The night sky tonight and on any clear night offers an ever-changing display of fascinating objects you can see, from stars and constellations to bright planets, often the moon, and sometimes special events like meteor showers. Observing the night sky can be done with no special equipment, although a sky map can be very useful, and a good beginner telescope or binoculars will enhance some experiences and bring some otherwise invisible objects into view. Below, find out what’s up in the night sky tonight (Planets Visible Now, Moon Phases, Observing Highlights This Month) plus other resources (Skywatching Terms, Night Sky Observing Tips and Further Reading).
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Monthly skywatching information is provided to SPACE.com by Geoff Gaherty of Starry Night Education, the leader in space science curriculum solutions. Follow Starry Night on Twitter @StarryNightEdu.
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Resources:
Sky Events October 2013
Moon Phases
Friday, Oct. 4, 8:34 p.m. EDT
New Moon
The moon is not visible on the date of New Moon because it is too close to the sun, but can be seen low in the east as a narrow crescent a morning or two before, just before sunrise. It is visible low in the west an evening or two after New Moon.
Friday, Oct. 11, 7:02 p.m. EDT
First Quarter Moon
The First Quarter Moon rises around 2:00 p.m. and sets around 12:30 a.m. It dominates the evening sky.
Friday, Oct. 18, 7:38 p.m. EDT
Full Moon
This is the first Full Moon following the Harvest Moon last month, and so is known as the Hunter’s Moon. It rises around sunset and sets around sunrise, the only night in the month when the Moon is in the sky all night long. The rest of the month, the Moon spends at least some time in the daytime sky.
Saturday, Oct. 26, 7:40 p.m. EDT
Last Quarter Moon
The Last Quarter Moon rises around 11:30 p.m. and sets around 2:00 p.m. It is most easily seen just after sunrise in the southern sky.
Observing Highlights
Thursday–Thursday, Oct. 3–17, before morning twilight
Zodiacal Light
This faint light reflected from countless pieces of interplanetary material will be visible in dark skies for the next two weeks. It rises in a conical shape along the ecliptic before morning twilight.
Thursday, Oct. 3, 10 a.m. EDT
Uranus at opposition
The planet Uranus will be in opposition to the sun, and visible all night.
Sunday, Oct. 6, evening twilight
Saturn, Mercury, and the Moon
A triple conjunction low in the southwest just after sunset.
Wednesday, Oct. 9, evening twilight
Mercury at greatest elongation east
Mercury will be at its greatest elongation east of the setting Sun, but this will be an unfavorable opposition because of the low angle of the ecliptic to the horizon. Saturn will be 5 degrees above Mercury.
Friday/Saturday, Oct. 11/12, 12:32–1:37 a.m. EDT
Triple Shadow Transit on Jupiter
It is very rare that three of Jupiter’s moons cast their shadows on Jupiter simultaneously. This will be visible tonight in telescopes with at least 90 mm. aperture.Later, the moons themselves will transit Jupiter’s disk. Some events will happen before Jupiter rises in your location (around midnight). This event is only visible in its entirety in eastern North America, taking place before Jupiter rises on the West Coast.
Saturday, Oct. 12, 10 p.m. EDT
Juno and the Moon
The 9th magnitude asteroid Juno will be just north of the 9-day-old gibbous moon, and close to the two wide double stars in western Capricornus, Algedi and Dabih.
Tuesday, Oct. 15, before dawn
Comet ISON, Mars, and Regulus
An unusual grouping of a comet, a planet and a star, as Comet ISON puts in an early appearance. This image is based on early estimates of ISON’s brightness. It now is known to be nowhere as bright as shown, but may be visible in binoculars.
Credit: Starry Night Software
Wednesday, Oct. 16, after sunset
Venus and Antares
Look just below Venus for the red giant star Antares. If you look carefully, you may also be able to spot Mercury and Saturn.
Wednesday/Thursday, Oct. 16/17, 4:57–7:09 a.m. PDT
Double shadow transit on Jupiter
Observers on the West Coast will have the best chance of seeing this event, which mostly takes place after sunrise in the East.
Friday, Oct. 18, 7:50 p.m. EDT
Penumbral Lunar Eclipse
The Moon will pass through the edge (penumbra) of the Earth’s shadow just after moonrise on the East Coast of North America. This eclipse is very slight, so you will have to look closely so as not to miss it. Look for a shading on the lower half of the Full Moon. It will also be visible in Africa, Europe, and the Middle East.
Friday/Saturday, Oct. 18/19, 2:25–4:37 a.m. EDT
Double shadow transit on Jupiter #2
Most of this event will be visible all across North America.
Friday/Saturday, Oct. 25/26, 4:37–6:31 a.m. EDT
Double Shadow Transit on Jupiter #3
All of this event will be visible all across North America.
Planets
Mercury is well placed in the evening sky for observers in the southern hemisphere, but very low for northern observers.
Venus is now a bright “evening star” setting just after the sun.
Mars is now a bright object in Leo in the morning sky. Mars will have a close encounter with Comet ISON on Oct. 15.
Jupiter is the brightest object in the morning sky all month. It is located in Gemini. There are several double shadow transits this month, plus a very rare triple shadow transit on Oct. 11/12.
Saturn vanishes into evening twilight this month.
Uranus is in opposition on Oct. 3. It is visible in Pisces all night.
Neptune is visible in Aquarius most of the night, setting around 3 a.m.
SKYWATCHING TERMS
- Asterism: A noteworthy or striking pattern of stars within a larger constellation.
- Degrees (measuring the sky): The sky is 360 degrees all the way around, which means roughly 180 degrees from horizon to horizon. It’s easy to measure distances between objects: Your fist on an outstretched arm covers about 10 degrees of sky.
- Visual Magnitude: This is the astronomer’s scale for measuring the brightness of objects in the sky. The dimmest object visible in the night sky under perfectly dark conditions is about magnitude 6.5. Brighter stars are magnitude 2 or 1. The brightest objects get negative numbers. Venus can be as bright as magnitude minus 4.9. The full moon is minus 12.7 and the sun is minus 26.8.
- Terminator: The boundary on the moon between sunlight and shadow.
- Zenith: The point in the sky directly overhead.
NIGHT SKY OBSERVING TIPS
- Adjust to the dark: If you wish to observe faint objects, such as meteors or dim stars, give your eyes at least 15 minutes to adjust to the darkness.
- Light Pollution: Even from a big city, one can see the moon, a handful of bright stars and sometimes the brightest planets. But to fully enjoy the heavens — especially a meteor shower, the constellations, or to see the amazing swath across the sky that represents our view toward the center of the Milky Way Galaxy — rural areas are best for night sky viewing. If you’re stuck in a city or suburban area, a building can be used to block ambient light (or moonlight) to help reveal fainter objects. If you’re in the suburbs, simply turning off outdoor lights can help.
- Prepare for skywatching: If you plan to be out for more than a few minutes, and it’s not a warm summer evening, dress warmer than you think necessary. An hour of observing a winter meteor shower can chill you to the bone. A blanket or lounge chair will prove much more comfortable than standing or sitting in a chair and craning your neck to see overhead.
- Daytime skywatching: When Venus is visible (that is, not in front of or behind the sun) it can often be spotted during the day. But you’ll need to know where to look. A sky map is helpful. When the sun has large sunspots, they can be seen without a telescope. However, it’s unsafe to look at the sun without protective eyewear. See our video on how to safely observe the sun, or our safe sunwatching infographic.
FURTHER READING
Moon Phases: How the lunar cycle works, from full moon to new moon. Also find out when is the next full moon.
Constellations: The history of the Zodiac constellations and their place in night sky observing.
Major Night Sky Events for 2013: A list of skywatching opportunities.
Lunar Eclipses: How they work, plus find out when’s the next lunar eclipse.
Solar Eclipses: How they work, the types, and when the next one occurs.
