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 brightplanets, 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. You can also use astronomy accessories to make your observing easier, and use our Satellite Tracker page powered by N2YO.com to find out when to see the International Space Station and other satellites. 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).
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.
Editor's note: If you have an amazing skywatching photo you'd like to share for a possible story or image gallery, please contact managing editor Tariq Malik at email@example.com.
Summer Stargazing Tips
Planets 'Dance' with the Moon & Perseid Meteor 'Rain' This Month | Video
Find out where you can find Mercury, Venus, Saturn and Mars in the night sky this month. The constellations of Aquarius and Capricornus are great targets this month and an annular solar eclipse will be visible in parts of Africa.
Thursday, September 1 at 5:03a.m. EDT
The moon's orbit carries it between the Earth and sun and appears in the same region of the sky where the sun is. Sunlight is only reaching the side of the moon that is turned away from us, so as a consequence it cannot be seen. Starting a day or two after new moon, you might catch a glimpse of the slender sliver of a waxing crescent moon low near the western horizon, as it gradually pulls away from the sun's vicinity and shifts toward the east.
Friday, September 9 at 7:49 a.m. EDT
First Quarter Moon
After a little over a week, the positions of the Earth, sun, and moon cause us to see one-half of the moon illuminated by the sun. At first quarter, the moon's bright half is on the western (right-hand) side - toward the setting sun. It rises around noontime and sets around midnight, so the moon is visible half the time by day – in the afternoon hours – and the other half at night, during the evening hours. The name quarter moon, even though it's really a "half-moon," refers to the fact that, starting from new moon, our natural satellite has now completely the first quarter of its orbital journey around Earth.
Friday, September 16 at 3:05 p.m. EDT
Full Harvest Moon
The full moon of September, traditionally called the Harvest Moon, always shines in or near the stars of Pisces, the Fishes. Since it's opposite the sun, it rises at sunset and sets at sunrise. At the Autumnal Equinox, around September 22 annually, the tilt of the ecliptic makes a shallow angle with the horizon. On the dates around the Harvest Moon, it appears nearly full and rises at nearly the same time every evening, making it more likely you'll notice it on your daily routine. Some think of the full moon in terms of poetry and romance, but it's a bane to stargazers, lighting up the night sky and dimming or hiding all but the brightest stars.
On this full moon, observers in Europe, Asia, Australia, Africa, and the western Pacific will observe a penumbral lunar eclipse, where the moon passes through earth's shadow, but misses the deepest part, so a minor darkening of the moon is observed. The greatest amount of eclipse occurs on September 16 at 18:55 UT
Friday, September 23 at 5:56 a.m. EDT
Last Quarter Moon
After full phase the moon is now waning, diminishing in illumination every evening. Now the moon rises around midnight and sets near noon. Morning commuters might take note of it, shining high in the south against the blue daytime sky. The bright half is now on the left-hand side, towards the eastern dawning sun. At last quarter, the moon is positioned ahead of the Earth in our trip around the sun. When you see it in the sky, keep in mind that about 3½ hours later, Earth will occupy that same part of space where the moon is now. After last quarter, the moon begins to traverse the last quarter of its orbit in its trip around the Earth as it approaches new moon.
Thursday, September 8 from, sunset to 9 pm EDT
Every few months, for a few hours near the first quarter moon, a feature called the Lunar X becomes visible. When the rims of the craters Parbach, la Caille, and Blanchinus are illuminated from a particular angle of sunlight, they combine to form a small, but very clear and bright X-shape. It's located on the terminator about one third of the way up from the southern pole (bottom) of the Moon. The prominent round crater Werner sits to the lower right. The next Lunar X will form during late afternoon on Thursday, September 8, peak around 7:40 pm EDT,and last until approximately 9 pm. The first quarter moon will be conveniently positioned in the southern sky but, due to twilight, the X won't be best seen after the peak time.
Friday, September 2, 30 to 40 minutes after sunset
Young Moon Meets Jupiter
An exceedingly thin crescent moon, just 1.5 days past new phase, sits less than a finger's width (20 arc-minutes) to the lower left of the planet Jupiter. Scan low above the western horizon with good binoculars to pick them out of the bright evening twilight. Very bright Venus shines about a palm's width to their upper left. Observers in parts of the southwest USA, Central America, the Caribbean, northern South America, and Russia will see the crescent moon pass in front of Jupiter for an hour starting around 22:00 UT.
Saturday, September 3, starting at 07:00 UT
Young Moon Occults Venus
Observers in parts of Central Russia and northern Mongolia will see the crescent moon pass in front of Venus for an hour starting around 07:00 UT.
Saturday, September 3, up to an hour after sunset
Crescent Moon Aligns with Venus and Jupiter
The crescent moon, Venus, and Jupiter form a chain of objects along the evening ecliptic, each separated from the next by about 5 degrees (a hand's width held at arm's length). The moon is higher and to the left, followed by bright Venus, and then much dimmer Jupiter to the lower right. You may need binoculars to see the King of the Planets against the background twilight.
Thursday, September 8
First Quarter Moon meets Mars and Saturn
The First Quarter Moon forms a skinny triangle with Mars and Saturn in the southwestern evening sky. The moon will hover 3 degrees over yellow Saturn while Mars sits 10 degrees (a fist diameter) to the left. The bright red supergiant star Antares sits just below them.
Wednesday, September 21
Last Quarter Moon Covers Taurus the Bull's Eye
On Wednesday, September 21, observers in eastern Africa, the Middle East, central Asia and parts of southern Asia will see the waning gibbous moon cross in front of the bright naked eye star Aldebaran, the star that marks Taurus the Bull's eye. The event, known as an occultation, will last for approximately one hour. The star will disappear behind the leading lit edge of the moon (on the moon's left) and reappearing from behind the opposite darkened half. Binoculars or a small telescope will help, too.
Thursday, September 22 at 10:21 a.m. EDT
On Thursday, September 22 at 10:21 a.m. EDT, the Autumnal Equinox arrives as the sun's apparent eastward motion along the ecliptic carries it across the earth's equator and into the southern hemisphere's sky. As Autumn begins for the northern hemisphere, spring arrives for the southern hemisphere, and six months later, at the Spring Equinox, the sun returns to northern skies. This occurs because the earth's axis of rotation is tilted 23.4 degrees from the plane of its orbit. The word equinox is derived from the Latin for "time of equal night." At the two equinoxes, the axis points neither towards nor away from the sun, so we experience equal parts of daylight and darkness.
As September opens, Mercury completes a poor evening apparition for northerners, but a very good one for southerners. It reaches inferior conjunction with the sun on the evening of September 12. Around September 20 it commences the best morning apparition of the year for northern hemisphere observers, reaching greatest western elongation, its maximum angle away from the sun, on September 28. On that date, it will rise at 5:30 a.m. EDT, well before the sun, and shine brightly against a darkened pre-dawn sky. Also onthat morning, the waning crescent moon, only 6 percent of its disk illuminated, will sit about 10 degrees above Mercury.
Venus is low in the western sky in September, but easier to pick out in the twilight because of its great brightness. Throughout September, Venus sets an hour after the sun. Look for the planet at least 20 degrees (two fist diameters) south of where the sun sets. Venus is in the early stages of a long evening apparition that will last until next spring.
During the first week of September, Jupiter is only observable for a short time after sunset as it drops deeper into the western evening twilight. After that, we lose sight of it as it heads for conjunction with the sun on September 26, and returns as a morning object in October.
Mars, easily visible as a bright red object in the evening southwestern sky, is moving eastward, leaving Scorpius and its rival, the red star Antares, for Ophiuchus as September opens. In mid-month it crosses the Milky Way, and then enters Sagittarius for the last week of September. During this time, it drops in brightness as we increase our distance from it.
Saturn is the modestly bright yellowish object visible in the south-southwest after sunset, above the stars of Scorpius. The ringed planet sets just before midnight in early September, but by 10 p.m. at month's end. Even a modest backyard telescope will reveal the rings, and perhaps some of the larger moons, too.
Uranus is in the eastern evening sky in the constellation Pisces. After it rises just after 9 pm in early September (and around 7:30 p.m. by the start of October), it remains in the sky the rest of the night. At magnitude 6.9, it is not visible to the unaided eye, but binoculars or a small telescope can reveal its tiny blue-green dot. If you compare its position with the surrounding stars, you'll notice that it is moving retrograde, or westward, a trick of parallax caused by earth's faster motion around the sun.
Neptune, in the constellation Aquarius, is a very dim, nearly 8th-magnitude object visible only with very good binoculars or a telescope. On September 2, Neptune reaches opposition, the day of the year when it is opposite the sun. At that time, we are closest to it, and it rises as the Sun sets, making it an all-night target for most of the month. Neptune won't look much larger at opposition because it is still nearly 30 astronomical units (the mean Earth-Sun separation) away. At that distance, its light takes four hours to reach our eyes!
- 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.