Lava likely made river-like meandering channel on Mars

March 5th, 2010 - 3:40 pm ICT by ANI  

Washington, March 5 (ANI): New research indicates that flowing lava can carve or build paths very much like the riverbeds and canyons etched by water, which probably explains at least one of the meandering channels on the surface of Mars.

Whether channels on Mars were formed by water or by lava has been debated for years, and the outcome is thought to influence the likelihood of finding life there.

“To understand if life, as we know it, ever existed on Mars, we need to understand where water is or was,” said Jacob Bleacher at NASA’s Goddard Space Flight Center, Greenbelt, Maryland.

Geologists think that the water currently on the surface of Mars is either held in the soil or takes the form of ice at the planet’s north and south poles.

But, some researchers contend that water flowed or pooled on the surface sometime in the past.

Water in this form is thought to increase the chance of some form of past or present life.

Bleacher and his colleagues carried out a careful study of a single channel on the southwest flank of Mars’ Ascraeus Mons volcano, one of the three clustered volcanoes collectively called the Tharsis Montes.

To piece together images covering more than 270 kilometers of this channel, the team relied on high-resolution pictures from three cameras-the Thermal Emission Imaging System (THEMIS), the Context Imager (CTX) and the High/Super Resolution Stereo Color (HRSC) imager-as well as earlier data from the Mars Orbiter Laser Altimeter (MOLA).

Because the fluid that formed this and other Ascraeus Mons channels is long-gone, its identity has been hard to deduce, but the visual clues at the source of the channel seem to point to water.

These clues include small islands, secondary channels that branch off and rejoin the main one and eroded bars on the insides of the curves of the channels.

But at the channel’s other end, an area not clearly seen before, Bleacher and colleagues found a ridge that appears to have lava flows coming out of it.

In some areas, “the channel is actually roofed over, as if it were a lava tube, and lined up along this, we see several rootless vents,” or openings where lava is forced out of the tube and creates small structures, explained Bleacher.

These types of features don’t form in water-carved channels, he noted.

Bleacher said that having one end of the channel formed by water and the other end by lava is an “exotic” combination.

According to him, more likely, the entire channel was formed by lava. (ANI)

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