Aug
22,
2006
Missing Air of Mars
Mars has an atmosphere only one hundredth as dense as the
Earth's. Before space probes visited it, astronomers
expected it to be ten or more times thicker than it is.
ESA's Mars Express orbiter has come up with a
possible explanation for the "missing atmosphere" of Mars
(see illustration above). The orbiter has been measuring how
much atmosphere is being removed from Mars today by solar
wind interactions. The total is about 1 kilogram (2.2
pounds) per second, or about 100 tons per day. That's not
fast enough to have depleted Mars' atmosphere in the
accepted length of Martian history, but presumably when
there was more atmosphere, the process happened faster.
But the concept breaks down when you consider Venus. By
standard theory, Venus, Earth and Mars have a common origin
in the solar nebula. They must have received similar
original amounts of air and water. Earth has held on to most
of its air and water because it has a magnetic field to
protect it from the solar wind. Neither Venus nor Mars have
magnetic fields today (although Mars is thought to have had
one early in its history). If Venus has been bombarded by
solar wind for as long as Earth and Mars, then its
atmosphere should have been depleted, too. But it isn't.
Instead, Venus' atmosphere is 90 denser than Earth's
atmosphere.
For the Electric
Universe, there is no reason to think of Venus, Earth and
Mars as siblings. Nor is it reasonable to think of them as
moving along the same orbits for billions of years. Each
planet had a separate birth, and even if some or all were
born in the same set of plasma instabilities, their
characteristics would be dependent on the composition and
discharge history of the particular plasma cell in which
they were individually formed.
After the birth
event, the planets also have a history. Each of them took
part in several catastrophic events, the most recent of
which is commemorated by prehistoric humans in rock art and
in myth. It isn't necessary to suppose that Mars has been
losing 100 tons of air a day for billions of years because a
few thousands of years ago Mars went through a major event
that could have stripped it of its atmosphere and oceans all
at once. Plasma interactions were undoubtedly involved;
history remembers them as the magical thunder weapon of the
warrior hero. But these plasma interactions were much more
active than those described above by the Mars Express
researchers.
Electric
discharge will sometimes take away material (as in the 100
tons per day from the Martian atmosphere). But it can also
deposit new material in sorted layers. Or even a whole new
atmosphere. As space probes have returned data about density
of atmospheres among our solar neighbors, astronomers have
been surprised in many cases. Too much air on Venus and
Titan; too little on Mars. Earth is considered the "just
right" example of how much air a planet should retain for
its mass. But electrically speaking, there is no standard
initial atmosphere and subsequent changes are not
necessarily slow or steady. No wonder the planetary
atmospheres don't appear to comply with the astronomical
texts.
___________________________________________________________________________
Please visit our
Forum
The Electric Sky
and The Electric Universe
available now!