Magnetic Mars
Credit & Copyright: Jack Connerney, Mario Acuna, Carol Ladd,
MGS,
NASA
Explanation:
Mapping Mars from orbit,
instruments on the Mars Global Surveyor (MGS)
spacecraft have recently revealed
banded magnetic field patterns - a
startling and unanticipated suggestion that the Red Planet was more
Earth-like in its distant past.
The red and blue regions within the MGS orbital tracks
across this portion of southern Mars indicate adjacent areas of
crust where magnetic fields
point in opposite directions.
The bands seem to run east-west and are about 100 miles wide and
600 miles long.
Such patterns are known to be produced on Earth by
plate tectonics.
As the crustal plates spread apart along
the mid-ocean ridges, they
carry a progressive banded record of Earth's changing magnetic field.
The similar patterns on Mars are seen as evidence that it too once
had moving crustal plates and a changing magnetic field,
although both processes - still active on the
larger planet Earth -
are thought to have long since died away.
These high resolution measurements of martian magnetism were
made possible by the revised, close
aerobraking orbits of the
MGS spacecraft and not originally planned.
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.
