Left: Infrared image of one planet orbiting HR 8799. Right: Isolated dots are planets; multicolored ball is residual light from HR 8799.
National Research Council Canada
Artist's conception of the HR 8799 system, in which the three planets orbit the star at distances similar to those of Saturn, Uranus and Neptune.
Gemini Observatory; Artwork by Lynette Cook
Relative positions and orientations of the HR 8799 system, lower left, our own solar system, center, and the Milky Way's disk (the large flat circle).
A Hubble Space Telescope image from 2006 of the debris belt around the nearby star Fomalhaut. A planet, inset, is clearly visible.
Paul Kalas/UC Berkeley; STScI
The full Eye-of-Sauron-like 2006 image of the dust disk surrounding Fomalhaut.
An artist's impression of a scorching extrasolar planet looming close to its parent star in the background.
ESA/NASA/Geneva University Observatory
A false-color image of the trench informally named 'La Mancha,' taken by NASA's Phoenix Mars Lander's Surface Stereo Imager on Oct. 7, about a month before its signals were lost for good. The white area exposed just beneath the surface is probably water ice.
NASA/JPL-Caltech/U. of Ariz./Texas A&M
Bright green areas in this image of the Martian surface show carbonate deposits,, which indicate the Red Planet may once have been suitable for life.
NASA/JPL/JHUAPL/U. of Ariz./Brown U.
Tracks left behind by a glacier on Mars.
Mars' north polar ice cap, as spotted by the Mars Reconnaissance Orbiter
An artist's impression of a black hole seen from directly 'above' the event horizon.
An artist's conception of the two colliding galaxies of the 4C60.07 system, each with a massive black hole at its center.
David A. Hardy/UK ATC
An artist's conception of a huge gamma-ray burst generated by a black hole being born, with material shot outward in a two-component jet (white and green beams).
NASA/Swift/Mary Pat Hrybyk-Keith and John Jones
A composite image of Mercury. The blank patches are areas that were not imaged.
Mercury seen in color by the MESSENGER space probe.
A close-up of Mercury's surface, where volcanoes spew 'mysterious dark blue material.'
A photo of a nebula near the star cluster NGC 2074 released to commemorate the Hubble Space Telescope's 100,000th orbit around the Earth.