Ben Shoemate's Notebook

NASA's prolific Mars Reconnaissance Orbiter turns five Earth years old Thursday.

Since settling into orbit around the Red Planet on March 10, 2006, MRO has transmitted more data to Earth -- 131 trillion bits and more than 70,000 images so far -- than all other interplanetary missions combined.

After the orbiter finished all its initial science objectives in the first two years, NASA extended its lifetime twice. The extra time let MRO watch Mars change over two-and-a-half Martian years, giving a new picture of a shifting, dynamic planet.

"Each Mars year is unique, and additional coverage gives us a better chance to understand the nature of changes in the atmosphere and on the surface," said Rich Zurek of NASA's Jet Propulsion Lab in a press release. "We have already learned that Mars is a more dynamic and diverse planet than what we knew five years ago. We continue to see new things."

MRO carries six science instruments, including radar that peels back the layers of the Martian surface, a spectrometer that has mapped the mineral content of three-quarters of the planet, and a weather camera that monitors clouds and dust storms.

But the show stopper is the HiRise camera (High Resolution Imaging Science Experiment), which can resolve features the size of a beach ball from 180 miles away.

To date, HiRise has snapped more than 18,500 close ups of Mars' canyons, craters and dunes. In honor of MRO's fifth birthday, here are some of our favorites.

Above:

Dust-Devil Tattoo

These twisty trails were traced by dust devils, spinning columns of rising air that pick up loose red dust grains and reveal darker, heavier sand beneath. Dust devils have been blamed for unexpectedly cleaning off the Mars rovers' solar panels. This image was taken Aug. 24, 2009.