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. 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 Chris Vaughan 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 firstname.lastname@example.org.
Sky Maps and Video Guides
Best Night Sky Events of May 2017 (Stargazing Maps)
See what's up in the night sky for May 2017, including stargazing events and the moon's phases, in this Space.com gallery courtesy of Starry Night Software.
Planets, Constellations and Eta Aquarid Meteors In May 2017 Skywatching | Video
Mars and Jupiter are the evening planets while Saturn and Venus are visible in the morning. The Virgo constellation is a great target this month. On the night of May 4-5, the Eta Aquarid meteor shower peaks with up to 10 meteors per hour.
Tuesday, May 2 at 10:47 p.m. EDT - First Quarter Moon
At first quarter, the positions of the Earth, sun, and moon cause us to see one-half of the moon illuminated by the sun. The moon's lit 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" shape, refers to the fact that our natural satellite has now completely the first quarter of its orbital journey around Earth since the last new moon.
Wednesday, May 10 at 5:21 p.m. EDT - Full Milk Moon
The May full moon, known as the "Full Milk Moon", "Full Flower Moon", or "Full Corn Planting Moon", always shines in or near the stars of Libra. It rises around sunset and sets around sunrise. This is 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.
Thursday, May 18 at 8:33 p.m. EDT - Last Quarter Moon
Last quarter moons rise around midnight, and morning commuters often spot it in the southern daytime sky. It's illuminated 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. About 3½ hours later, earth will occupy that same point in space. After last quarter, the moon wanes while traversing the last quarter of its orbit around the earth as it approaches new moon.
Thursday, May 25 at 3:44 p.m. EDT - New Moon
At new moon, the moon's orbit carries it between the earth and sun - 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 it cannot be seen. The moon's 5 degree tilted orbit usually carries it above or below the sun, but solar eclipses occur when the moon is close to the ecliptic at new moon. 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.
Wednesday, May 3-4 overnight – Moon meets Regulus
Overnight on Wednesday, May 3, the orbital motion of the waxing gibbous moon (green line) will bring it within a few degrees of the bright star Regulus in Leo. Observers across Indonesia, Australia, and New Zealand will see the moon occult the star around 10:00 UT.
Saturday, May 6 pre-dawn - Eta-Aquariid meteors peak
The annual Eta Aquariid Meteor Shower, produced by material from Halley's Comet, runs from Apr 19 to May 26 and peaks before dawn on Sat., May 6. The meteors will travel away from the radiant point in Aquarius, near the eastern horizon. Watch for up to a few dozen meteors per hour, including some fireballs, near the peak. The waxing gibbous Moon will degrade the shower a little.
Sunday, May 7 evening – Mars near Aldebaran
On Sunday, May 7, reddish Mars will pass within about 6 degrees to the upper right of the orange giant star Aldebaran in Taurus. While similar in appearance, the distant star will outshine the planet.
Sunday, May 7 all night – Moon meets Jupiter and Spica
On Sunday, May 7, Jupiter, the nearly full moon, and the bright star Spica will appear together in the eastern sky starting about 6:30 pm local time. The moon and Jupiter will fit within a binocular field of view and make a nice photo opportunity. The three objects will cross the night sky together and be visible low in the western sky before 5 am local time.
Thursday, May 11 at 9:59 p.m. - Double shadow transit on Jupiter
Thursday, May 11, 9:59 to 10:05 p.m. EDT, The shadows of Io and Europa will briefly cross Jupiter simultaneously. Io will lead it shadow across, while Europa, orbiting farther from the planet, has cleared the disk (at upper right).
May 13-14 pre-dawn – Moon meets Saturn
In the small hours of Saturday, May 13, the waning gibbous moon will sit 7 degrees to the upper right of Saturn in the southeastern sky. The pair will move above the southern horizon by dawn. The following day, the moon will jump to Saturn's left.
Thursday, May 18 before dawn - Mercury at Greatest Western Elongation
On Thursday, May 18, before dawn, Mercury will reach its greatest angle west of the sun. With Mercury below a shallow ecliptic, this is a very poor apparition for mid-northern latitude observers, but a good one for the southern hemisphere.
Thursday, May 18 at 11:53 p.m. - Double shadow transit on Jupiter
Thursday, May 18, 11:53 p.m. to 12:40 a.m. EDT, The shadows of Io and Europa will cross Jupiter simultaneously. Io will lead it shadow across, while Europa, orbiting farther from the planet, has cleared the disk (at right).
Saturday, May 20 predawn – Moon meets Neptune
For about two hours after the waning crescent moon rises at 1:30 am local time on Saturday, May 20, use your telescope to look for tiny blue Neptune sitting less than 2 degrees to its upper right.
Monday, May 22 pre-dawn – Moon meets Venus
In the eastern pre-dawn sky on Monday, May 22, Venus and the old crescent moon will rise together about 4 am local time. The moon will be about 4 degrees to the lower right of the bright planet. Viewed in a telescope, Venus will show a similar crescent phase.
Tuesday, May 23 pre-dawn – Moon meets Mercury
In the eastern pre-dawn sky on Tuesday, May 23, the old crescent moon will sit 9 degrees to the upper left of Mercury. Both objects will be embedded in the dawn's glow.
Friday, May 26 at 1:47 a.m. EDT - Double shadow transit on Jupiter
Friday, May 26, 1:47 a.m. to 3:14 a.m. EDT, The shadows of Io and Europa will cross Jupiter simultaneously. Io will lead it shadow across, while Europa, orbiting farther from the planet, has cleared the disk (at right).
Wednesday, May 31 evening – Moon and Regulus
On Wednesday evening, May 31, the waxing crescent moon will sit about 5 degrees from the bright star Regulus in Leo. Observers in parts of South America and Central Africa will see the moon occult the star around 17:00 UT.
As May opens, Mercury has commenced a poor morning apparition for mid-northern latitude observers, but an excellent one for the southern hemisphere. Peak visibility occurs between 5 and 5:30 am local time after mid-month, when it's low in the east. On Thursday, May 18, Mercury reaches its greatest angle west of the sun. As the month closes, it has started to slowly swing sunwards towards superior conjunction next month.
During May, Venus shines brightly in the eastern pre-dawn sky amid the stars of western Pisces. The planet's disk will appear as a thin crescent that waxes toward a half-lit phase through the month while shrinking in apparent diameter. Due to a shallow morning ecliptic, Venus will not climb very high above the horizon before the sun rises. On Monday morning, May 22, Venus and the old crescent moon will rise together about 4 am local time, with the moon about 4 degrees to the lower right of the bright planet.
All month, reddish Mars remains in the western early evening sky amid the stars of Taurus. Although setting shortly after 10 pm local time, it will steadily descend into the evening twilight. It continues to drop in brightness and disk size as we pull farther away from it.
Perfectly positioned for observing all month, very bright Jupiter moves retrograde through the body of Virgo, in the southern evening sky. It will remain about 10 degrees above that constellation's brightest star Spica. The shadows of Jupiter's four Galilean moons frequently cross the planet's disk this month, including a number of double shadow events. On Sunday, May 7, the waxing gibbous moon will sit about two degrees from Jupiter, making a nice sight in binoculars, and a nice photo opportunity.
Yellowish Saturn spends May near the Milky Way, moving retrograde at the border of Sagittarius and Ophiuchus. All month long, it rises in the east in late evening and can be spotted low in the southern sky until just before dawn. In the small hours of Saturday, May 13, the waning gibbous moon will sit 7 degrees to the upper right of Saturn in the southeastern sky. A day later, the moon will jump to Saturn's left.
After its recent solar conjunction, Uranus spends May slowly climbing away from the sun in the pre-dawn sky. By the last week of the month, it should be observable from mid-northern latitudes – sooner for southern latitudes.
Neptune is very low in the eastern pre-dawn sky during May,in the constellation of Aquarius. As the month opens, it rises about 4 am local time, moving to 2 am by month end. For about two hours after 1:30 am local time on Saturday, May 20, use your telescope to look for tiny blue Neptune sitting less than 2 degrees to the upper right of the waning crescent moon.
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, while a finger covers about one degree.
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.