This shot follows the cabin of a space elevator descending on a cable towards the northern parts of the Terra Cimmeria highlands on Mars. A large settlement, hinted as glowing lights in the dark, can be seen far below on the ground. One of Mars' two moons - Phobos - is seen above the cabin to the left of the cable in the beginning of the shot.
The space elevator is an idea that has been around for a long time, not only as science fiction but a serious suggestion of how to efficiently transfer large amounts of mass on and off a planet. The idea in short consists of a very long cable, along which cabins can climb up and down like an elevator. One end of the cable is attached to the ground at the planets equator, and the other to a counterweight beyond geostationary orbit. Geostationary orbit is an altitude where an object can stay stable in orbit over the exact same place above the ground and follow along as the planet revolves. In the case of the Earth that is at an altitude of about 36 thousand kilometers, so we are talking about a very long cable.
Although this concept is indeed a viable idea, it is also highly controversial when it comes to building one on Earth, and this may indeed turn out to be impossible due to the incredibly high demands on the strength of the cable in relation to its weight.
On smaller, lighter worlds, however, like the Moon or on Mars, the prospects for a future space elevator are somewhat more promising. As Mars' diameter is about half of the Earths, the elevator cable wouldn't have to be as long to reach geostationary orbit and due to the lighter gravitational pull it wouldn't suffer as much stress from its weight.
The texture for Mars in the shot comes from a tremendously high resolution assembly of NASA (and ESA?) orbital photographs made by John Van Vliet for the virtual space simulator Celestia
There is plenty of literature on space elevators online, but for an incredibly well researched incorporation of them (and Mars in general) in fiction I highly recommend the "Mars Trilogy" by Kim Stanley Robinson.
A small side note: As far as I have understood it, the ideal place to attach a space elevator on Mars would not be where I have done it in this shot, but on the top of the volcano Pavonis Mons. With a peak reaching 14 kilometers above Mars's mean surface level, and location almost exactly at the equator it would be the perfect spot - as it would cut a few kilometers from the length of the cable. However, the area around that mountain did not look as neat, so for purely artistic reasons I chose the Terra Cimmeria highlands instead.