Best Space Photos of the Week - March 17, 2013

Canadian astronaut Chris Hadfield is celebrating St. Patrick's Day in style on the International Space Station today (March 17). He’s all decked out in green and snapping photos of Ireland from space. [Full Story]

Kevin Ford, Oleg Novitskiy and Evgeny Tarelkin (left to right) returned to Earth on Friday, March 14, 2013 after a stay on the International Space Station. [See the full photo gallery]

NASA’s Cassini spacecraft has returned its last-ever close-up photos of the icy Saturn moon Rhea. [Full Story]

A NASA spacecraft has captured a rare video of a comet, the Earth and Mercury together. NASA's Stereo-B probe took the video. See NASA's comet video here.

An artist's illustration of a large asteroid headed for Earth. [See the full photo gallery]

Fresh lava flows down Tolbachik volcano in Russia's Kamchatka peninsula in a new space snapshot from NASA's Earth Observing-1 (EO-1) satellite. [Full Story]

The Comet Pan-STARRS may be a challenge to spot in the evening sky, but it still dazzled stargazers around the world when it paired up with the moon Tuesday (March 12). [See the full photo gallery]

In the hot summer months, coastal Californians enjoy cooler weather than inland residents thanks to a cooling offshore vortex called the Catalina Eddy. [Full Story]

A full-scale model of the James Webb Space Telescope model went on display March 8-10, 2013, at the South by Southwest Interactive Festival in Austin, Texas. The telescope stretches a tennis court in length, and stands as tall as a four-story building, NASA's James Webb Space Telescope will succeed Hubble, and JWST represents the largest space telescope ever built. [See More Images]

Astrophotographer Randy Paylor sent in a photo of Comet Pan-STARRS. He writes: "Taken on the campus of Louisiana State University, Baton Rouge, March 11th [2013], with the school's Memorial Tower clock in the foreground. [The photo] was shot across a big open quad to get the tower in the distance and near the horizon." [See More Images]

Astronomer Adam Block, of the Mount Lemmon SkyCenter located north of Tucson, AZ, sent in a photo of spiral galaxies NGC 3169 and NGC 3166. He writes: “This 27-hour cumulative exposure photograph shows just how strongly these two galaxies are interacting. Shells, plumes, arcs of stars and even shared dust lanes are some of the features that highlight this very deep image. NGC 3169 on the left appears to be literally unraveling before our eyes. Perhaps the arc of star clumps below the pair are the remnants of a smaller galaxy that orbited both of them. I am happy to have completed this image just before the flood of comet Pan-STARRS images begin to show up … “ Image submitted March 9, 2013.[See More Images]