Mercury moves fast around the Sun and changes location in the sky quickly. But you can spot it before sunrise in early November. Here's the info you'll need!
Mars-orbiting spacecraft escaped unscathed by Comet Siding Spring's close approach to the Red Planet — and unique scientific observations are now streaming back to Earth.
A gigantic sunspot group, rotating into view on October 17th, has grown to nearly the size of Jupiter and could trigger potent solar storms in the days ahead.
Just about everyone has heard of Halley's Comet, and each year in mid-October we get to witness a "shooting stars" spawned by this celebrated object.
On October 19th, Comet Siding Spring (C/2013 A1) passes breathtaking close to Mars — as a small army of spacecraft (five of them orbiting the planet) watch.
Images from NASA's Lunar Reconnaissance Orbiter show dozens of small, curious features that might be volcanic eruptions in the past 50 to 100 million years. Countless astronomers, both amateur and professional, have spent untold hours scrutinizing the Moon through telescopes for hints of volcanic activity. Numerous claims of "transient lunar phenomena" (TLP) have been...
Officials proceeded with groundbreaking ceremonies for the world's largest optical telescope on October 7th amid protests from native Hawaiians who oppose it.
You'll need to be up after midnight to watch the Moon plunge deep into Earth's shadow tomorrow morning — but it'll be worth it. Sometimes astronomical events occur in prime time — soon after it gets dark yet before bedtime. But that won't be the case tomorrow morning when, for the second time this year,...
October is pleasant for nighttime observing because evenings are cool and come early. Use our downloadable stargazing podcast to find the month's highlights.
It's a historic day for India's maturing space program, as its first-ever interplanetary explorer successfully slipped into orbit around the Red Planet.
On September 21st, after a 33-minute-long rocket firing, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft slipped into orbit around the Red Planet.
European space officials have decided to drop their Philae lander on November 11th onto the small end of the already-active Comet 67P/Churyumov–Gerasimenko. Success is hardly assured.
Now two years into its exploration of Mars, NASA's big rover has reached the base of the huge mound that scientists hope will reveal the Red Planet's history.
On Wednesday, a powerful X-class flare ripped through the Sun's lower atmosphere and sent a blast wave directly toward Earth that should arrive Friday and produce moderate-to-strong auroras over the weekend.
International Observe the Moon Night is an event that encourages people to "look up" and enjoy our nearest neighbor. This year's InOMN is Saturday, September 6th. Here's a quiz: What astronomical object looks amazing no matter what the magnification, never looks exactly the same no matter how often you view it, and can be...
The astronomical calendar says autumn arrives on September 22nd. It's a season of transition, with plenty of celestial comings and goings in the evening sky. September’s equinox takes place on the 22nd at 10:29 p.m. Eastern Daylight Time. At that moment the Sun shines directly overhead as seen from the equator. Days and nights...
A new measurement, made using radio interferometry, argues that the distance to the Pleiades star cluster measured by ESA's Hipparcos satellite really is wrong — and that ground-based astronomers had it right all along.
On August 25, 1989, a NASA spacecraft made its fourth and final planetary encounter. What it revealed 25 years ago about the Neptunian system is still amazing and still profound.
Late summer offers the Teapot of Sagittarius and the nearby arc of the Scorpion's Tail in the evening, the Perseid meteor shower, and a spectacular pairing of Venus and Jupiter before dawn.
It's not a showstopper, but right now Comet Jacques (C/2014 E2) is poised for telescopic viewing in the hours before dawn.
How did the the innermost planet get its huge iron core? New computer modeling suggests that Mercury is a lucky survivor of chaotic primordial smashups.
Researchers have announced interesting news concerning the Moon, especially about how and when it formed, and why the "Man in the Moon" constantly stares at us whenever the lunar disk is fully lit.
Although its scientific work for NASA ended in the early 1980s, the International Sun-Earth Explorer never quite died — and this week it was revived by a team of volunteers intent on letting it continue exploring interplanetary space.
Sky & Telescope's audio sky tour makes it easy to discover the night sky. During July, the Moon makes very close brushes with Mars and Saturn.
A small asteroid slammed into the Martian surface sometime between March 27 and 28, 2012, creating a crater swarm in the ground. The largest pit is 159 feet across.