Although NASA didn't give up on the Spirit rover until last month, scientists last heard from the robot explorer in March 2010, when it went silent at the onset of the cold and dark Martian winter.

Assembled by Dr. Ken Kremer and Marco Di Lorenzo from publicly-available NASA imagery, these mosaics show Spirit's final resting place in vivid color. A final single frame image from Spirit's panoramic camera was one of the final snapshots the rover sent back to Earth in March 2010.

After blasting off from Earth in 2003, Spirit reached the Red Planet seven months later. Greatly surpassing its three-month mission goal, Spirit operated for more than six years before going into hibernation last year.

Scientists hoped the rover would survive another Martian winter and continue returning data as a stationary research station. Officials blame its death on the rover being stuck in a stubborn sand trap, and the situation was exacerbated by two broken wheels.

In the end, Spirit wasn't able to limp out of its predicament and spent the winter with its dusty solar panels pointed away from the sun as temperatures plummeted lower than the craft had ever experienced before.

The images below are some of Spirit's final photographic contributions to the Martian science record. But researchers say the rover's data will continue being analyzed and will yield important insights for years to come.

Spirit collected this mosaic in April 2009 as it approached a steep mound named "Von Braun" atop a modest plateau known as "Home Plate" on Sol 1869. Photo credit: Ken Kremer/Marco Di Lorenzo/NASA/JPL/Cornell   This mosaic was assembled from imagery taken on Sol 2174 in February 2010. It shows Spirit's robot arm hovering over bits of light-colored Martian soil excavated as the rover spun its wheels in a fruitless attempt to pull itself out of a sand trap. Photo credit: Ken Kremer/Marco Di Lorenzo/NASA/JPL/Cornell   This was Spirit's last panorama taken before the rover succumbed to its fourth winter on Mars. It shows the Columbia Hills as viewed from the rover's final resting place, a location dubbed "Troy" by scientists. Photo credit: Ken Kremer/Marco Di Lorenzo/NASA/JPL/Cornell   This false color mosaic was assembled from frames taken by Spirit's microscopic imager under the rover's belly in June 2009. Photo credit: Ken Kremer/Marco Di Lorenzo/NASA/JPL/Cornell   In one of its last images, Spirit's panoramic camera looked down to snap a black-and-white picture of the clumpy Martian soil and one of the rover's stuck wheels. Photo credit: NASA/JPL/Cornell