The Spiral North Pole of Mars
Explanation:
Why is there a spiral around the North Pole of Mars?
Each winter
this pole
develops a new outer layer about one meter thick composed of
carbon dioxide frozen out of the thin Martian atmosphere.
This fresh layer is deposited on a water-ice layer that exists year round.
Strong
winds blow down
from above the cap's center and swirl due to the spin of
the red planet --
contributing to
Planum Boreum's spiral
structure.
The
featured image is a perspective mosaic generated earlier this year from numerous
images taken by ESA's
Mars Express and elevations extracted from the
laser altimeter aboard NASA's
Mars Global Surveyor
mission.
New missions to Mars planned in the next few years include
Insight
with plans to drill into Mars, and
ExoMars
and the
Mars 2020 Rover
with plans to
search for signs of microscopic Martian life -- past and present.
Free APOD Lectures:
January 5 in NYC & January 9 in DC
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.
