Two galaxies perform an intricate dance in this new Hubble Space Telescope image. The galaxies, containing a vast number of stars, swing past each other in a graceful performance choreographed by gravity. The pair, known collectively as Arp 87, is one of hundreds of interacting and merging galaxies known in our nearby universe. Arp 87 is in the constellation Leo, the Lion, approximately 300 million light-years away from Earth. These observations were taken in February 2007 with the Wide Field Planetary Camera 2. NASA/ESA/Hubble Heritage/STScI/AURA
In their orbital ballet, Janus and Epimetheus swap positions every four years - one moon moving closer to Saturn, the other moving farther away. The two recently changed positions (the swap occurring on January 21, 2010). Although the moons appear to be close in the image, they are not. Janus (r.) is 113 miles across and Epimetheus is 72 miles across in this view. In fact, even when they are at their closest, tugging at each other and swapping orbital positions, they are never closer than about 9,000 miles. NASA/JPL/Space Science Institute
Backdropped against a blanket of heavy cloud cover, the Russian-built FGB, also called Zarya, nears the Space Shuttle Endeavour and the US-built Node 1, also called Unity (foreground). Inside Endeavour's cabin, the STS-88 crew readies the Remote Manipulator System for Zarya capture as they await the carefully choreographed dance of the rendezvous. NASA
NGC 253, located 10 million light-years away in the southern constellation Sculptor, the Silver Dollar galaxy, or NGC 253, is one of the brightest spiral galaxies in the night sky. In this edge-on view from NASA's Galaxy Evolution Explorer, the wisps of blue represent relatively dustless areas of the galaxy that are actively forming stars. NASA/Caltech-JPL
The larger and more massive galaxy is cataloged as NGC 2207 (l.), and the smaller one on the right is IC 2163. Strong tidal forces from NGC 2207 have distorted the shape of IC 2163, flinging out stars and gas into long streamers stretching out a hundred thousand light-years toward the right-hand edge of the image. Computer simulations, carried out by a team led by Bruce and Debra Elmegreen, demonstrate the leisurely timescale over which galactic collisions occur. Debra Meloy Elmegreen/Vassar College/Bruce G. Elmegreen/IBM Research Division/Michele Kaufman/Ohio State U./Elias Brinks/Universidad de Guanajuato/Curt Struck/Iowa State University/Magnus Thomasson/Onsala Space Obs./Maria Sundin/Goteborg University/Mario Klaric/Columbia/NASA
This image is a still frame from a video presentation of the galaxy collision scientific visualization. After a head-on collision, the galaxies' shapes are strongly disrupted. The tidal forces of gravity have created long plumes of material called 'tidal tails'. The central regions will fall back together relatively quickly and merge into a single remnant galaxy. F. Summers/Space Telescope Science Institute/C. Mihos/Case Western Reserve University/L. Hernquist/Harvard/NASA
A new Hubble Space Telescope image of a celestial object called the Ant Nebula may shed new light on the future demise of our Sun. The Ant Nebula, whose technical name is Mz3, resembles the head and thorax of an ant when observed with ground-based telescopes. The new Hubble image, with 10 times the resolution revealing 100 times more detail, shows the "ant's" body as a pair of fiery lobes protruding from a dying, Sun- like star. NASA/Space Telescope Science Institute
The Advanced Camera for Surveys, the newest camera on the Hubble Space Telescope, has captured a spectacular pair of galaxies. Located 300 million light-years away in the constellation Coma Berenices, the colliding galaxies have been nicknamed "The Mice" because of the long tails of stars and gas emanating from each galaxy. Otherwise known as NGC 4676, the pair will eventually embrace and form a single, giant galaxy. NASA/H. Fort/JHU/G. Illingworth/USCS/LO/M. Clampin/STScI/G. Hartig/ACS Science Team/ESA
The Mars Exploration Rover Opportunity finished observations of the prominent rock outcrop it has been studying during its first 51 martian days, or sols, on Mars. This image from the rover's navigation camera shows the marks of its dance on the surface of an alien world. NASA/JPL
NASA's Hubble Space Telescope Imaging Spectrograph took a series of snapshots of Saturn's aurora dancing in the sky. The ultraviolet images were taken on Jan. 8, 2004. This dissolve sequence shows the aurora appearing as a ring of light circling the planet's polar ring. Collisions with atoms and molecules make the gases in the planet's atmosphere glow in visible, ultraviolet, and infrared light. NASA/ESA/J. Clarke/Boston Univ./G. Bacon/STScI
Riding a wave of frustration at a deep economic recession and austerity measures demanded by other European powers, early results from Greece's election showed the left-wing Syriza with a comfortable lead.
ByRenee Maltezou and Deepa Babbington, Reuters
Greece's Syriza party looks set for a comfortable victory over the ruling conservatives, exit polls and preliminary results from the government showed, with the anti-austerity political upstart receiving strong backing from voters angry at the spending restrictions imposed on the country by the European Union and the IMF so that Greece can pay back its international creditors.