APOD: 2025 July 6 Б 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 in 2017 from numerous images taken by ESA's Mars Express and elevations extracted from the
laser altimeter aboard NASA's
Mars Global Surveyor mission.
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.
