Mars reveals itself in 3D
A new high-resolution Digital Terrain Model data set of Mars has been released on to the Internet, allowing researchers to obtain new information about the Red Planet in 3D
Courtesy of data gathered by the Mars Express High Resolution Stereo Camera (HRSC), this Digital Terrain Model (DTM) will allow scientists to 'stand' on the planet's surface.
Although ordinary images can provide bird's-eye views, they don't capture the topography and the vertical elevation of the surroundings. The HRSC was specially designed to provide such information and, after years of specialised data processing, the first comprehensive release of 3D data of a large part of the martian surface is now ready.
"Understanding the topography of Mars is essential to understanding its geology," says Prof. Gerhard Neukum, Freie Universität (FU) Berlin, Germany, Principal Investigator for the HRSC.
The DTM can instantly tell researchers the slope of hillsides or the height of cliffs, the altitude and slope of lava flows or desert plains. "This data is essential for understanding how water or lava flowed across Mars," says Neukum.
The Mars Express DTM is the most detailed topographic data set ever released for the Red Planet. Its release has been made possible by processing individual image swaths taken by the HRSC as Mars Express sweeps through its orbit. The individual swaths are then put together into mosaics that cover large regions.
The orbit of Mars Express determines the resolution of its pictures. When it is closest to the surface, it can take the most detailed pictures. "As the mission continues, we are gradually filling in the gaps and collecting high-resolution data whenever possible," says Neukum.
The team plans to add more data to the DTMs to extend the surface coverage as Mars Express continues its mission until at least 2009 and HRSC continues its scrutiny of the planet.
Constructing a Digital Terrain Model requires a spacecraft to look at the same surface feature twice, each time from a different angle. The High Resolution Stereo Camera (HRSC) on Mars Express is the only experiment that can do it in one pass.
To achieve its complementary views, HRSC has nine individual scan lines that point fore, aft and straight down. Therefore, it is able to see a feature coming, observe it directly from above and also watch it recede into the distance, providing all the different angles needed.
HRSC provides altitude data for every data point the camera sees. It is the first time that high-resolution images have been accompanied by high-resolution topography.
Image: Olympus Mons on Mars, recreated in 3D from the HRSC data