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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
Russian Hydrogen-Checking Instrument on Curiosity Fires 2 Millionth PulseThe Russian-made instrument on NASA's Mars rover Curiosity for detecting water that is adsorbed into soil or bound into shallow underground minerals has fired its 2 millionth pulse of energetic neutrons into the ground. It reached this milestone in late January 2014, not quite 18 months after the rover's landing on Mars in early August 2012.
Each pulse into the ground lasts about one microsecond. The instrument, Dynamic Albedo of Neutrons (DAN), measures the flow of neutrons with different energy levels returning from the ground, and their delay times, as an indication of the amount and depth of hydrogen in the ground beneath the rover. Any detected hydrogen would most likely be in the form of water.
This graph shows the cumulative total of pulses from DAN's pulsing neutron generator (PNG) rising to the 2 million level (vertical axis) as time progressed from the start of the mission. The top horizontal axis is labeled by Earth dates; the bottom one by the number of sols (Martian days) into the mission.
Each pulse DAN fires includes approximately 10 million high-energy neutrons, so the total number of neutrons fired by the device on Mars is about 20,000,000,000,000. That is about one-fifth of DAN's supply of these "bullets" for use during Curiosity's investigations on Mars.
DAN detects water down to about 2 feet (60 centimeters) deep. During the rover's investigations so far, data from DAN have enabled researchers to calculate that an upper portion of that zone averages about 1.5 percent water content, by weight, and a deeper portion averages about twice as much. The amount of water has varied slightly along the route.
Russia's Space Research Institute developed DAN in close cooperation with the N.L. Dukhov All-Russia Research Institute of Automatics, Moscow, and the Joint Institute for Nuclear Research, Dubna.
Image Credit: NASA/JPL-Caltech/Russian Space Research Institute