Frosty Mountains on Mars
Explanation:
What causes the unusual white color on some Martian mountains?
The answer can be guessed by noticing that the
bright areas disappear as
springtime
takes hold in the south of Mars: dry ice.
Unlike water ice,
dry carbon dioxide ice sublimates directly to
gas from its frozen state.
The frosty mountains, named
Charitum Montes, have been covered with
carbon dioxide ice over the Martian winter.
The serene scene
pictured above is not a photograph,
but rather a computationally constructed
digital illusion resulting from the
fusion of two color images from the
Mars Orbital Camera and topographic data from the
Mars Orbiter Laser Altimeter.
Both instruments operate from the
Mars Global Surveyor robot spacecraft currently orbiting
Mars.
The red planet continues to
grow larger in
terrestrial skies as
Earth and Mars move closer to their
recent-record closest approach on August 27.
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.
