Jagged Hills on Jupiters Callisto
Explanation:
Why does Jupiter's moon Callisto
have unusual jagged hills?
This mystery came to light after the
robot spacecraft
Galileo, in orbit around
Jupiter since 1995, swooped past the
dark moon in May.
The
resulting pictures were the highest resolution yet obtained for a
Jovian moon: objects as small as 3 meters across are discernable.
The strange landscapes
pictured above show areas rich in bright sharp mounds about 100 meters tall.
A likely
formation hypothesis holds that these hills are the
result of ejecta thrown billions of years ago during a
violent impact.
The lower inset region apparently has
undergone an epoch of relatively high
ice-
erosion, where dark rock has filled in
some of the inter-hill regions.
NASA has
recently cleared Galileo to continue swooping
Jupiter's moons until 2003, when it will
end its journey with a
spectacular dive into
Jupiter's atmosphere.
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.
