SUNSET: 
Fomalhaut's Kuiper Belt
This image from the Hubble Space Telescope's Advanced Camera for Surveys, taken in visible light through a red filter, reveals a belt of icy dust grains surrounding Fomalhaut. The belt extends from 133 to 158 astronomical units from the star, and appears to have a sharp cutoff at both the…
Prospecting for Martian Ice
Scientists combined several images from Mars Express to create this 3-dimensional image of a 35-kilometer-wide (22-mile-wide) unnamed crater in the far northern hemisphere. A patch of water ice sits on the crater floor. The colors are very close to natural, but the vertical relief is exaggerated three times. Due to…
Pluto Reexamined
This true-color map shows how Pluto's surface varies in reflectivity. Eliot Young and his colleagues created this map from data obtained at the McDonald Observatory in Texas during periods when Pluto was being partially eclipsed by its moon Charon. Because the two worlds are tidally locked, the map only shows…
Opportunity Unstuck
One of Opportunity's cameras acquired this image shortly after ground controllers freed the rover from a small sand dune.Courtesy NASA / JPL.
Brown-Dwarf Binary May Challenge Theories
A tightly bound pair of sub-stars in Orion may throw models into disarray.
12 New Saturnian Moons
The circled white dot is one of 12 newly discovered Saturnian moons. This satellite, temporarily designated S/2004 S11, is about 6 kilometers (4 miles) across.Courtesy David Jewitt / Scott Sheppard / Jan Kleyna. There was once a time when the discovery of a single new moon was a landmark event…
"First Exoplanet" Image Confirmed
This infrared image resolves 2M 1207 into a close pair of objects, one of them 100 times brighter than the other. Astronomers infer that their masses are 25 and 5 Jupiter masses, which would make them a brown dwarf and a planet, respectively. Both are glowing with heat left over…
An Exo-Asteroid Belt
This artist's concept shows a massive asteroid belt in orbit around a star with an age and luminosity similar to our Sun. The Spitzer Space Telescope has apparently found such a belt around the star HD 69830.Courtesy NASA / JPL-Caltech / Tim Pyle (SSC). Astronomers have enjoyed considerable success in…
The Milky Way's New Neighbor
Many of the faint stars in this image belong to the newly discovered Ursa Major dwarf galaxy. The 5-by-5-arcminute image, taken with the 3.5-meter telescope at the Apache Point Observatory, covers the inner half of the galaxy.Courtesy Andrew West (University of Washington) / Apache Point Observatory. The Milky Way's family…
Exoplanets: The Heat Is On
Not a pleasant place to be: a hot Jupiter hovers near its parent star. This composite image combines art of an exoplanet and a TRACE satellite image of magnetic loops of hot gas on the Sun.Courtesy David Aguilar (CfA) / TRACE / NASA. For the first time ever, astronomers have…
Hans Bethe
(1906—2005)
Hans Bethe earned the Nobel Prize for determining how stars generate energy. This research remains one of the greatest contributions to our understanding of the universe.Courtesy Cornell University. Hans Bethe, one of the towering figures of 20th-century astrophysics, died on Sunday, March 6th, at his home in Ithaca, New York,…
Einstein Passes New Tests
A binary pulsar system provides an excellent laboratory for testing some of the most bizarre predictions of general relativity. The two pulsars in the J0737-3039 system are actually very far apart compared to their sizes. In a true scale model, if the pulsars were the sizes of marbles, they would…
Opportunity Finds an Iron Meteorite
Tests have confirmed that the basketball-size Heat Shield Rock, imaged here by Opportunity's panoramic camera, is a meteorite composed primarily of iron and nickel. Note the small 'blueberries' that surround the meteorite.Courtesy NASA / JPL / Cornell University. On December 21, 2004, the Mars Exploration Rover Opportunity arrived at its…
Hooray for Huygens!
As Huygens descended through the atmosphere of Titan, the probe recorded this system of stubby, interconnected channels leading to an apparent shoreline. The scene is about 5 kilometers (3 miles) wide.Courtesy ESA/NASA/University of Arizona. Move over, Mars! Saturn's large moon Titan is now the most distant world touched by the…
Intriguing Iapetus
This Cassini image shows Iapetus's leading hemisphere, most of which is as dark as an asphalt parking lot. Scientists were amazed to find a giant ridge girdling at least one-third of the moon's circumference. The highest peaks along the ridge are about 20 kilometers (12 miles) high, which rivals Mars's…
Uranus Weather Picks Up
If you had to vote for the most boring planet, you might pick Uranus. But recent near-infrared images demonstrate the old maxim that first impressions can be deceiving.
Mars Methane Boosts Chances for Life
Two independent teams have reported new tantalizing evidence of Martian methane — a gas possibly suggestive of current life on the red planet.
The Dwindling Kuiper Belt
Following observations by several teams with various telescopes, astronomers are realizing that Kuiper-Belt objects are generally smaller than previously thought.
More Science Findings From Cassini
Scientists at the American Astronomical Society's Division of Planetary Sciences Meeting in Louisville, Kentucky, were treated to a slew of results from the Cassini spacecraft.
Asteroids Tell Tale of Jupiter Migration
Scientists assembled this Jupiter mosaic from a series of Cassini images taken during the December 2000 flyby. New research suggests that Jupiter formed farther from the Sun and migrated in to its present orbit.Courtesy NASA / JPL / Space Science Institute. In 1984 astrophysicists Julio A. Fernández and Wing-Huen Ip…
