SUNSET: 
Geologic Map Shows What's Where on Vesta
NASA's Dawn spacecraft spent 14 months photographing Vesta from close range. Now geologists have completed a global map of the asteroid's surface geology.
New Horizons Awakens for Pluto Encounter
Right on cue, New Horizons spacecraft has awakened from its final electronic hibernation. Seven months from now, it will make the first-ever visit to Pluto.
Warm Up with December's Geminid Meteors
The annual Geminid meteor shower, one of the best shooting-star displays each year, returns to our skies late this week. Despite interference from moonlight, plenty of bright meteors should still shine through.
Tour December's Sky: Orion Rising
Our monthly podcast offers the key highlights for stargazing in December: where to find bright stars and planets — and how to spot the Geminid meteor shower.
Why is Jupiter's Great Red Spot … Red?
Scientists think they've figured out what causes the mysterious ruddy coloring in the giant planet's enormous oval storm.
Philae Wins Race to Return Comet Findings
With its battery power failing, Philae became the "little lander than could" and managed to return results from all 10 of its science instruments before slipping into hibernation.
Eight Billion Asteroids in the Oort Cloud?
A fresh look at a nagging problem — asteroids moving in comet-like orbits — concludes that asteroids must make up about 4% of the vast, distant Oort Cloud of comets. When a telescope atop Hawaii's Haleakala swept up a fast-moving object in August 1996, astronomers didn't know what to make…
Rosetta Update: The Scent of a Comet
The Rosetta spacecraft reached its objective, Comet 67P/Churyumov-Gerasimenko, in August. Since then, one instrument has been "smelling" the mix of gases escaping from the comet's nucleus.
Tour November's Sky: Cassiopeia
A mythic drama plays out in the stars above on November evenings. Taking center stage, almost directly overhead at nightfall, is Cassiopeia, the Queen.
Where, When, and How to See Mercury
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!
Spacecraft Observe Comet Siding Spring
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.
Jupiter-size Sunspot Group Now in View
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.
Dark Skies for 2014's Orionid Meteor Shower
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.
Comet Siding Spring Skims Past Mars
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.
(Geologically) Recent Volcanoes on the Moon?
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…
Work Begins on Thirty Meter Telescope
Officials proceeded with groundbreaking ceremonies for the world's largest optical telescope on October 7th amid protests from native Hawaiians who oppose it.
Night Owls Prepare for October 8th's Lunar Eclipse
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…
Tour October's Sky: Pegasus Flies High!
October is pleasant for nighttime observing because evenings are cool and come early. Use our downloadable stargazing podcast to find the month's highlights.
India's Mars Orbiter Mission Arrives Safely
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.
MAVEN Makes It to Mars
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.
