SUNSET: 
March Madness on Mercury
After a full year of scrutiny by NASA's Messenger orbiter, the innermost planet is revealing itself to be unique — and downright confounding — to the project's scientists.
How Big is the Sun, Really?
By carefully recording the track of Mercury when it crossed the solar disk in 2003 and 2006, observers have measured the Sun's diameter more accurately than ever before.
The Moon Visits Jupiter and Venus
The crescent Moon visits Jupiter on the evening of Sunday, March 25th, and it visits Venus on Monday night.
Twin-Eyed Telescope Sees Sharp Stars
The Large Binocular Telescope has opened one of its new eyes on the sky, revealing exoplanets and stars with a precision that rivals the best ground-based observatories astronomers have.
June 4th's Partial Eclipse of the Moon
On the morning of Monday, June 4th, skywatchers in the Americas can catch a partial lunar eclipse low in the western sky before and/or during dawn.
WISE's Grand View of the Infrared Sky
In just 10 months during 2010, an orbiting observatory meticulously recorded a "heat map" of the entire celestial sphere, revealing unseen beauty in the Milky Way and providing astronomers with a catalog of more than a half billion celestial objects.
Colorful Cluster Transformation
Astronomers have spotted a unique galaxy cluster at a surprisingly far distance from Earth. The close mixing of lively and “red-and-dead” galaxies suggests an important transitional period in galaxy cluster evolution — when star formation shuts off.
The Ultimate Mobile Guide to Saturn
Our new SaturnMoons app guides you around the ringed planet as it brightens in the night sky in advance of an April 28th opposition. Learn about Saturn's bizarre satellite family, then find the moons in your own scope.
Portrait of an Angry Sun
The source of titanic flares this past week, active region 11429 has just rotated off the Sun's disk. But it didn't escape before being captured in all its angry glory by Alan Friedman from his backyard in Buffalo, New York. Here's how he did it.
Smooth Sailing on Titan
Waves don't grow much — if at all — on Saturn's moon Titan. However, the calm lakes and seas might see some surface wrinkles in a few years when the northern hemisphere's summer arrives.
A Potpourri of Lunar Results
It's been nearly 40 years since Apollo astronauts last set foot on the lunar landscape. Yet, as a sampling of recent research efforts shows, we're a long way from answering all our questions about the Moon's formation and evolution.
Tom Johnson, 1923–2012
The genius who designed the modern Schmidt-Cassegrain telescope, and then shaped its role in changing the face of amateur astronomy, died on Tuesday.
Distant Galaxies Hint at Exotic Physics
Observations of galaxies shooting high-powered jets from their cores suggest the existence of a hypothetical particle. While speculative, the results could mean that photons aren't as dependable as we envision them to be.
Aurora Alert — Check Your Skies
A huge coronal mass ejection from the Sun struck Earth's magnetic field around 11:00 UT (6 a.m. EST or 3 a.m. PST) on Thursday, March 8th.
New Fuel for Type Ia Supernova Debate
The origin of the stellar explosions known as Type Ia supernovae has been a topic of hot debate for decades. A new study adds fuel to the fire.
Jupiter Meets Venus
Jupiter and Venus have just crossed paths in the sky. From The two planets are within 5° of each other from March 9th to 17th, fitting in a single field of view through most binoculars.
Mars Takes Center Stage
The Red Planet (actually yellow-orange) is the brilliant "star" climbing steadily in the east these evenings. Now's your best chance to examine our next-out planetary neighbor.
Transit of Venus: June 5–6, 2012
On June 5th (in the Western Hemisphere) or June 6th (in the Eastern Hemisphere), Venus will pass across the face of the Sun for the second time in 8 years — and for the last time until 2117.
May 20th's Solar Eclipse — S&T Reports
Two editors headed to California, and a third to New Mexico, for May 20th's solar eclipse. Read their reports, along with those from S&T readers and featured pictures from our online photo gallery. We want to hear from you too!
May 20th's Annular Eclipse of the Sun
On Sunday afternoon, those in central or western United States will have a "ringside" seat to the annular eclipse. Look here for links to last-minute planning tools — including weather forecasts along the track!
