Multimedia
* Living
Space
Seeing Mars
in the Data
Almost weekly there are new astounding
pictures made by the Mars
Global Explorer (MGL) and the newly arrived Space
Odyssey 2000 orbiters.
In addition to the cameras, there
is another important tool on the MGL called the Mars
Orbiter Laser Altimeter (MOLA). This experiment measured
the altitude of the Mars surface by firing infrared laser
pluses ten times a second and counting the time till the reflected
light appeared. Before the instrument malfunctioned in the
summer of 2001, it had made measurements in most regions of
the planet.
A data set of 340 million points
has been released. The vertical accuracy is about 5m and the
horizontal spatial accuracy is about 100m.
The
Planet 3D project created by the programmer Adrian Lark
provides graphics software that allows users to take the MOLA
data and obtain 3D views of the surface.
Note that going from the raw
altitude data to a realistic looking view from a chosen spot
on the surfact requires some artistic license, e.g. chosing
the surface textures, time of day, etc.
Also, the distance
traversed between each point is 330m, so some algorithm must
be used to extrapolate in some reasonable manner between the
points, even though in reality there could be large hills
or deep ravines in betweeen.
Nevertheless, the results can
be quite realistic and very spectacular. See, for example,
the beautiful views as might be seen from different vistas
on the Valles Marineris at Valles
Marineris réalisées par Adrian Lark.
Viewers are available for download
that allow one to view images of various regions of Mars.
(There are also viewers for Earth and Venus using similar
data.)
The Mars Explorer program allows
one to move along the surface and see a full 3D panoramic
view.
Also, screensavers, wallpaper,
animations, and maps are avalable for free downloads.
[Ancient
Mars: Renderings Show Raging Floods, Vast Oceans - Space.com
- Jan.4.02]
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