12.19.2016 Curiosity Rover's Location for Sol 1553
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
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
08.04.2016 Mars Rover Is New Social Media Game
08.04.2016 Mars Rover Social Media Game
08.02.2016 Artist Concept for RIMFAX
07.20.2016 Viking 40 Year Anniversary Artwork: Medal
07.18.2016 Mars 2020 Range Trigger
07.14.2016 NASA to Launch Mars Rover in 2020
Curiosity Blasts Ground with NeutronsNASA's Curiosity rover pinged the ground with neutrons for the first time, a process called active neutron sounding, on Aug. 17, 2012. The instrument involved, called the Dynamic Albedo of Neutrons, or DAN, measures the amount of hydrogen -- an indicator of water -- in soil by observing the degree to which neutrons are scattered.
The red time profile shows neutrons that were emitted from the ground below Curiosity after the instrument's pulsing neutron generator hit the ground with pulses of neutrons having energies of 14 megaelectron volts. The blue line shows a pre-launch test of the instrument for comparison.
These data provide information about the content of water at the Curiosity landing site, and show that the instrument is in perfect shape for the first use of the neutron sounding technique in its interplanetary exploration. Later, when Curiosity is on the move, variations of the height and duration of this profile will indicate changes in the water content of the soil down to about 3.3 feet (one meter) below the surface.
The most likely hydrogen in the ground of Gale Crater is in hydrated minerals. These are minerals with water molecules or hydroxyl ions bound into the crystalline structure of the mineral. They can tenaciously retain water from a wetter past after all free water has gone.
Image Credit: NASA/JPL-Caltech/Russian Space Research Institute