05.15.2017 Putting Martian 'Tribulation' Behind
05.15.2017 From 'Tribulation' to 'Perseverance' on Mars
04.20.2017 Chemical Laptop Team
04.20.2017 Subcritical Water Extractor
04.20.2017 Chemical Laptop
04.20.2017 Atacama Landscape
03.30.2017 Measuring Mars' Atmosphere Loss
03.29.2017 Lifetime Achievement Award to Theisinger
03.29.2017 A Decade of Compiling the Sharpest Mars Map
03.21.2017 Break in Raised Tread on Curiosity Wheel
03.17.2017 COBALT/JPL team
03.09.2017 Back-to-Back Martian Dust Storms
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
02.08.2017 Mars Reconnaissance Orbiter Observes Changes
01.26.2017 Mono Lake
01.25.2017 'Wing' Dike of Hardened Lava in New Mexico
01.25.2017 Blade-Like Martian Walls Outline Polygons
01.23.2017 Spirit And Opportunity By The Numbers
01.10.2017 Mars 2020 Rover - Artist's Concept
01.06.2017 Earth and Its Moon, as Seen From Mars
12.13.2016 Now and Long Ago at Gale Crater, Mars
12.13.2016 Where's Boron? Mars Rover Detects It
11.15.2016 Schiaparelli Impact Site on Mars, Stereo
11.03.2016 Schiaparelli Impact Site on Mars, in Color
10.17.2016 MAVEN Captures Rapid Cloud Formation
10.17.2016 Mars' Nightside Atmosphere
10.17.2016 Ultraviolet Image Near Mars' South Pole
10.17.2016 Ultraviolet Mars Reveals Cloud Formation
10.05.2016 Dust Haze Hiding the Martian Surface in 2001
10.04.2016 Test of Lander Vision System for Mars 2020
10.03.2016 A Sharpened Ultraviolet View of Mars
10.03.2016 Curiosity Self-Portrait at 'Murray Buttes'
10.03.2016 Butte 'M9a' in 'Murray Buttes' on Mars
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