12h 42min, apr 7, 2001 y - 2001 Mars Odyssey
Currently in orbit at Mars (NASA)
Mars Odyssey is capturing images of the Martian surface at resolutions between those of Viking and Mars Global Surveyor, and is making both daytime and nighttime observations of the surface in thermal infrared wavelengths at resolutions higher than ever before. It has detected massive deposits of water lying below Mars’ surface in near-polar regions and widespread deposits of olivine across the planet, indicating a dry past for Mars. The MARIE instrument measured the radiation environment at Mars to determine its potential impact on human explorers, and found them to be 2 to 3 times higher than expected. Odyssey also serves as a communications relay for the Opportunity and Curiosity rovers.
Added to timeline:
the videos are in the parts of Mars Exploration Rover Spirit...