at the break of dawn.  But on the night of the 24th, when it will be passing nearest to Earth, Lulin will be visible all night, rising in the east at dusk, peaking high in the south shortly after midnight and setting in the west around sunrise.

Currently located in the constellation Libra, Comet Lulin will appear to move on a northwest trajectory, crossing over into Virgo on Feb. 11 and passing 3-degrees north of the 1st-magnitude star Spica in Virgo on Feb. 16 (for comparison, your clenched fist held at arm's length measures about 10-degrees in width). 

On the night of Feb. 23, now virtually at its peak brightness, the comet will be sitting just 2-degrees south-southwest of the planet Saturn, which you can use as a benchmark to locate the comet.  Moreover, around this time, Comet Lulin will be racing at more than 5-degrees per day -- that's roughly the equivalent of the distance between the stars Dubhe and Merak, the "Pointer Stars" of the Big Dipper; so even a few minutes of watching with a telescope should reveal the comet's slow shift relative to background field stars.

On Feb. 27, the fading comet will slip just 1-degree south of the 1st-magnitude star, Regulus in Leo.  And come the night of March 5, Lulin -- by then probably between magnitudes 6 and 7 and no longer visible without binoculars or a telescope -- will pass to within 2-degrees of the famous Beehive Star Cluster in Cancer.

Look for an Antitail

Comets are visible because radiation from the sun releases gas and dust from the comet. That material then shines with reflected sunlight, creating a cloudy head, or coma, and sometimes one or two tails.

Even when it's at its very brightest, naked-eye observers probably see Comet Lulin as resembling only a dim, fuzzy star.  In binoculars, or a small telescope the comet may resemble an apple on a stick; that is, the comet's diffuse head or coma should appear round and somewhat condensed toward its center, with perhaps a tinge of blue or green, while a narrow tail of gas extends out to the northwest. 

In addition, telescopic observers should also look for a "spike" of light, pointing in a direction opposite to the tail.  This strange effect, called an "antitail," is caused by a thin sheet of dust that is expelled by the comet but normally is visible for a brief interval when the Earth passes through the comet's orbital plane. 

But because Earth will remain in the comet's orbital plane through February and on into March, there will be an ongoing chance of catching a glimpse of the antitail as well.

• Online Sky Maps and More
• Sky Calendar & Moon Phases
• Astrophotography 101

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

With the Space Shuttle Discovery having successfully undocked from the International Space Station (ISS) early Monday morning, skywatchers across much of the United States and southern Canada are now in for a real treat on Tuesday and Wednesday mornings.

Weather permitting, there will be opportunities to see both the Discovery orbiter and the ISS independently flying across the sky from many locations.

The sight should easily be visible to anyone, even from brightly lit cities.

The appearance of either the space shuttle or the space station moving across the sky is not in itself unusual. On any clear morning within a couple of hours of local sunrise and with no optical aid, you can usually spot several orbiting Earth satellites creeping across the sky like moving stars. Satellites become visible only when they are in sunlight and the observer is in deep twilight or darkness. This usually means shortly after dusk or before dawn.

What makes the prospective upcoming passages so interesting is that you'll be able to see the two largest orbiting space vehicles in the sky at the same time.

Shuttle Discovery undocked from the station at 5:32 a.m. EST on Monday.  Discovery then flew around the ISS before finally pulling away from the station at 7:18 a.m.  The shuttle is scheduled to return to the Kennedy Space Center in Florida Wednesday, Nov. 7 at 1:02 p.m.

What to expect

On Tuesday and Wednesday mornings, both vehicles will pass across North America three times at intervals spaced at 91.6 minutes and in each case moving on southwest-to-northeast trajectories

Appearing as a pair of very "bright 'stars," the ISS should appear as the somewhat brighter object and will be trailing Discovery.  Early Monday morning, the two vehicles had just undocked as they began their series of passes over North America and were still very close together – so close that from many locations in the eastern and central United States they appeared not as separate objects, but rather as a single bright star-like object to the unaided eye. 

It will be a different story on Tuesday and Wednesday mornings, however, as the two vehicles will have separated to a distance of 26 miles (42 kilometers). 

As seen from the ground, the apparent separation distance between the two vehicles should not appear to exceed 20-degrees.  (Your clenched fist, held at arm's length will measure roughly 10 of those degrees.)  So the maximum apparent distance between the ISS and the Discovery orbiter should not exceed "two fists" as they move across the sky.

Brighter than the stars

A telescope would be needed to make out details of the sprawling station, now orbiting at 220 miles (354 kilometers) above Earth's surface. Traveling in their respective orbits at about 17,188 mph (27,661 kilometers per hour), both should be visible on each pass for a duration of about 1 to 5 minutes.

Because of its size and configuration of highly reflective solar panels, the space station is now, by far, the brightest man-made object currently in orbit around the planet.  On favorable passes, it approaches magnitude -3 in brightness, which would rival the planet Jupiter and is four times brighter than Sirius, the brightest star in the night sky. 

On future missions, additional solar arrays will be deployed, making the ISS appear even brighter. When completed in 2010, it might even rival Venus, the brightest planet.  And as a bonus, sunlight glinting directly off the solar panels can sometimes make the ISS appear to briefly flare in brilliance.  

When and where to look

The shuttle-ISS tandem will be visible across southern Canada and most of the 48 contiguous United States.  Unfortunately, neither Hawaii nor Alaska will have favorable viewing passes during this week. 

Viewing times and locations are available at these three sites:

• NASA's SkyWatch
• Chris Peat's Heavens Above

Each will ask for either your city or your latitude and longitude, and respond with a list of suggested spotting times. Predictions that have been computed a few days ahead of time will usually be quite accurate to within less than a minute. However, they can change due to the slow decay of the space station's orbit and periodic reboosts to higher altitudes, so it is wise to check frequently for updates.

• Complete Shuttle Coverage

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

If there ever was a planet that has gotten an unfair reputation for its inability to be readily observed it would have to be Mercury, known in some circles as the "elusive planet."

Often cited as the most difficult of the five brightest naked-eye planets to see, because it's the planet closest to the Sun, Mercury never strays too far from the Sun's vicinity in our sky.

Mercury is called an "inferior planet" because its orbit is nearer to the Sun than the Earth's.  Therefore, it always appears from our vantagepoint to be in the same general direction as the Sun. Thus relatively few people have set eyes on it; there is even a rumor that the great Polish astronomer, Copernicus, never saw it.  Yet it's not really hard to see.  You simply must know when and where to look, and find a clear horizon.

And during these next two weeks we will be presented with an excellent opportunity to view Mercury in the early morning dawn sky [map].

In fact, if you've been an early riser this past week, it's quite possible you might have stumbled across Mercury on your own.  Since Nov. 20, it has been rising at least 90 minutes before sunrise, which is also just about the same time that morning twilight is beginning.  If you scan low along the east-southeast horizon about 45 minutes before sunrise, Mercury has been visible as a distinctly bright, yellowish-orange "star." 

The best views of Mercury, however, are reserved for this weekend, as Mercury will be rising more than 100 minutes before the Sun.  This is even before the break of dawn, so for a short while at least, Mercury will be visible against a completely dark sky. 

Its greatest western elongation-or greatest angular distance from the Sun in the sky-will come on the morning of Nov. 25, with Mercury standing a full 20-degrees from the Sun. 

Mercury, like Venus, appears to go through phases like the Moon.  Soon after it moved into the morning sky, Mercury was just a skinny crescent.  Currently, it's appears roughly half-illuminated and the amount of its surface illuminated by the Sun will continue to increase in the days to come.  So although it will begin to turn back toward the Sun's vicinity after Nov. 25, it will brighten a bit more, which should help keep it in easy view over the next couple of weeks. 

By month's end, Mercury will have increased in brightness to magnitude -0.6. On this astronomers scale, smaller numbers represent brighter objects and negative numbers are reserved for the brightest of all. Among the stars only Canopus and Sirius are brighter.  And Mercury should still be relatively easy to find, low in the east-southeast sky about 45 minutes to an hour before sunrise.

In early December, Mercury will be joined by the planets Mars and Jupiter, resulting in an unusually tight gathering of the three planets on Dec. 10.  On Friday, Dec. 1 SPACE.com will present a viewer's guide to this planetary trio.

• Images: Exploring Mercury
• Sky Calendar & Moon Phases
• 10 Steps to Rewarding Stargazing
• Astrophotography 101
• All About Mercury

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and

The biggest and brightest manmade object orbiting Earth just got bigger and brighter.

Astronauts on board the International Space Station (ISS) unfurled a new pair of solar energy panels that sprout out of the end of a new 17.5-ton truss section, which was brought up by the space shuttle Atlantis. They are the largest solar panels ever taken to space; fully unfolded, they reach a length of 240 feet (73 meters). They are designed to double the ISS's capability to generate power from sunlight when they go online during a future shuttle mission.

The panels are made of layers of thin gold Mylar plastic, which are highly reflective [photo].

Like other satellites, the ISS shines by virtue of sunlight reflected off of its metallic skin. The station orbits approximately 213 miles (341 kilometers) above Earth.

How bright?

Before the ISS spread its new pair of gold wings, it was already the brightest of all space vehicles, at times appearing to shine with a brilliance equal to the planet Jupiter.  Now skywatchers should notice the orbiting outpost glowing with an even greater luster. 

Nobody knows exactly how much brighter it will be, but there's a good chance that it could be brighter than magnitude -3, approaching the glow of Venus, the brightest planet.  On this astronomers' scale, smaller numbers denote brighter objects, and negative numbers are reserved for the handful of the very brightest.

And the ISS will likely get even brighter.  The solar panels are only the second of four planned arrays that will be deployed between now and before the shuttle fleet is retired in the year 2010.

When to look

Skywatchers across much of North America will have opportunities to see the ISS in the coming weeks.  To the unaided eye, it appears as a large "star" with a yellowish-white tint that moves with a steady speed across the sky. 

Beginning late next week and running through the first two weeks of October, early risers will be able to look for the station in the dawn twilight if skies are clear.  Starting in mid-October, it will make passes during convenient evening hours, soon after sundown. 

To find out if the International Space Station will pass over your hometown, go to NASA's tracking page or the Heavens Above web site. Amateurs with large telescopes and some knowledge of astrophotography have in the past had success photographing the space station.

A special class of satellites, known as Iridiums, can actually appear to flare in brightness rivaling the ISS and Venus, but only for brief flashes.

• Your Amazing Images
• Starry Night Software: Plot Satellite Tracks
• Complete Coverage: The Space Station
• Complete Coverage: Shuttle Atlantis
• Your Guide to the Night Sky
• Space Shuttle Quizzes

One look at Earth's Moon is all it takes. It has been mussed up by scads of incoming celestial objects that produced lots of craters.

But our Moon has also been on the receiving end of artificial impacts over the last few decades. Moon probes and leftover rocket stages have contributed to the crater population-albeit too small to see from our planet. Robotic lunar landers from the United States and the former Soviet Union dot the Moon too.

Add in hardware castaways from human adventurers who made their way to the Moon from 1969 through 1972 as part of NASA's Apollo program, and you've got a lot of junk on the Moon.

Pinpointing old spacecraft and artificial impact craters is not only a curatorial courtesy, but also can generate important science.

That's the report from Philip Stooke, an associate professor within the department of geography at the University of Western Ontario in London, Ontario, Canada. Stooke described his lunar detective story in a paper released at the 37th Lunar and Planetary Science Conference (LPSC), held March 13-17 in Houston.

Precise locales

Starting in the 1960s, the "space race" between the Soviet Union and the United States was on full-speed. And the Moon was a place to demonstrate one-upmanship.

NASA's Ranger, Surveyor and Lunar Orbiter spacecraft set the stage for the piloted Apollo landers. For the Soviet Union, it was the robotic Luna-series that plowed into the desolate landscape, as well as soft-landed, roved around, and even shot samples back to Earth across cis-lunar space.

NASA's Lunar Reconnaissance Orbiter (LRO), to be sent moonward in 2008, will be able to spot some of this Space Age flotsam. LRO's camera system has enough resolving power for the task.

But there is uncertainty in targeting LRO's imaging hardware to scout out the precise locales of all that gear that has plopped down on the aged Moon.

Tighter coordinates

"I've devoted almost all my time in the last five years to my Atlas of Lunar Exploration, which is in the final stages now," Stooke told SPACE.com. Part of his research is focused on tracking down the whereabouts of decades-old mooncraft and identifying craters caused by human-made objects. One might think the locations would be well-charted.

But spacecraft were "lost" because they were never found initially, Stooke said. There are those craft that came to rest on the lunar surface, with their positions known to within about 6 or 12 miles (10 or 20 kilometers), figured out by tracking a spacecraft's signals during descent. 

However, if future astronauts want to do a pinpoint landing near a piece of equipment, or wheel over to examine an old lander, they'll need much tighter coordinates.

In some instances, the imagery taken by landed spacecraft from the surface is a big help.

"That is also important for establishing the geological context of surface observations. So whenever something lands...people try to locate it precisely," Stooke pointed out. "The well established method for doing this is by comparing horizon relief features-hills or crater rims-on panoramas with the same features on orbital images. If you can match them you can locate the lander precisely."

Surveying for Surveyor

This method was basically invented, Stooke explained, by Ewen Whitaker of the Lunar and Planetary Laboratory at the University of Arizona in Tucson. He used it with Surveyor 1 and subsequent Surveyor craft that set down on the Moon between 1966 and 1968.

"But it does depend on being able to match features," Stooke added. "In very flat areas there may be nothing to match." Surveyor 5 is such a case. 

"If you have only low resolution orbital images you may not be able to make a match either-that applies partly to Surveyor 5 as well, but especially to all the Soviet landers," Stooke said. "No Soviet spacecraft has ever been located precisely in this way because they didn't land in areas of good orbital photography."

Even with photos taken from the Moon's surface, questions can remain. For example, is the Soviet Luna 9 landing area on the Moon back in 1966 in mare or highland terrain? "The argument has continued since it landed," Stooke said. 

Part of the interest is purely historical.

"It would be nice to know where Luna 9 is, the first successful lander," Stooke said. "We may want to set up a register of historic sites, not to be disturbed by future missions or hardware impacts. To do that we need accurate locations."

Search for Lunokhod

One nifty exercise that's now being considered is attempting to bounce a laser beam off a lost-on-the-Moon Soviet rover: Lunokhod 1. That eight-wheel robotic lunar buggy is outfitted with laser "retroreflectors" and rolled about within the Moon's Sea of Rains for nearly a year after landing in November 1970.

Lunokhod 1 may still have value as a laser ranging target. That's if it can be located precisely.

The Soviet machinery is sitting silent at the most northerly of all landings on the Moon to date, "and would be a vital part of understanding the Moon's exact rotation for geophysical purposes," Stooke said.

However, the robot's position is uncertain by at least 3 miles (5 kilometers), and stabs at getting laser returns all failed since early in the Lunokhod 1's mission. 

"We don't know if it is still clean or oriented suitably...if not there's no hope. But if it is, we still need a good position," Stooke said.

Tantalizing target

"The recovery of Lunokhod 1 is on my wish list," said Jim Williams of the Jet Propulsion Laboratory (JPL) in Pasadena, California. He and fellow investigators are part of a Lunar Laser Ranging (LLR) data analysis group at JPL.

Williams told SPACE.com that there are four laser retroreflector arrays on the Moon that get ranged: the Apollo 11, 14, and 15 sites plus the other Russian moonbuggy, Lunokhod 2. "As a result of the ranging, we know those positions to better than one-meter accuracy" or roughly three feet, he said.

The arrays of 14 prisms on Lunokhods 1 and 2 were built by the French. The Lunokhod 2 retroreflector has been ranged, so the design works, Williams noted. The Lunokhod would rove during daylight, but was parked at night so that the array was oriented properly for Earth-to-Moon laser ranging.  

Lunokhod 1 is a tantalizing target, Williams said.

"A few laser observations were reported early in the mobile Lunokhod 1's journey and later after it stopped moving, but those observations have never been publicly distributed or processed with a data analysis program of modern accuracy," Williams explained. "It is unclear whether the effectiveness of the Lunokhod 1 array has been compromised or whether position uncertainty and weak signal conspired to prevent its acquisition by standard ranging stations...but a modern search is in order."

Apache Point Observatory

The sole U.S. LLR station in the early 1970s tried to range Lunokhod 1, Williams said, but did not find it. 

"The task is more difficult than it sounds," Williams said. "The return signal should be very weak and only a limited spread of distance and angle could be searched...for a sequence of shots. The position may have been too poor or the Lunokhod 1 retroreflector may be obscured somehow."

There is a new LLR station now undergoing checkout at Apache Point Observatory in New Mexico.

"Once the new station is operational and returning data, then a Lunokhod 1 search will be practical," Williams said. This new equipment at the facility will be a good instrument for the search, he added, but will still require a major effort.

Location uncertainties

Meanwhile, Stooke is on the lunar lookout trail.

Early Apollo Moon landing craft and the moonwalkers themselves scuffed up areas of the lunar surface. These disturbances are visible in orbital imagery taken by later Apollo missions.

A number of discarded Apollo rocket stages and lunar module ascent stages were tracked to narrow the search area. So those which fell in areas subsequently imaged were identified fairly easily, Stooke reported in his LPSC paper.

Ranger 6's impact area may now have been found in Clementine images taken by that U.S. Defense Department Moon-orbiting spacecraft in 1994, Stooke stated. On the other hand, many impact craters made by orbiters at the end of their missions-or by failed landers-will be difficult to find because of location uncertainties.

NASA Lunar Orbiter impact sites, for example, are uncertain by hundreds of kilometers and would be very difficult to distinguish from natural fresh impacts.

On the other hand, craters formed by camera-carrying Ranger probes were found easily because images taken during their plunge toward the lunar terrain allowed impact sites to be predicted. Two of the three successful kamikaze-like Ranger missions imaged their impact points for comparison with later images.

Hiten, a Japanese lunar orbiter, should be located easily using Earth-based tracking data and observation of the impact, Stooke said.

Protection of sites

In his lunar work, Stooke noted that several challenges remain.

Can the site of Russia's Luna 2 impact be located? If it is, will visual observers be vindicated after years of doubt? Can Luna 9 or Surveyor 5 be located at last? Can the craters caused by the hits of spent rocket stages from the Apollo 15, 16 and 17 missions be found?

"The scientific value of this work includes placing lander data in better context, refining seismic results from Apollo [rocket stage] impacts, or planning future visits to old sites for study of old hardware, as Apollo 12 did for Surveyor 3," Stooke says. "If in the future it is decided to confer special designations or protection on these sites, finding them is essential."

This article is part of SPACE.com's weekly Mystery Monday series.

• Lunar Reconnaissance Orbiter
• Top 10 Apollo Era Moon Discoveries
• Moon Holds Earth's Ancient Secrets
• Apollo Moon Rocks: Dirty Little Secrets
• Skywatcher's Guide to the Moon

When the Stardust sample return capsule nose dives back to Earth in January, it will become the fastest human-made object to streak through the atmosphere. Scientists and engineers are at the ready to observe the spectacular sky show-and savvy skywatchers can join in on the aerial action too.

If all goes to plan, Stardust will release its sample return capsule carrying comet and interstellar dust particles on Jan. 15 at 12:57 a.m. Eastern Standard Time (EST). Four hours later, the capsule will enter Earth's atmosphere, zooming toward Utah and a parachute landing at roughly 5:12 a.m. EST.

During its plummet into Utah, the heat-thwarting capsule will skyrocket across the Western United States [map].

According to Stardust officials, the fireball should be visible from San Francisco perhaps up to and beyond Portland, shooting over Nevada toward its Utah landing. The artificial meteor is expected to peak in brightness as it penetrates deeper in the Earth's atmosphere, lighting up to roughly the brilliance of Venus for about 90 seconds. That brightness is expected to peak over Carlin, Nevada.

So if you live in Northern California, Oregon, Washington, Northern Nevada, Southern Idaho or Western Utah you should be able to see some part of Stardust sky show. The closer you live to the trajectory, which runs from Crescent City, California and then through Winnemucca and Elko Nevada, and finally to Western Utah, the higher the fireworks in the early morning sky will be.

Speed record

The velocity of Stardust's sample return capsule as it slices through the Earth's atmosphere is a hasty 28,860 mph (12.9 kilometers per second). At that speed, the capsule surpasses the record set in May 1969 during the return of the Apollo 10 command module, the highest speed ever attained by human beings: 24,861 mph (11.11 kilometers per second).

Even at that rate, it still doesn't beat the heat seen by the Galileo probe as it plunged into Jupiter's atmosphere on Dec. 7, 1995. The small craft reached a blistering 106,000 mph (47.4 kilometers per second).

But nobody was on the scene to get an eyeful.

Stardust's sample return capsule is a lightweight. It tips the scale at 101-pounds (46 kilograms).

In 2004, Genesis-a sister mission of Stardust-made a similar return, jettisoning a sample return capsule four-times the mass of Stardust.

Due to improperly placed sensors on the Genesis capsule, however, its parachute system failed to deploy. That resulted in a precisely placed, but busted-up capsule when the vessel hit the desert landscape at high speed. Despite the hard-landing, researchers remain hopeful they can extract meaningful science from the returned specimens of solar wind.

Science friction

Four hours after release from the main Stardust spacecraft, the sample return capsule will enter Earth's atmosphere at 410,000 feet (125 kilometers) over the Pacific Ocean.

At this point, the capsule is about 551 miles (886 kilometers) from its landing zone in Utah, and on its way to claim the record of the fastest human-made object ever to enter Earth's atmosphere.

By entry plus 38 seconds, the capsule will have already covered half the horizontal distance to its landing zone. At this point, friction from the entry is to raise the capsule's heat shield temperature, making it observable via infrared tracking equipment.

At entry plus 52 seconds, at an altitude of 200,000 feet (61 kilometers), the capsule will experience peak heating: the heat shield's exterior will spike at 365 degrees Fahrenheit (185 Celsius). Ten seconds later, peak deceleration will occur as the rapidly slowing capsule experiences 38'gs-or 38 times the force of gravity.

Airborne campaign

After nearly seven years of cruising through space, and surviving its high-speed fall, the Stardust capsule will be on a heading that leads to the U.S. Air Force Utah Test and Training Range (UTTR), southwest of Salt Lake City. Spacecraft navigators are looking to plop the capsule into an ellipse 47 by 27 miles (76 by 44 kilometers) within the UTTR.

Scientists are anxious to scrutinize the fiery fall of the capsule. Data collected is expected to help understand how natural material incoming from space is altered as it enters Earth's atmosphere. This information would be helpful in piecing together a story on chemical changes in compounds during that process-a puzzle piece for astrobiologists that study the origin of life.

A crew of researchers flying on a heavily-instrumented NASA DC-8 aircraft will study the small, speeding Stardust capsule returning from space. They face a daunting task of tracking and observing the capsule as it hurtles through the atmosphere and slows before parachuting into a Utah desert landing zone.

Public invite

The airborne campaign is coming together, with the DC-8 arriving on Jan. 3 at NASA's Ames Research Center in Silicon Valley. Once there, it will be loaded with science gear. A Jan. 11 first test flight is also on the books. 

"We have now turned our attention on setting up ground-based observations as well, including involving the public in documenting the reentry," said Peter Jenniskens, principal investigator of the Stardust Sample Return Capsule Re-entry Observing Campaign. He is a meteor astronomer at the SETI Institute in Mountain View, California.

"Some observations can only be done from the ground, such as listen for the sonic boom and observing the hot air trail in the wake of the sample return capsule drift in front of the Moon," Jenniskens told SPACE.com.

"Also, we'd like to involve the public in taking images and video of the reentry because the view from each location will be a little different, depending on how the capsule itself shields the light coming from the front," Jenniskens said.

Viewing tips

Jenniskens and his research colleagues involved in tracking the Stardust capsule offer several viewing tips

The capsule will approach the landing zone from a westerly direction. The best opportunities for viewing the entry will be along Highway 80 between Carlin, Nevada and Elko, Nevada, and further east to the Utah border, where the capsule's front side can be observed before it passes over the observer on the ground.

The peak brightness will decrease further from Carlin, lessening to about the brightness of Venus when seen from Boise, Idaho, and Salt Lake City. Observers using the naked eye will likely see the capsule as a very bright pinpoint of pink-white light.

For certain viewing locations just north of the trajectory line, the capsule will appear to pass by the Moon-above it, or below it, depending on the viewer's location.

Video, photos welcomed

By choosing their positions carefully, some observers will be able to see the capsule pass in front of the Moon. As seen by the naked eye, the capsule will disappear in the glare of moonlight, but by looking through telescopes, observers may see a tiny dot, perhaps trailed by a dark wake of dissipating heat shield material and hot air.

Moving at many times the speed of sound, the capsule will take only two to three video frames to appear to pass by the Moon.

The trail may form a thin line behind the capsule, especially near the point of peak brightness where atmospheric friction and dissipation of heat is most intense.

If you would like to become part of the observation campaign, Jenniskens noted, you can help study the reentry by contributing photos or video to NASA.

If you'd like to take part in watching the Stardust capsule's history-making dive into the record books, check out NASA's viewing forum.

• Quarry in Tow, Stardust Begins Long Journey Home
• Stardust Captures the Best Comet Image Ever
• Aerogel: Stardust's 'Butterfly Net'

This weekend Mars will make its closest approach to Earth until June 2018. While the event won't make Mars seem any bigger or brighter than the night before or after, it is among the best chances in a lifetime to view the planet.

After brilliant Venus sets, Mars is the brightest "star" in the evening sky [map].  It comes up around a quarter-hour after sunset, but give it at least two more hours to climb above the poor seeing near the horizon. By then it will be at an altitude of around 20 degrees as seen from mid-northern latitudes. 

Your clinched fist held at arm's length is roughly equal to 10 degrees, so two hours after it rises, Mars will be about "two-fists" up from the east-northeast horizon. 

Stay up late!

Mars appears much sharper and steadier when it crosses the southern meridian, soon after local midnight.  Its altitude is then about 66 degrees (more than "six fists" up from the southern horizon). 

Mars comes closest to the Earth Saturday night (around 11:25 p.m. Eastern daylight time).  The planet is then 43,137,071 miles (69,422,386 kilometers) from Earth, measured center to center.  It is at opposition nine days later, on Nov. 7.  

The red planet, usually appearing more orange to us, gleams at magnitude -2.3 and through Nov. 29 will rank as the second brightest planet, outshining even Jupiter.  (On this astronomers scale, smaller numbers represent brighter objects; negative numbers are reserved for the brightest.)

Dust off your telescope

Anyone who has a telescope, no matter how modest it may be, will surely want to see what it can do with Mars. Telescopic observers everywhere will be spying out Mars' bright polar areas, dark surface markings, white clouds and yellow dust storms.

On the night of Mars' closest approach, a telescope magnifying 90 power will make the planet seem to be the same angular size, as the full Moon would appear with the unaided eye.  Seeing the largest dark markings should be fairly easy, but finer details are notoriously difficult.

During November Mars departs Earth's vicinity as rapidly as it arrived. 

But wait, there's more ...

Between Nov. 7 and Nov. 30, it loses nearly half its brightness, diminishing from magnitude -2.3 to -1.6. 

But at the same time, Mars will be very well placed for convenient viewing.  Unlike earlier in the fall, you won't have to get up in the early morning hours to see it high in the sky.  Mars will be due south at around midnight near the time of its opposition, and around 9:45 p.m. local standard time at the end of November.

On Nov. 14, Mars will be situated below and to the left of the Moon, just one night before it turns full.

• Mars: A History of False Impressions
• Mars Madness: Viewer's Guide and Multimedia
• Mars Hoax Circulates the Internet

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

In early July, NASA's Deep Impact spacecraft will deploy a tiny impactor to smash into the nucleus of a small comet. The idea is to excavate a sizable crater and provide valuable insight into the true nature of comets.

For skywatchers here on Earth, it should also produce a large cloud of ejected material that should cause the comet to significantly brighten enough to become visible with binoculars and perhaps even with the unaided eye.

The comet that has been chosen for the task was discovered in the mid-19th century. Known as Comet Tempel 1, it already has a rather checkered history. Soon, however, it will go down in history books.

Finding the target

During June, Comet Tempel 1 will be gliding on a south-southeast course through the constellation of Virgo, the Virgin. The comet will have already made its closest approach to the Earth in early May at a distance of 66 million miles (106 million kilometers).

Although it is now moving away from the Earth, the comet is still approaching the Sun, so its overall brightness in the coming days and weeks will appear to change very little, if at all. The comet is expected to hover at around tenth-magnitude, meaning that it will glow about 40 times dimmer than a star that is at the threshold of visibility with the unaided eye.

So, to successfully locate it, you will need three things:

• A star chart with the comet's projected path plotted on it.
• A good telescope and of course,
• A dark, unpolluted night sky.

The night of impact

The Deep Impact spacecraft is expected to arrive near Comet Tempel 1 on July 4, one day before the comet reaches perihelion (its closest point to the Sun). It will have released its copper impactor about 24 hours before, while making a "deflection maneuver" to move off to a safe distance of about 300 miles (500 kilometers) from the comet.

The table-sized, 820-pound (372-kilogram) impactor is scheduled to smash into the comet's nucleus at 23,000 mph (37,000 kilometers) per hour, creating a crater perhaps 670 feet (200 meters) wide and 50 meters deep, at around 6 hours Universal Time on July 4. That time corresponds to the late evening hours of July 3 for the west coasts of the United States and Mexico.

Along the west coast of Canada, the Sun will either be setting, or it will be twilight. Dusk will also be falling for Hawaii and New Zealand. As the Earth rotates over the next 24 hours, the rest of the world will be turned toward a view (weather permitting) of the comet.

At the moment of impact, Comet Tempel 1 will be situated about 3? degrees to the east-northeast of the bluish first-magnitude star, Spica. For comparison, your fist on an outstretched arm covers about 10 degrees of sky.

So what will we see? That's the $64,000 question. Nobody can really say for sure.

Guestimates

The best consensus from comet experts suggest that after the impactor hits and the resultant dust cloud gradually expands, Comet Tempel 1 could perhaps brighten up to 6th magnitude. The faintest star that most eyes will see under dark sky conditions is 6th magnitude, so there is a chance that Comet Tempel 1 might just become bright enough to glimpse without any optical aid, but most likely that would be the case only for experienced observers in perfect conditions away from all light pollution.

Another uncertainty is just how long any enhanced brightness will last. Comets that break apart into several fragments tend to remain anomalously bright for many weeks, months, even years. On the other hand, local outbursts that occur on a nucleus that remains pretty much intact might only last for only several days.

A classic example of this took place in May 1973 when Comet Tuttle-Giacobini-Kresak unexpectedly increased in brightness nearly 10,000-fold over just a week's time. It then rapidly faded away, only to suddenly brighten-up again for a couple of days in July 1973.

At best, Comet Tempel 1 might become 15 to 40 times brighter in the hours immediately after the impact; in less than 24-hours it might go from being a dim tenth magnitude telescopic object to an easy binocular object. And perhaps it might even become just bright enough to be glimpsed with the unaided eye at a dark sky site. Just locate Spica and then, scan the region of sky to its left (east) with binoculars. If you see something that looks like a small fuzzy star or diffuse spot of light, you're probably looking at Comet Tempel 1!

Elizabeth Warner, director of the University of Maryland Observatory is serving as the liaison to amateur astronomers for the Deep Impact mission. "The coolest thing for me," she notes, "will be to observe the comet over several weeks and then hopefully (weather-permitting) see it on July 4 a bit brighter than on the previous nights and know that we made it brighter."

An Amateur Observers' Program (AOP) has been established for amateur observers as guide to observing the comet en route to, during and after the July 4 impact. Helpful information is posted at the AOP Web site at www.deepimpact.umd.edu/amateur. The site is set up so that even astronomy neophytes can get out and observe Comet Tempel 1.

(Almost) prophetic words

Nearly four decades ago, in 1967, astronomer Robert S. Richardson (1902-1981) put forward an idea about a possible comet mission which somewhat sounds today like Deep Impact. The chief purpose of Richardson's hypothetical mission was to "stimulate" a comet - causing the expelled cometary material to " . . . become a powerful source of artificially created photon emissions" (making it appear brighter).

But instead of using a projectile, Richardson suggested sending a probe carrying a nuclear weapon that could be detonated on command at the proper time. He also mused on public reaction to a possible bomb-comet experiment:

"Some people think we ought to give it a try. Others are shocked at the idea of blowing up an innocent little comet that never did any harm to anyone. Converting a periodic comet (like Encke) into a mass of bomb plasma seems to them as bad as shooting a faithful old horse and selling it to a glue factory."

On that scale, comparatively speaking, the worst that will happen to Comet Tempel 1 on the Fourth of July is that we'll give it a black eye.

• Deep Impact Special Report

Pluto is a difficult planet to find, but with a good-sized backyard telescope, it is possible. The challenge highlights the difficulty professional astronomers faced many decades ago when trying to find the elusive world in the first place.

This year marks the 75th anniversary of the discovery of Pluto. Clyde Tombaugh
discovered the ninth planet in the solar system on the afternoon of Feb. 18, 1930 while he meticulously examined a pair of photographic plates he had exposed in January at Lowell Observatory. The official announcement was made on March 13.

Tombaugh exposed the photographs on the nights of Jan. 23 and 29 using the Observatory's 13-inch Abbott Lawrence Lowell Telescope. Then, as part of the carefully planned and executed planet search, Tombaugh "blinked" the two exposures using a machine called a comparator, looking for motion of objects captured on film.

"One need only visit Lowell Observatory and view copies of the discovery images through the same eyepiece used by Clyde Tombaugh to appreciate what a remarkable discovery this was," notes Lowell's Director, Bob Millis. "The images are extremely faint and testify to the skill, concentration, and dedication that Clyde Tombaugh brought to his work."

This most renegade of all the planets has been an odd, mysterious world ever since. It will remain so for at least another decade, until the yet to be launched New Horizons Pluto-Kuiper Belt Mission arrives at Pluto, the last planet in our solar system to be visited by a spacecraft.

New Horizons is scheduled to launch in January 2006, and is due to swing past Jupiter for a gravity boost and scientific studies in February 2007, before finally reaching Pluto and its moon, Charon, in July 2015.

There is little comfort in knowing, however, that close-up images of Pluto might already have been in hand, had one of NASA's original "Grand Tours" of the outer planets had been carried out back in the 1970s. Nevertheless, astronomers have been inexorably closing in on the secrets of what to most of us is still little more than a star like speck in the sky - piecing together hints gathered from the other remote worlds by the Voyager probes.

Pluto is being observed by growing numbers of nonprofessional astronomers as well.

From the backyard

Up until about 25 or 30 years ago, any amateur who had the equipment to spot this speck against the starry background enjoyed a sort of special status among their peers. But today, thanks to the "Dobsonian revolution" - those large aperture telescopes that first appeared on the market back in the early 1980s - Pluto is being glimpsed by increasing numbers of people.

We are actually quite fortunate to be living around the time when Pluto is near the perihelion point in its orbit, or the point closest to the Sun. For Pluto, this occurs once every 2? centuries. It reached this point back in September 1989, but the planet's current brightness of magnitude 14.0 is still significantly above average, and it's destined to rise slightly to 13.8 when it arrives at opposition to the Sun on June 14. On this astronomers' scale, higher numbers represent dimmer objects, with magnitude 6.5 being about the dimmest visible to the naked eye under perfect conditions.

This is very nearly as bright as Pluto ever gets. Those who have access to at least an eight-inch or (preferably) larger telescope with high magnification and are blessed with dark, transparent skies and steady seeing have a chance of catching a glimpse of it.

Currently, Pluto is located within the constellation of Serpens Cauda. The map near the top-right of this page serves as a guide to those who choose to join the hunt.

Odd orbit

What really makes Pluto most renegade is its eccentric orbit.

From 1979 to 1999, this path brought Pluto even closer to the Sun than Neptune. Pluto's orbit is also tilted more than 17? to the plane of Earth's orbit. The two-dimensional orbit diagrams usually published in most astronomy books give a false impression that Pluto intersects Neptune's orbit. But Pluto is presently well "above" Neptune's orbit, and the paths of these two planets don't really intersect at all.

What we usually see are curtate orbits - true orbits that are projected onto the plane of the solar system. The orbital inclinations of the other eight planets are small enough to show little distortion between the actual orbits and the curate versions. Not so, however, with Pluto.

To get a really good three-dimensional conception of Pluto's orbit, as well as of the other planets and comets and asteroids, I highly recommend obtaining a sophisticated computer program like Starry Night Pro [a product of SPACE.com's parent company, Imaginova] that will not only shows such information graphically, but allows you to view motion and changing perspective.

The old days

Lowell Observatory's search for a ninth planet was begun by founder Percival Lowell in 1905. While Dr. Lowell did not live to see the discovery of Pluto, the Observatory made the official announcement of the discovery on Percival Lowell's birth date, March 13, 1930. The privilege of naming the newly discovered object presumably belonged to Lowell Observatory (located in Flagstaff, Arizona).

Clyde Tombaugh, the person who first spied Pluto on photographic plates urged the director of the observatory, V.M. Slipher to suggest a name before someone else did. Soon suggestions indeed poured in from all quarters: Cronus, Odin, Persephone, Erebos, Atlas, Prometheus . . . the list seemed endless. One young couple even wrote to Tombaugh asking that the planet be named after their newborn child!

But it was an 11-year old English girl by the name of Venetia Burney who first suggested Pluto to her grandfather, who was a professor of astronomy at Oxford. The name of Pluto was highly favored by Slipher who made the official announcement on May 1, 1930 giving full credit to little Venetia. In addition, Slipher suggested interlocking the letters P and L as the official symbol for Pluto. Not only do they stand for the first two letters of the planet, but they're also the initials of Percival Lowell.

Several Lowell Observatory astronomers continue to study Pluto, particularly Marc Buie and Will Grundy who have studied the cold, dark outer regions of the solar system - with a
special interest in Pluto - since the early 1980s. Their observations include a long-term project to monitor Pluto's brightness changes on a decade, or longer, time scales. Another project is aimed at producing a new generation of Pluto maps based on images taken with the Hubble Space Telescope.

Way out there

Pluto is currently located at a distance of roughly 2.87 billion miles from both the Earth and the Sun. It appears to be rotating on its axis once every 6.39 days and has a mass estimated to be just 0.0022 that of the Earth. In 1988, an extremely thin atmosphere was detected around Pluto. We know that its surface pressure is about 100,000 times smaller than that on Earth but still large enough for us to expect weather, winds, haze, chemistry, and an ionosphere.

At the same time, Pluto's weak gravity does not hold the atmosphere very tightly, and its upper portions may resemble the atmosphere of a comet

Finally, a rather interesting astronomical issue has surfaced in recent years as to whether Pluto should legitimately be included in the roster of nine major planets. It's decidedly small size (1,413 miles, or 2,274 kilometers across) makes it considerably smaller than any other planet, even smaller than several planetary satellites (including our own Moon). In addition, it has a moon (Charon) that is more than half its size (728 miles, or 1,172 kilometers), as well as a most unplanetary, asteroid like orbit. For some time people have suggested that Pluto is really an escaped satellite of Neptune, one that closely resembles its largest satellite, Triton.

Other's have proposed that Pluto should not be considered a planet, but rather as the "King of the Kuiper Belt Objects."

The Kuiper Belt is a ring of icy objects strung like a dirty diamond necklace in the vastness of space beyond Neptune. Kuiper Belt Objects are very faint, and extremely hard to study from the Earth. Most of the detected "KBOs" are small, with diameters typically around 62 miles (100 kilometers). The first KBOs were discovered only in 1992, but already the Kuiper Belt is changing the way we think about the outer solar system and the formation of the outer planets and comets. Pluto might be the largest of these strange bodies: some sort of condensed clumping of icy cometary nuclei.

In fact, after visiting this "neither fish nor fowl" planet, the New Horizons Pluto-Kuiper Belt spacecraft is scheduled to head deep into the Kuiper Belt to spend several years studying one or more of the icy mini-worlds in that vast region. All this begins happening a decade from now. Until then, Pluto remains an enigma.

Basic Sky Guides

• Full Moon Fever
• Astrophotography 101
• Sky Calendar & Moon Phases
• 10 Steps to Rewarding Stargazing
• Understanding the Ecliptic and the Zodiac
• False Dawn: All about the Zodiacal Light
• Reading Weather in the Sun, Moon and Stars
• How and Why the Night Sky Changes with the Seasons
• Night Sky Main Page: More Skywatching News & Features

Starry Night software brings the universe to your desktop. Map the sky from your location, or just sit back and let the cosmos come to you.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

NEW: See Video of Asteroid Toutatis' Flyby

The largest asteroid ever known to pass near Earth is making a close celestial brush with the planet this week in an event that professional and backyard astronomers are watching closely.

The space rock, named Toutatis, will not hit Earth, despite rumors of possible doom that have circulated the Internet for months. Humanity is very fortunate there won't be an impact, as the asteroid is large enough to cause global devastation.Toutatis is about 2.9 miles long and 1.5 miles wide (4.6 by 2.4 kilometers).

On Wednesday, Sept. 29 it will be within a million miles of Earth, or about four times the distance to the Moon.

No space rock this big will pass so close in the next century, scientists say. And while similarly large asteroids have hit the planet in the distant past, none so big have come so close since astronomers have had the means to notice them. Many smaller space rocks have been spotted much closer, even inside the orbit of the Moon.

NASA scientists and other asteroid experts have been watching Toutatis for more than a decade, and though its orbit changes slightly with each 4-year trip around the Sun, they have a good handle on the path.

The position of the asteroid on this pass is known to a precision roughly equal to the rock's size, said Alan Harris, a senior research scientist at the Space Science Institute. That leaves a little wiggle room for its exact location at closest approach, but not much.

"Because of the nature of the orbit, we cannot predict thousands of years into the future for this object, but in anyone's lifetime now, there is no chance" of an impact, Harris told SPACE.com.

Spotting Toutatis

Toutatis will not be visible to the unaided eye. Experienced telescope users can see it now from the Southern Hemisphere, and in early October it will be visible from the north.

Finding Toutatis will be challenging, Harris said, due to a combination of the asteroid's position in the sky and interfering moonlight.

Because the asteroid is so close, its location in the sky will vary significantly for skywatchers in different places on Earth at any given moment. And because it moves quickly, the location changes constantly. Printed sky maps struggle to provide enough detail to be useful.

"In a large telescope the motion would be perceptible against any stars in the field more or less in real time, sort of like watching the second hand on a clock," Harris said, adding that the movement would be "not quite that fast, but noticeable."

Highly experienced observers will use complex plotting information known as ephemeris data. Others can use software programs that generate maps for specific times and locations.

When, where and how

At its closest on Sept. 29, Toutatis will be visible only to observers in the Southern Hemisphere.

Large and steady binoculars will be able to pick out the pinprick of sunlight reflecting off the asteroid, providing observers "use a good program like Starry Night Pro to plot its incredibly rapid motion across the sky," said Clay Sherrod of the Arkansas Sky Observatory. (The software company Starry Night is owned by Imaginova, parent also of SPACE.com.)

Soon thereafter, experienced backyard astronomers north of the equator will have a chance to find Toutatis.

"By early October, it will suddenly be re-emerging into northern skies as its apparent trajectory will bring it back into very favorable view," Sherrod said in an e-mail interview. But by then the asteroid will be moving away from Earth and getting dimmer. It will quickly become "very difficult" to spot even with an 8-inch telescope, he said.

Sherrod photographed the giant space rock last week (it was visible then in the north through large telescopes) and said exposures longer than eight seconds showed a trail as the giant rock moved slightly against the background of stars.

"It has been quite a wonderful show so far," he said.

Strange rock indeed

Asteroid Toutatis was discovered in 1989. Scientists have modeled its strange rotation and odd shape -- it looks something like a pockmarked dumbbell -- on previous flybys.

Instead of a fixed north pole, Toutatis' axis of rotation wanders in two separate cycles of 5.4 and 7.3 Earth-days. So while most asteroids rotate somewhat like a football thrown in a perfect spiral, "Toutatis tumbles like a flubbed pass," says Scott Hudson of Washington State University.

Astronomers will use this week's flyby to examine Toutatis in greater detail, with a goal of pinning down the rock's rate of spin and better estimating its future path.

While some rumors have suggested the asteroid's forecasted course might be off by enough to cause a collision with Earth, Sherrod agrees with Harris and other scientists that there is no chance for calamity. Sherrod has been monitoring Toutatis' movement since July 3, logging more than 500 observations that allow mapping of a precise trajectory.

"Although the actual path of it has indeed varied a slight bit from the original calculated, there is absolutely no chance of a physical encounter or impact with Earth," he said.

• Mysteries of Toutatis
• Video of Toutatis Tumbling
• Starry Night Software: Map Toutatis from your location
• Ephemeris information for experienced observers from NASA

Starry Night software brings the universe to your desktop. Map the sky from your location, or just sit back and let the cosmos come to you.