https://www.jpl.nasa.gov/news/news.php?feature=6859

High-Silica 'Halos' Shed Light on Wet Ancient Mars
Jet Propulsion Laboratory
May 30, 2017

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

"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.

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 analyzed 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

News Media Contact
Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278
guy.webster@jpl.nasa.gov

Laura Mullane
Los Alamos National Laboratory, Los Alamos, N.M.
505-667-6012
mullane@lanl.gov

Laurie Cantillo / Dwayne Brown
NASA Headquarters, Washington
202-358-1077 / 202-358-1726
laura.l.cantillo@nasa.gov / dwayne.c.brown@nasa.gov

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