When do the Sun and Moon rise and set? When does twilight end and begin? Which planets are up? Start your night of observing with our Astronomical Almanac.
Learn the phase of the Moon tonight, the day you were born, or on any historical date.
Messier 17 (M17) has at least five proper names — Omega Nebula, Horseshoe Nebula, Checkmark Nebula, Swan Nebula, and the Lobster Nebula. Why so many?
Point your telescope towards these doubles — true gems of the late-summer sky. You don’t even need dark skies or a big telescope to admire them!
Use our interactive observing tool to say which of the planet's four largest moons is which.
Calculate when the Great Red Spot will cross Jupiter's central meridian — that's the best time to see the famous storm through your telescope.
Find information on observing Jupiter during its 2016 - 2017 apparition, including information on its moons and Great Red Spot transit predictions.
Take the observing challenge: Find as many as five of the brightest moons of Uranus in a large backyard telescope using our interactive observing tool.
Triton, Neptune's largest moon, is a tricky find. Our Triton Tracker observing tool can help users of moderate to large telescopes spot this distant moon.
To compare what you see on Mars with a map, you need to know which side of the planet you're looking at. Our handy Mars Profiler tells you that and more, for any date and time.
Use this telescope calculator to tell you how changing out eyepieces and accessories will affect your telescope's performance.
Florence, one of the largest Earth-approaching asteroids, gets close enough to see in a small telescope this week and next. Here's how to find it.
The International Space Station passes over virtually all of Earth's populated areas, and you can spot it easily with your eyes alone — if you know where and when to look for it.
The International Space Station often passes close to the Moon, Sun, and naked-eye planets. Use this tool to plan viewing these close encounters.
The Great American Eclipse may be over, but there are some exciting places around the globe getting ready for their own dances with darkness.
If you can't resist taking pictures of the solar eclipse with your smartphone, read this first for tips to ensure quality pictures.
A total eclipse of the Sun is a spectacular sight. With a little preparation and advance planning, you can capture your own souvenir portrait of this awe-inspiring sight.
A total solar eclipse offers the most spectacular of jewels, the diamond ring, as the Moon blocks all but a small part of the Sun's brilliance.
We've gathered some of the best pictures of past solar eclipses, total and partial, from our online photo gallery to serve as inspiration for your eclipse photography
For those photographing the August 21st eclipse, Fred Espenak shares his eclipse photography checklist.
Look for these astronomical and Earthbound phenomena during the total solar eclipse on August 21st.
Due to alarming reports of potentially unsafe eclipse viewers as eclipse day approaches, the American Astronomical Society has revised its safety advice.
What to do if you're caught without optics on eclipse day. Low-tech eclipse viewing options from pinhole to binocular projection.
Summer is perfect for bird-watching whether that be in the trees or among the stars of the Milky Way. We explore the celestial birds of the season.