Warm weather near the Martian equator may have melted the ice in ice-rich soils as recently as 2 million years ago, according to a paper published yesterday in “Earth and Planetary Science Letters.” This indicates that the Red Planet was warmer and more life-friendly much later in its history than previous studies show.

Matthew Balme, a research scientist with the Tucson-based Planetary Science Institute and a research fellow at the United Kingdom’s Open University, discovered signs of melting permafrost in images from NASA’s HiRISE (High Resolution Imaging Science Experiment) camera, which is flying aboard the Mars Reconnaissance Orbiter.

The images show that landforms once thought to be shaped by volcanism were actually modified by the expansion and contraction of ice due to freeze/thaw cycles, Balme said.

Balme studied an outflow channel that was active as recently as 2 to 8 million years ago. The channel contains polygonal patterns, branched channels, blocky debris and mound/cone formations, all of which are similar to formations found where permafrost melts on Earth.

“These observations demonstrate that ice melted near the Martian equator within the past few million years and then refroze,” Balme said. “This probably happened over many freeze/thaw cycles.”

Since liquid water is essential to life as we know it, this equatorial channel would be an ideal place to hunt for traces of past or present Martian life, Balme added.

Balme’s research was funded by the UK’s Science and Technology Facilities Council and by NASA’s Mars Data Analysis Program. In addition to his post with PSI, Balme is an Aurora Fellow at the UK’s Open University.

Science Contact:

Matt Balme
Research Scientist
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mbalme@psi.edu

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Director
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sykes@psi.edu

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The Planetary Science Institute is a private, nonprofit 501(c)(3) corporation dedicated to solar system exploration. It is headquartered in Tucson, Arizona, where it was founded in 1972.

PSI scientists are involved in numerous NASA and international missions, the study of Mars and other planets, the Moon, asteroids, comets, interplanetary dust, impact physics, the origin of the solar system, extra-solar planet formation, dynamics, the rise of life, and other areas of research. They conduct fieldwork in North America, Australia and Africa. They also are actively involved in science education and public outreach through school programs, children’s books, popular science books and art.

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