In a spectacular video released to the Web on the seventh launch anniversary of Mars Express, the "Mars Webcam" has captured an astronaut's eye view of one complete orbit around the Red Planet. Volcanoes, canyons, polar caps, and one of Mars' moons march through the view as the spacecraft sweeps its elliptical path in space around Mars.
What do we see in the video? As it starts, the Tharsis Montes are on display: Ascraeus, Pavonis, and Arsia Montes in a line, with Olympus Mons above. Mars Express is near apoapsis, so is traveling very slowly in its orbit, which permits it to see the rotation of Mars and new terrain coming into the daylight. But as Mars Express proceeds in its orbit, it travels faster and faster, plunging past Mars' night side. As it recedes again and returns to daylight, the Martian surface fills the view, the spacecraft's relatively rapid motion causing it to pass by quickly. The swirls of ice that make up the summer-sunlit north polar cap swing by. Finally, at the very end, a dark spot speeds from top to bottom across the video -- that's Phobos zipping past on its own orbit. Wow.
Here's another version of the video, showing the relative positions of Mars Express and Mars.
At apoapsis, Mars Express was 10,527 kilometers from Mars' surface; at closest approach, it was only 358 kilometers from the ground.
There were 600 images in the observation, alternating between two different exposure settings; the video seems to have been made from the longer-exposure images, so some parts of the planet's disk are saturated.
The images were taken on Mars Express' 8,194th orbit, May 27, 2010 between 02:00 and 09:00 UTC (03:00-10:00 CEST) and were transmitted to Earth a few hours later via ESA's 35 m-diameter New Norcia deep space antenna in Australia.
he "Mars Webcam" is actually the Visual Monitoring Camera or VMC. VMC is an engineering camera on Mars Express whose purpose was to document the departure of the ill-fated Beagle 2, and following the Beagle 2 deployment it wasn't used for years. In 2008, though, ESA brought it back online, because although it is a very low-quality camera (compared to the science cameras like HRSC and HiRISE), it has a unique capability to take full-globe shots of Mars, the only camera at Mars currently capable of doing so.
ESA didn't have many resources to devote to this camera. So, in an innovative (and cheap) move, they (by which I mean Thomas Ormston, a worker in ESA operations) tossed all the raw images from this camera into a blog on the ESA website and invited the public to do their best with the images. The public rose to the challenge. In particular, Gordan Ugarkovic, an amateur image processor whose work I've featured here numerous times in the past, developed a piece of command-line software called vmc2rgb that was able to convert the raw image data to color images. Ormston, in turn, incorporated vmc2rgb into his data posting workflow, so now the raw images as posted on the Web (here and here) are in beautiful color.