(music)
Hi, I'm David
Sibeck NASA's project scientist for the THEMIS mission. We're looking at
results from a global simulation of the solar winds interaction
with the earth's magnetic field. The sun is located far to the
left, far outside the picture we're looking at. The Earth is the
small blue dot, at the center of the cavity carved out by the
Earth's magnetic field in the oncoming super sonic solar
wind. The boundary to the left in the figure, is the magnetopause,
the outer most reaches of the earth's magnetic field.
The earth's magnetic field is buffeted by the solar wind, flapping back and forth,
like a windsock in a gust of wind. Only a
small fraction of the solar wind mass, momentum, and energy succeed
in entering the earth's magnetic field. The process that controls that
entry is magnetic reconnection. Reconnection takes energy
away from the magnetic field and gives it to the particles in the
plasma. The typical result of reconnection is high-speed flows,
of energized particles streaming away from the reconnection site.
The wispy white structures that you see, are regions where
energy is being released from the magnetic field and converted into
accelerated plasma flows. We're now looking at flows within the
simulation. The arrows indicate the direction the plasma is moving with
red, indicating flows at very high speeds. Within the magnetotail,
on the right side of the picture we see that the arrows are associated
with the wispy white regions where energy is being converted from
the magnetic field, to the plasma, by reconnection. Now we're looking at a
time later in the simulation. The sight of reconnection
has moved far down the earth's magnetotail and is generating flows of
plasma, that is arrows, that move to the left towards the
earth, and towards the sun.
(beeping)