High-silica 'halos' shed light on wet ancient Mars

Posted by pt91 at May 31, 2017 04:42 PM |
University of Leicester scientists help to analyse data from NASA’s Curiosity Mars rover

Issued by University of Leicester Press Office on 31 May 2017

Image from NASA’s Curiosity Mars rover available at: https://www.jpl.nasa.gov/news/news.php?release=2017-154

Pale "halos" around fractures in bedrock analysed by NASA's Curiosity Mars rover contain copious silica, indicating that ancient Mars had liquid water for a long time.

University of Leicester scientists are part of the science teams that gathered and analysed data from the rover’s ChemCam.

Professor John Bridges, Professor of Planetary Science in the University of Leicester Department of Physics and Astronomy, said: “The UK team worked in the science teams that gathered and analysed the ChemCam data. This is the laser that we shoot at the rocks in Gale Crater, with the resultant light emission being used to calculate the chemical composition.

“Most samples on Mars have basaltic compositions but here we found high silica enrichments which resulted from an input from a high silica volcanic source followed by burial and remobilisation of opal-like deposits. We are following up this work to determine what are the source compositions that fed sediments into Gale Crater to better understand how the Mars crust evolved and provided potential habitats for life.”

"The concentration of silica is very high at the centerlines of these halos," said Jens Frydenvang, a rover-team scientist at Los Alamos National Laboratory in New Mexico, and the University of Copenhagen in Denmark. "What we’re seeing is that silica appears to have migrated between very old sedimentary bedrock and into younger overlying rocks."

Frydenvang is the lead author of a report about these findings published in Geophysical Research Letters, which the University of Leicester scientists are co-authors of.

NASA landed Curiosity on Mars in 2012 with a goal to determine whether Mars ever offered environmental conditions favorable for microbial life. The mission "has been very successful in showing that Gale Crater once held a lake with water that we would even have been able to drink from, but we still don’t know how long this habitable environment endured," he said. "What this finding tells us is that, even when the lake eventually evaporated, substantial amounts of groundwater were present for longer than we previously thought -- further expanding the window for when life might have existed on Mars."

For more information about the newly published report, visit: http://bit.ly/2r8dyOF

The halos were first analysed in 2015 with Curiosity's science-instrument payload, including the laser-shooting Chemistry and Camera (ChemCam) instrument, which was developed at Los Alamos National Laboratory in conjunction with the French space agency. The rover has subsequently explored higher and younger layers of lower Mount Sharp, investigating how ancient environmental conditions changed.

NASA's two active Mars rovers and three Mars orbiters are all part of ambitious robotic exploration to understand Mars, which helps lead the way for sending humans to Mars in the 2030s. The Curiosity mission is managed by NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, for NASA's Science Mission Directorate, Washington. For more about Curiosity, visit: http://www.nasa.gov/curiosity

-end-

Notes to editors:

Professor John Bridges

University of Leicester

j.bridges@le.ac.uk

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Laura Mullane
Los Alamos National Laboratory, Los Alamos, N.M.
mullane@lanl.gov

Laurie Cantillo / Dwayne Brown
NASA Headquarters, Washington
laura.l.cantillo@nasa.gov / dwayne.c.brown@nasa.gov

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