It was a clever way to bring attention to the craft, which has been at Mars since 2006 on what was originally supposed to be a two-year mission that has now been extended four times.

The orbiter has returned an incredible payload of insight into Mars' geologic history as well as evidence that liquid water flows on the surface. The amount of information returned is historic — more than that from all the other probes sent to planets added together.

And along the way, the spacecraft has made some amazing discoveries. Recently, for example, it discovered the site of the ill-fated Beagle 2 lander, which had been part of the European Space Agency's Mars Express mission in 2003 and went lost. Mars Reconnaissance Orbiter showed that the vehicle actually succeeded in landing softly enough on Mars on Dec. 25 that year to partially deploy its solar arrays.

The spacecraft has three cameras: a huge visual camera that can see great detail on the surface, a wide-angle camera and a color camera that is useful for monitoring dust storms and clouds. It also carries a sophisticated spectrometer that can determine the content of surface materials, a radiometer for measuring the atmosphere and a radar device for finding water beneath the surface.

The orbiter has been a significant factor in determining how much water is on Mars. Although the planet seems dusty and arid from most photographs, such as those sent back by the Curiosity rover, there is a lot of water ice on Mars. In 2009, the orbiter determined that there is almost 200,000 cubic miles of water ice near Mars' north pole. Radar onboard has determined that large aprons of debris near cliffs are probably ice glaciers covered by dust. Large areas of chloride deposits detected by the orbiter indicate that large seas and lakes once covered parts of Mars.