Home movies from space

For a space traveler's view of remarkable events that unfolded this past year in and around the solar system, look no further than the JPL website, where a series of digital videos offers spectacular images of Earth, Mars and the far corners of our solar system.

"2010: A Year in Pictures from JPL/NASA" is a fast-moving collection of stills and video clips ranging from space observations of Haiti's devastating earthquake to an electrical storm over the surface of Saturn to colorful infrared images of star formation at the edge of the Milky Way.

The website also features a short time-elapsed video of the blue-hued Martian sunset, captured in early November by the panoramic cameras of the JPL Mars rover Opportunity.

It's the closest thing to standing on the surface of the Red Planet.

"If you were standing right there it would look about the same, with the exception that we had to dim the sun. It's so bright you [otherwise] couldn't look at it without squinting," said Mark Lemmon, a Mars rover science team member who works out of Texas A&M University.

Unlike a sunset seen from Earth, where light reacts with the atmosphere to produce a reddening effect, sunsets on Mars take on hues of blue.

On Mars the atmosphere is thin and large airborne dust particles plentiful, so light from the setting sun is diffracted off blowing dust rather than atmospheric molecules to create a visibly blue sunset.

"If you've ever stood downwind of a big forest fire and were looking at a sunset through the forest fire smoke, it sometimes has similar characteristics and you can see a bluish glow around the sun," said Lemmon.

And while cloudy skies meant there wasn't much to see from Southern California of Earth's moon's recent eclipse, JPL has also posted a video of a Martian eclipse.

In that footage, also compiled from images captured by Opportunity's cameras in early November, the Martian moon Phobos passes in front of the sun — due to the moon's small size, taking on an appearance more like a dime passing in front of a flashlight than the full-on eclipses we earthlings are used to seeing.

Though Phobos is actually several times closer to the surface of Mars than our moon is to earth, "if you set it down on Earth it wouldn't fill the L.A. basin," Lemmon said.

The Opportunity rover continues to travel the surface of Mars and now stands on the edge of Santa Maria Crater — about 90 meters wide and 10 meters deep, a significant discovery because it was created relatively recently in Mars history, unlike the ancient Victoria Crater that Opportunity first explored, said JPL Mars Rover engineer Bill Nelson.

Nelson said scientists hope to compare the mineral layers exposed in Victoria Crater to those at the Santa Maria Crater, looking for evidence of water-deposited clay that would revise estimates of the amount of liquid water once covering the surface of Mars.

"One of the key questions of our mission is to follow the water on Mars. We found a little bit, then we found Mars had more water than that. We're to the point that we know Mars at least had significant lakes, and now we're looking to establish whether Mars once had huge lakes or even inland seas," Nelson said.

By November 2011, Nelson expects Opportunity will have traversed another 6.5 kilometers from the Santa Maria Crater to an even larger formation called the Endeavor Crater.

The twin Mars rover Spirit, meanwhile, has remained incommunicado since it was forced to power down in anticipation of Martian winter while stuck for more than a year in a pit of loose Martian sand.

As summer approaches on Mars, JPL engineers are attempting to renew contact with Spirit, said Nelson.

The twin rovers were initially designed to last only three months, but completed that mission in April 2004, outlasting NASA's projected lifespan of about a year because favorable Martian winds continue to clean their power-drawing solar panels of accumulated dust.

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