Neutron Mars
Explanation:
Looking
for water on Mars, researchers using detectors
on board the orbiting
Mars Odyssey spacecraft have
created this
false-color global map
of energetic neutrons from the otherwise
Red Planet.
What do
neutrons have to do
with water?
As
cosmic rays
from interplanetary space penetrate the thin martian
atmosphere and reach the surface they
interact with elements in
the upper layer of soil, scattering neutrons back into space.
But if the martian soil contains hydrogen, it seriously absorbs
energetic scattered neutrons.
Tracking variations in absorption,
neutron detectors
can map changes in surface hydrogen content from orbit.
Hydrogen content is taken as a surrogate measure of
frozen water (
H20),
the most likely
form of hydrogen
close to the martian surface.
Blue shades in the above map correspond to large concentrations
of hydrogen, indicating in particular that the martian
south polar
region has a high amount of water ice near the surface.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
