SUNSET: 
Comet ISON Spotted Again, Faintly
Comet ISON has been imaged low in the dawn at only 14th magnitude. This suggests a modest showing late this year for the supposed "comet of the century."
Under Stress, Asteroids May Be Fragile
A new microgravity experiment demonstrates the weird, unstable fluidity of asteroid surfaces, with potential consequences for visiting craft.
What Powers the Van Allen Belts?
Thanks to a pair of NASA probes launched last year, space physicists have confirmed that relativistic electrons in the radiation belts surrounding Earth arise from "homegrown" acceleration processes.
The Weakest Solar Cycle in 100 Years
Scientists are struggling to explain the Sun’s bizarre recent behavior. Is it a fluke, or a sign of a deeper trend?
Wave at Saturn (But Will Cassini See You?)
Cassini is taking our picture on Friday, but how much light do we humans actually reflect? We've crunched the numbers, and the answer may surprise you.
A Fix for the "Faint Young Sun"
For 40 years astrobiologists have wrestled with how to make the early Earth warm enough to support life even though the young Sun was at least 30% fainter than it is now. New climate models, powered by supercomputers, are converging on a solution.
The Sun's Heat Wave
Astronomers at the American Astronomical Society's Solar Physics Division meeting discussed new evidence that magnetic waves are the reason our star's corona is blazing hot.
Neptune's Newest Moon
Using Hubble images taken in several patches over a six-year period, astronomers have spotted a tiny object circling Neptune. This find, the first in a decade, brings the planet's moon count to 14.
A Tale of the Sun's Tail
Using observations from NASA's Interstellar Boundary Explorer, space physicists now realize that the solar wind forms a tail that likely extends light-years downwind from the Sun across interstellar space.
Chelyabinsk Mega-meteor: Status Report
The cosmic intruder that exploded in the sky on February 15th dropped thousands of fragments onto the snow-covered plains of south-central Russia. Here's an update on what's been found.
Winds on Venus: Getting Stronger
The hurricane-like winds at Venus's cloudtops have steadily become faster since 2006 — and planetary scientists have no idea why it's happening.
Big Science with Modest Scopes
A recent annual meeting of amateur astronomers in Big Bear, California, proved once again that the amateur community is pursuing impressive science endeavors.
Biggish Asteroid 1998 QE2 Pays Earth a Visit
This week's visit by asteroid 1998 QE2 is just a courtesy call, as it passes by on May 31st at 15 times the Moon's distance. A NASA radar team has already discovered that this big space rock has a sizable companion.
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.
