The towering
3-D features of Martian canyons and highlands are about to stand out like never
before, thanks to data from a high-resolution camera on the Mars Express orbiter.
These data,
collected by the camera on the European Space Agency's Mars
Express, are allowing scientists to create so-called Digital Terrain Models
(DTMs) to look around the Martian surface from different
directions and angles, as opposed to the usual bird's-eye view from above
provided by previous Mars orbiter cameras. The new data sets have now been
released on the Internet, the European Space Agency announced this week.
"Understanding
the topography of Mars is essential to understanding its geology," said Gerhard
Neukum, HRSC lead scientist at Freie Universität (FU) in Berlin, Germany.
Creating the
data for such digital models requires spacecraft to study the same Martian
feature at least twice, each time from a different angle. Most previous efforts
to do this have involved spacecraft making two orbital passes over features.
The Mars Express High Resolution Stereo Camera (HRSC) only
needs one overhead pass to capture images of a feature from three different
angles — on approach, directly underneath and receding into the distance. The
camera also obtains altitude measurements for its high-resolution images.
All that
data is processed by the German Space Agency (DLR) and FU Berlin for several
years before digital models of the Martian surface can start to emerge. Now researchers
are selecting the best data to "stitch them together" and develop digital
models on a "global scale," Fred Jansen, Mars Express senior manager,
told SPACE.com.
The newly
released DTMs allow researchers to instantly gauge the slope of hillsides or
the height of cliffs, as well as the altitude and slope of lava flows or desert
plains.
"This data
is essential for understanding how water or lava flowed across Mars," Neukum
said.
It also
helps planetary scientists better interpret Martian data from other instruments
and missions, such as the Mars
Advanced Radar for Subsurface and Ionosphere Sounding.
"Once we
know where the surface is, we can correctly interpret the radar echoes we get
from below it," said Angelo Rossi, HRSC scientist.
Lower
orbits of Mars Express allow for more detailed pictures. The Mars Express
mission will continue collecting such data until at least 2009.
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