03.21.2017 Break in Raised Tread on Curiosity Wheel
02.27.2017 Swirling Dust in Gale Crater, Mars, Sol 1613
02.27.2017 Dust Devil Passes Near Martian Sand Dune
02.27.2017 Sand Moving Under Curiosity, One Day to Next
12.13.2016 Now and Long Ago at Gale Crater, Mars
12.13.2016 Where's Boron? Mars Rover Detects It
10.03.2016 Curiosity Self-Portrait at 'Murray Buttes'
10.03.2016 Butte 'M9a' in 'Murray Buttes' on Mars
09.19.2016 Ribbon Cutting
09.09.2016 Farewell to Murray Buttes (Image 5)
09.09.2016 Farewell to Murray Buttes (Image 4)
09.09.2016 Farewell to Murray Buttes (Image 3)
09.09.2016 Farewell to Murray Buttes (Image 2)
09.09.2016 Farewell to Murray Buttes (Image 1)
08.26.2016 Out-of-this-World Records
03.30.2016 Erisa Hines
03.30.2016 Buzz Aldrin
02.12.2016 Women in Science
02.09.2016 Adam Steltzner, a JPL engineer
01.27.2016 Night Close-up of Martian Sand Grains
01.27.2016 Curiosity Self-Portrait at Martian Sand Dune
12.17.2015 Alteration Effects at Gale and Gusev Craters
12.17.2015 Full-Circle View Near 'Marias Pass' on Mars
12.11.2015 Surface Close-up of a Martian Sand Dune
12.11.2015 Martian Sand Disturbed by Rover Wheel
Isotopic Clues to Mars' Crust-Atmosphere InteractionsChemistry that takes place in the surface material on Mars can explain why particular xenon (Xe) and krypton (Kr) isotopes are more abundant in the Martian atmosphere than expected.
The isotopes -- variants that have different numbers of neutrons -- are formed in the loose rocks and material that make up the regolith -- the surface layer down to solid rock. The chemistry begins when cosmic rays penetrate into the surface material. If the cosmic rays strike an atom of barium (Ba), the barium can lose one or more of its neutrons (n0). Atoms of xenon can pick up some of those neutrons – a process called neutron capture – to form the isotopes xenon-124 and xenon-126. In the same way, atoms of bromine (Br) can lose some of their neutrons to krypton, leading to the formation of krypton-80 and krypton-82 isotopes. These isotopes can enter the atmosphere when the regolith is disturbed by impacts and abrasion, allowing gas to escape.
The Sample Analysis at Mars (SAM) laboratory suite inside NASA's Curiosity Mars rover has measured the isotope ratios of xenon and krypton in Mars' atmosphere. Development of SAM was coordinated by NASA's Goddard Space Flight Center, Greenbelt, Maryland. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Science Laboratory Project, and built the project's Curiosity rover, for NASA's Science Mission Directorate, Washington.
Image Credit: NASA/GSFC/JPL-Caltech
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