SUNSET: 
Lots of Rocks Hit the Moon and Mars
Thanks to high-definition cameras or orbiting spacecraft, planetary geologists are getting their first reliable stats for the impact rates on our neighbor worlds.
A Bright Flash in the (Lunar) Night
If you'd been watching the Moon at just the right moment on March 17th, you might have seen a brief starlike flash created when a beachball-size rock slammed into the lunar surface.
Uranus & Neptune: Thin Weather Layers
The solar system's "ice giants" display surprisingly energetic weather patterns — and a new analysis suggests they're all confined to a very thin outer layer on each planet.
Earth and Moon: Sharing a Drink
New analysis of Apollo samples shows that water trapped in eruptions from the Moon's interior have the same isotopic fingerprint as terrestrial water — a key confirmation that the Moon formed after something big hit Earth.
Lingering Echoes of Comet S-L 9's Demise
It's been nearly 19 years since fragments of Comet Shoemaker-Levy 9 slammed into Jupiter. Recent observations show that water delivered by the comet still lingers in the planet's stratosphere.
Saturn is Making Waves
Just as it's coming closest to Earth, the big ringed planet is in the news in multiple ways — including the discovery of a long-lasting hurricane at its north pole.
A Tumbling Apophis: Good News for Earth
Careful observations of asteroid 99942 last January show it to be both elongated and tumbling — which is good news to the celestial dynamicists trying to predict this body's future close brushes with Earth.
NASA to Snag a Near-Earth Asteroid
Not content to let private companies have all the fun in asteroid exploration and exploitation, NASA managers have proposed a high-flying mission that would capture a small asteroid and dispatch astronauts to study it — all within the next decade.
Is Saturn's Family Showing Its Age?
A detailed analysis of Cassini images suggests that the rings of moons of Saturn are ancient creations that in recent times have been coated to varying degrees by a dark, reddish patina.
Curiosity Wades Into Mudstone and More
In the six months since it landed onto the floor of Gale crater, NASA's newest rover has found plenty of evidence that this bit of Mars was soaking wet — and probably more than once.
Radar Reveals Martian Flood Channels
Using a ground-penetrating radar instrument, researchers have "unearthed" new details about one of the Red Planet's most recent catastrophic floods.
Watching GRAIL's Demise
When a pair of small spacecraft crashed into a mountain on the Moon last December 17th, NASA's eagle-eyed Lunar Reconnaissance Orbiter looked on — and recorded not only the debris kicked up by each impact but also the tiny craters they made.
Habitable Oasis on Mars?
The results from the Curiosity rover's first rock-drilling are in: the rock formed in the presence of fairly neutral, not-too-salty water and has a chemical makeup that might have provided energy for microorganisms.
Update on Russia's Mega-Meteor
The cosmic intruder that exploded so spectacularly over Chelyabinsk last month was a typical asteroidal fragment. Now researchers are piecing together the story of its arrival and aftermath.
Mars has Front-Row Seat for 2014 Comet
Comet Siding Spring (C/2013 A1) has a small chance of striking the Red Planet in October 2014. It'll likely miss — but come close enough to put on a spectacular show for spacecraft on or near the planet.
Earth Briefly Gains Third Radiation Belt
Last September, just days after launching twin spacecraft deep into Earth's magnetosphere, space physicists discovered a third region of trapped high-energy particles in the Van Allen radiation belts.
Scorching Rain on the Sun
NASA's Solar Dynamic Observatory captures "coronal rain," a beautiful and mysterious phenomenon on the Sun.
Info on Russian Meteor Pours In
The fireball that exploded over Russia on February 15th left more than a million square feet of damaged windows, bringing home how fragile life on Earth can be. Here's what S&T's staff has managed to piece together about what happened.
"Black Rain" on Callisto and Ganymede
Those distant, dinky irregular moons of Jupiter are likely responsible for deep drifts of dark dirt on the two largest Galilean satellites.
Lessons from the Russian Meteor Blast
Friday's meteorite explosion over Russia offers the strongest motivation yet for investigation of near-Earth objects.
