[meteorite-list] Curiosity Mars Rover Sees Trend in Water Presence

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 18 Mar 2013 10:36:45 -0700 (PDT)
Message-ID: <201303181736.r2IHajGs029662_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?release=2013-099

Curiosity Mars Rover Sees Trend in Water Presence
Jet Propulsion Laboratory
March 18, 2013

  Images
    * Hydration Map, Based on Mastcam Spectra, for 'Knorr' Rock Target <#1>
    * Rock Target 'Knorr' Near Curiosity in Rover's Self-Portrait <#2>
    * Target 'Wernecke' After Brushing by Curiosity <#3>
    * Elemental Compositions of 'Yellowknife Bay' Rocks <#4>
    * Veins and Nodules at 'Knorr' Target in 'Yellowknife Bay' of Gale
      Crater <#5>
    * Indication of Hydration in Veins and Nodules of 'Knorr' in
      'Yellowknife Bay' <#6>
    * Rock 'Tintina' Exposes 'Yellowknife Bay' Vein Material <#7>
    * Hydration Map, Based on Mastcam Spectra, for broken rock 'Tintina'
      <#8>
    * Close-up View of Broken Mars Rock 'Tintina' <#9>
    * Mast Camera and Its Calibration Target on Curiosity Rover <#10>
    * Filters for Color Imaging and for Science <#11>
    * 'Raw,' 'Natural' and 'White-Balanced' Views of Martian Terrain <#12>
    * Using Curiosity's Mast Camera to View Scene in 'Natural' Color <#13>
    * Using False Color from Curiosity's Mast Camera <#14>
    * Bluish-Black Rock with White 'Crystals' on Mars <#15>

THE WOODLANDS, Texas - NASA's Mars rover Curiosity has seen evidence of
water-bearing minerals in rocks near where it had already found clay
minerals inside a drilled rock.

Last week, the rover's science team announced that analysis of powder
from a drilled mudstone rock on Mars indicates past environmental
conditions that were favorable for microbial life. Additional findings
presented today (March 18) at a news briefing at the Lunar and Planetary
Science Conference in The Woodlands, Texas, suggest those conditions
extended beyond the site of the drilling.

Using infrared-imaging capability of a camera on the rover and an
instrument that shoots neutrons into the ground to probe for hydrogen,
researchers have found more hydration of minerals near the clay-bearing
rock than at locations Curiosity visited earlier.

The rover's Mast Camera (Mastcam) can also serve as a mineral-detecting
and hydration-detecting tool, reported Jim Bell of Arizona State
University, Tempe. "Some iron-bearing rocks and minerals can be detected
and mapped using the Mastcam's near-infrared filters."

Ratios of brightness in different Mastcam near-infrared wavelengths can
indicate the presence of some hydrated minerals. The technique was used
to check rocks in the "Yellowknife Bay" area where Curiosity's drill
last month collected the first powder from the interior of a rock on
Mars. Some rocks in Yellowknife Bay are crisscrossed with bright veins.

"With Mastcam, we see elevated hydration signals in the narrow veins
that cut many of the rocks in this area," said Melissa Rice of the
California Institute of Technology, Pasadena. "These bright veins
contain hydrated minerals that are different from the clay minerals in
the surrounding rock matrix."

The Russian-made Dynamic Albedo of Neutrons (DAN) instrument on
Curiosity detects hydrogen beneath the rover. At the rover's very dry
study area on Mars, the detected hydrogen is mainly in water molecules
bound into minerals. "We definitely see signal variation along the
traverse from the landing point to Yellowknife Bay," said DAN Deputy
Principal Investigator Maxim Litvak of the Space Research Institute,
Moscow. "More water is detected at Yellowknife Bay than earlier on the
route. Even within Yellowknife Bay, we see significant variation."

Findings presented today from the Canadian-made Alpha Particle X-ray
Spectrometer (APXS) on Curiosity's arm indicate that the wet
environmental processes that produced clay at Yellowknife Bay did so
without much change in the overall mix of chemical elements present. The
elemental composition of the outcrop Curiosity drilled into matches the
composition of basalt. For example, it has basalt-like proportions of
silicon, aluminum, magnesium and iron. Basalt is the most common rock
type on Mars. It is igneous, but it is also thought to be the parent
material for sedimentary rocks Curiosity has examined.

"The elemental composition of rocks in Yellowknife Bay wasn't changed
much by mineral alteration," said Curiosity science team member Mariek
Schmidt of Brock University, Saint Catharines, Ontario, Canada.

A dust coating on rocks had made the composition detected by APXS not
quite a match for basalt until Curiosity used a brush to sweep the dust
away. After that, APXS saw less sulfur.

"By removing the dust, we've got a better reading that pushes the
classification toward basaltic composition," Schmidt said. The
sedimentary rocks at Yellowknife Bay likely formed when original
basaltic rocks were broken into fragments, transported, re-deposited as
sedimentary particles, and mineralogically altered by exposure to water.

NASA's Mars Science Laboratory Project is using Curiosity to investigate
whether an area within Mars' Gale Crater has ever offered an environment
favorable for microbial life. Curiosity, carrying 10 science
instruments, landed seven months ago to begin its two-year prime
mission. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the
project for NASA's Science Mission Directorate in Washington.

For more about the mission, visit: http://www.jpl.nasa.gov/msl ,
http://marsprogram.jpl.nasa.gov/msl and http://www.nasa.gov/msl .

You can follow the mission on Facebook and Twitter at:
http://www.facebook.com/marscuriosity and
http://www.twitter.com/marscuriosity .

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown at nasa.gov

2013-099
Received on Mon 18 Mar 2013 01:36:45 PM PDT