[meteorite-list] Curiosity Mars Rover Checks Odd-looking Iron Meteorite

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?feature=6667

Curiosity Mars Rover Checks Odd-looking Iron Meteorite
Jet Propulsion Laboratory
November 2, 2016

[Image]
The dark, golf-ball-size object in this composite, colorized view from 
the ChemCam instrument on NASA's Curiosity Mars rover is a nickel-iron 
meteorite, as confirmed by analysis using laser pulses from ChemCam on 
Oct. 30, 2016. The grid of bright spots on the rock resulted from the 
laser pulses. 
Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS/MSSS

Laser-zapping of a globular, golf-ball-size object on Mars by NASA's Curiosity 
rover confirms that it is an iron-nickel meteorite fallen from the Red 
Planet's sky.

Iron-nickel meteorites are a common class of space rocks found on Earth, 
and previous examples have been seen on Mars, but this one, called "Egg 
Rock," is the first on Mars examined with a laser-firing spectrometer. 
To do so, the rover team used Curiosity's Chemistry and Camera (ChemCam) 
instrument.

Scientists of the Mars Science Laboratory (MSL) project, which operates 
the rover, first noticed the odd-looking rock in images taken by Curiosity's 
Mast Camera (Mastcam) at a site the rover reached by an Oct. 27 drive.

"The dark, smooth and lustrous aspect of this target, and its sort of 
spherical shape attracted the attention of some MSL scientists when we 
received the Mastcam images at the new location," said ChemCam team member 
Pierre-Yves Meslin, at the Research Institute in Astrophysics and Planetology 
(IRAP), of France's National Center for Scientific Research (CNRS) and 
the University of Toulouse, France.

ChemCam found iron, nickel and phosphorus, plus lesser ingredients, in 
concentrations still being determined through analysis of the spectrum 
of light produced from dozens of laser pulses at nine spots on the object. 
The enrichment in both nickel and phosphorus at some of the same points 
suggests the presence of an iron-nickel-phosphide mineral that is rare 
except in iron-nickel meteorites, Meslin said.

Iron meteorites typically originate as core material of asteroids that 
melt, allowing the molten metal fraction of the asteroid's composition 
to sink to the center and form a core.

"Iron meteorites provide records of many different asteroids that broke 
up, with fragments of their cores ending up on Earth and on Mars," said 
ChemCam team member Horton Newsom of the University of New Mexico, Albuquerque. 
"Mars may have sampled a different population of asteroids than Earth 
has."

In addition, the study of iron meteorites found on Mars -- including examples 
found previously by Mars rovers -- can provide information about how long 
exposure to the Martian environment has affected them, in comparison with 
how Earth's environment affects iron meteorites. Egg Rock may have fallen 
to the surface of Mars many millions of years ago. Researchers will be 
analyzing the ChemCam data from the first few laser shots at each target 
point and data from subsequent shots at the same point, to compare surface 
versus interior chemistry.

Egg Rock was found along the rover's path up a layer of lower Mount Sharp 
called the Murray formation, where sedimentary rocks hold records of ancient 
lakebed environments on Mars. The main science goal for Curiosity's second 
extended mission, which began last month, is to investigate how ancient 
environmental conditions changed over time. The mission has already determined 
that this region once offered conditons favorable for microbial life, 
if any life ever existed on Mars.

Curiosity was launched five years ago this month, on Nov. 26, 2011, from 
Cape Canaveral Air Force Station, Florida. It landed inside Gale Crater, 
near the foot of Mount Sharp, in August 2012.

The rover remains in good condition for continuing its investigations, 
after working more than twice as long as its originally planned prime 
mission of about 23 months, though two of its 10 science instruments have 
recently shown signs of potentially reduced capability. The neutron-generating 
component of Curiosity's Dynamic Albedo of Neutrons (DAN) instrument, 
designed for working through the prime mission, is returning data showing 
reduced voltage. Even if DAN could no longer generate neutrons, the instrument 
could continue to check for water molecules in the ground by using its 
passive mode. The performance of the wind-sensing capability from Curiosity's 
Rover Environmental Monitoring Station (REMS) is also changing, though 
that instrument still returns other Mars-weather data daily, such as temperatures, 
humidity and pressure. Analysis is in progress for fuller diagnosis of 
unusual data from DAN, which was provided by Russia, and REMS, provided 
by Spain.

The U.S. Department of Energy's Los Alamos National Laboratory in Los 
Alamos, New Mexico, developed ChemCam in partnership with scientists and 
engineers funded by the French national space agency (CNES). Mastcam was 
built by Malin Space Science Systems, San Diego. NASA's Jet Propulsion 
Laboratory, a division of Caltech in Pasadena, California, manages the 
Mars Science Laboratory Project for the NASA Science Mission Directorate, 
Washington, and built the project's Curiosity rover. For more information 
about Curiosity, visit:

http://mars.jpl.nasa.gov/msl

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

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

2016-287