The Other Active Mars Rover

4 January 2013 by Troy McConaghy, posted in Astronomy, Uncategorized

The Curiosity rover got a lot of attention when it landed on Mars this past August. And it should have! It's the size of a car and was lowered to the Martian ground by a hovering, rocket-lofted skycrane. Curiosity has been driving around and sending back loads of data ever since.

But there's another rover plying the dusty regolith of Mars…

Three Mars Rovers

Life-size models of Spirit/Opportunity, Sojurner and Curiosity (left to right)


NASA has landed four rovers on Mars:

Sojurner landed with a base station that stayed put while it drove around. It talked to Earth via the base station. When the base station stopped communicating, Sojurner was cut off from Earth, even though it was still working. As a result, nobody knows (for sure) where Sojurner is today.

Spirit explored Mars for many years, but it got stuck in soft ground in May 2009, and never got unstuck. (It had gotten stuck before, but not permanently.) Spirit's last communication with Earth was in March 2010.

Like a toy rabbit in a battery commercial, Opportunity keeps on going. Its original mission was 90 Martian days or "sols" (i.e. about 92 Earth days, or 0.25 years). It has now been operating on Mars for over 8 years!

There were some close calls. It got stuck in a sand dune for over a month in 2005. (Mission planners called it "Purgatory Dune.") There were problems with the robotic arm since the beginning. In 2007, big dust storms arose and blocked the sun (which powers the rover via solar panels); there was the possibility that the batteries would go dead. But they didn't.

Below is one of the latest images sent to Earth by Opportunity.

Small spherical objects spotted by Opportunity

Small spherical objects spotted by Opportunity


"This is one of the most extraordinary pictures from the whole mission," said Opportunity's principal investigator, Steve Squyres (a professor of Astronomy at Cornell University). "…we have a wonderful geological puzzle in front of us." They still aren't sure what the small spherical objects are. I know one thing: Opportunity has been an amazing rover.


[1] Squyres, Steve. Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet. Hyperion, 2006.

[2] JPL's Mars Exploration Rovers Mission home page.

Image Sources

All images are courtesy of NASA (and are public domain). Image credit for the image of small spherical objects: NASA/JPL-Caltech/Cornell Univ./ USGS/Modesto Junior College.

About this Blog

Outer Spacing is a blog about space exploration and development. It's written by Troy McConaghy (@TroyMc on Twitter).


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