Space Photos This Week: Mars Gullies, Odd Galaxy, More

Mars Gullies in Motion?

Image courtesy NASA/JPL/University of Arizona

These gullies in a Martian crater might be proof that the red planet has liquid water currently flowing on its surface, scientists said in a paper published March 26, 2010.

The gullies in Russell Crater—seen above in a 2008 picture from the HiRISE camera on NASA's Mars Reconnaissance Orbiter—end abruptly rather than forming fans, as would be expected if the gullies had been made by dry material flowing downhill. The gullies were also seen to grow over time.

Scientists think the best explanation for the gullies is that seasonal melting of nearby water ice creates slurries of sand and liquid water, which flow down the crater's dunes.

Published April 14, 2010

Satellite's Fire and Ice

Photograph by Stephanie Corvaja, ESA

Sometimes it takes a little fire to crack the code of Earth's ice. Europe's first space mission to study terrestrial ice got an explosive start on April 8, when a rocket (pictured) launched the European Space Agency's CryoSat-2 satellite from the Baikonur Cosmodrome in Kazakhstan. (See an illustration of CryoSat-2 in orbit.)

The original CryoSat had been lost in 2005, when a rocket failure caused the satellite to crash into the sea during launch. The project is intended to precisely measure the changing thicknesses of sea ice and ice sheets to monitor how they're responding to global warming.

Published April 14, 2010

Imperfect Spiral

Image courtesy NASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

The largest member of the Leo Triplet, the galaxy known as Messier 66 shows off its unusual asymmetry in striking detail in a new picture from the NASA/ESA Hubble Space Telescope released April 8, 2010.

The galactic trio is close enough to interact, and astronomers think the gravitational pulls of the other two Leo galaxies are deforming the classic spiral of M66. Unlike other spiral galaxies, including our own Milky Way, M66 has mismatched arms, and the galaxy's central core has been displaced.

Published April 14, 2010

Cracked Crust

Image courtesy NASA/JPL/University of Arizona

Shifted due to centuries of seismic pressures, rock layers near Mars's equator lie cracked and out of whack in a high-resolution satellite picture released April 7, 2010.

Captured by the HiRISE camera aboard NASA's Mars Reconnaissance Orbiter on March 1, the bold stripes of the various layers make it easy for scientists to gauge just how far the crust has been offset at each fault.

Published April 14, 2010