It’s
not the work of fastidious Face on
Mars engineers – but there’s a natural bridge on the red planet.
A
new batch of NASA Mars Reconnaissance
Orbiter (MRO) imagery includes this inspection of the Tartarus Colles
region.
MRO’s
High-Resolution
Imaging Science Experiment (HiRISE) camera has viewed a narrow trough
running down the center of a valley that lies between two hills. Two trough
segments terminate in blunt ends that are separated by a natural bridge or wall
of material 75 feet (23 meters) wide.
It
is likely that this trough formed as a lava
tube and that its roof has mostly caved in over time, leaving only a small
section standing.
Lava
tubes are created when the top and sides of a “river” of lava freeze while
molten rock continues to flow through its interior. After the eruption ceases,
molten lava flows out of the tube leaving it empty. Tubes require a steady and
sustained flow of lava to form, and they allow the lava to be transported a
considerable distance without losing too much heat.
MRO’s
super-powerful HiRISE images like this one are helpful in deciphering the
various types of volcanism that have taken place on Mars.
-- Leonard David
Credit:
NASA/JPL-Caltech/University of Arizona
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