Space in Month

Happy birthday, Hubble

To celebrate the 21st anniversary of the Hubble Space Telescope's deployment into space, astronomers pointed Hubble's eye at an especially photogenic pair of interacting galaxies called Arp 273. The larger of the spiral galaxies, known as UGC 1810, has a disk that is distorted into a roselike shape by the gravitational tidal pull of the companion galaxy below it, UGC 1813. This image, released April 20, is a composite of image data gathered by Hubble's Wide Field Camera 3.

Spaceflight's golden anniversary

Spectators at Moscow's Victory Park watch fireworks set off to celebrate the 50th anniversary of Soviet cosmonaut Yuri Gagarin's historic spaceflight on April 12. The date, which marks the first-ever human flight into space, is celebrated annually in Russia as Cosmonautics Day and in the rest of the world as Yuri's Night.

A loopy nebula

This image of the nebula NGC 3582, released April 13, was captured by the Wide Field Imager on the MPG/ESO 2.2-meter telescope at the European Southern Observatory's La Silla Observatory in Chile. The nebula's giant loops of gas bear a striking resemblance to solar prominences. These loops are thought to have been ejected by dying stars, but new stars are also being born within this stellar nursery. These energetic youngsters emit intense ultraviolet radiation that makes the gas in the nebula glow, producing the fiery display shown here.

Milky Way beyond the clouds

The Milky Way galaxy sparkles in a clear spot of sky above as a Saharan sandstorm sweeps past Mount Teide in the Canary Islands. Norwegian photographer Terje Sorgjerd captured the sight during a visit to the Spanish archipelago.

Double volcano

A mosaic image from Europe's Mars Express orbiter, released April 1, shows side-by-side volcanoes in the Tharsis region of Mars. Ceraunius Tholus, at left, is 80 miles across and rises nearly three and a half miles above its surroundings. Its neighbor, Uranius Tholus, is nearly 40 miles across and three miles high. Icy clouds can be seen drifting past Ceraunius Tholus' summit on one part of the picture, but the clouds dissipated before the orbiter could gather the data for the lower portion of the image.

Getting the rover ready

NASA engineers stand by a conical shell that will help protect the Curiosity rover, a robot the size of a car, from the searing temperatures of atmospheric entry when it lands on Mars next year. This picture of the rover preparations was taken at NASA's Jet Propulsion Laboratory on April 4. Curiosity is due for launch in November.

Ready, set, launch

Workers prepare a Russian Soyuz rocket on April 1 for the launch of a crew capsule from the Baikonur Cosmodrome in Kazakhstan to the International Space Station. The launch went off successfully on April 5.

Lens focuses on cosmic frontier

Abell 383, the giant cluster of elliptical galaxies in the center of this Hubble image, contains so much dark matter that its gravity bends light. The cluster's gravitational field thus acts as a "magnifying glass" for more distant galaxies. Astronomers reported on April 12 that the gravitational lens is producing a magnified view of a galaxy so far away that we see it as it was less than a billion years after the big bang.

Streaks on Mercury

This is one of the first color images captured by NASA's Messenger probe after entering orbit around Mercury. The picture, looking toward Mercury's horizon, was acquired as the spacecraft was flying northward along the first orbit during which its dual-camera system was turned on. Bright rays from Hokusai Crater can be seen running north to south.

All dressed up

Space shuttle commander Mark Kelly leads other members of Endeavour's crew, including Greg Chamitoff, Mike Fincke and Drew Feustel, out of the Operations and Checkout Building at Kennedy Space Center in Florida on April 1. Kelly and his STS-134 crewmates went through all the launch-day routines as a rehearsal for Endeavour's final space mission.

Flight through the lights

Greenish northern lights ripple through the sky above the wing of a commercial airliner during a night flight from San Francisco to Paris.

Saturn's spots and stripes

Shadows cast by Saturn's rings darken the southern hemisphere of the planet in this image from the Cassini orbiter, released April 25. The Saturnian moon Tethys can be seen toward the image's right side, and the tiny moon Epimetheus is visible as a spot just beneath the rings.

Slithering river

The Parana River snakes through Argentina in this image, taken by Italian astronaut Paolo Nespoli from the International Space Station on April 9.

Blue moon

A jet plane leaves a trail of exhaust in the sky, next to a beautiful crescent moon, as it flies over Sieversdorf in Germany on April 10.

Give him a hand

Russian ground-crew workers help U.S. astronaut Ron Garan stand up after a spacesuit inspection in preparation for his launch to the International Space Station aboard a Soyuz spacecraft on April 5. Garan and two Russian cosmonauts blasted off just days before the 50th anniversary of the first spaceflight, in a Soyuz craft named after first spaceman Yuri Gagarin.

Golden Gate ... to space?

A new Virgin America A320 jet, aptly named "My Other Ride Is a Spaceship," flies in tandem with the SpaceShipTwo rocket plane and its mothership over the Golden Gate Bridge on April 6. The aircraft landed at San Francisco International Airport, becoming the first planes to arrive at the new $388 million, 640,000-square-foot Terminal 2. SpaceShipTwo is expected to begin rocket-powered suborbital test flights sometime in the next year - not from San Francisco, but from the Mojave Air and Space Port near Los Angeles.

Sonic boom in space

Dense filaments of gas stretch out for tens of light-years in the IC5146 interstellar cloud. This image, released April 13, was taken by the European Space Agency's Herschel space observatory in infrared wavelengths. Stars are forming along these filaments, which scientists say may result from interstellar shock waves - basically, sonic booms that travel through the thin gas contained in our galaxy.

Window on the world

The seas and clouds of Earth swirl below in an April 21 picture taken by NASA astronaut Ron Garan from the International Space Station in honor of Earth Day. Russian transport spacecraft are docked to the station's ports in the foreground.

Craggy coast

Blue water and brown islets make for a dramatic picture of Western Australia's Kimberley coastline, as seen from the International Space Station on April 12.

Orion's big head

An infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE, reveals a giant nebula around the star Lambda Orionis, inflating the "head" of the constellation Orion to huge proportions. The bright blue star in the lower left corner of the April 14 image is Betelgeuse. In visible light, the supergiant star shines red, but it takes on a bluish appearance in WISE's color-coded infrared view.