| News | December 2001 |
Movies
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Animation depicting various aspects of the
Sun-Earth system...the Sun, the corona and solar wind, space plasmas
flowing around the magnetosphere of Earth and funneling into the system
in places. Cluster is designed to make multi-point measurements of
those flowing plasmas. Courtesy of the European Space Agency
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Animation of the Cluster spacecraft as they glide
over Earth's northern lights for a view.
Courtesy of the European Space Agency |
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Animation depicting the Cluster quarter of
spacecraft flying in formation and viewing Earth's magnetosphere from
different angles as it undulates in response to a space storm.
Courtesy of the European Space Agency |
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Still Images
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Artist's conception of the black aurora and its
associated electric currents, as observed by the four Cluster
spacecraft.
Courtesy of the European Space Agency
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View of the aurora over the Northern Hemisphere from the Polar
spacecraft
Courtesy of VIS/University of Iowa
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View of the aurora over both poles of Earth (known as "conjugate
aurora") from the Polar spacecraft
Courtesy of VIS/University of Iowa
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Location and configuration of the Cluster satellite formation
passing over the northern hemisphere auroral oval between 4:20 and 4:40
UT on January 14, 2001, in the recovery phase of a weak substorm,
peaking at 04:00 UT. a) The nightside auroral oval as observed by the UV
imager on the IMAGE satellite at 04:30 UT. The ionospheric projection of
the Cluster orbit (between 4:20 and 04:45 UT) is shown by the white line
intersecting the auroral oval. b) Relative positions and time
differences between the Cluster 1, 2, and 4 spacecraft with respect to
the reference Cluster 3 (Samba) in a plane transverse to the magnetic
field. The four Cluster spacecraft are aligned nearly as pearls on a
string, with the separation transverse to the velocity vector being
small, and follow in the sequence 1-3-2-4.
Courtesy of the European Space Agency
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Upward accelerated electron beam: evolution of energy and
width. Time energy spectrograms show electrons moving anti-parallel to
the magnetic field as measured by the PEACE instrument between 4:30 and
4:40 UT. The arrowheads at the top of the panels indicate the encounters
with the bipolar electric field structures, occurring at a transition
between two characteristically different electron populations, a
high-energy isotropic electron population characteristic of the central
plasma sheet to the south, and a lower-energy population characterized
by intermittent, bi-directional, and field-aligned electron bursts.
Courtesy of the European Space Agency
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Acceleration structures within the auroral current circuit.
This schematic picture shows a negatively charged potential structure
representative of the aurora (left) and a positively charged potential
structure representative of the auroral return current (right). The two
branches of the equipotential contours close at typical altitudes of
5000-8000 km in the upward current region above the aurora and at
1500-3000 km in the auroral return current region, respectively, above
which they extend to very high altitudes along the geomagnetic field,
forming the characteristic U-shape. Together with the ionospheric
closure current and the magnetospheric generator these form the complete
auroral current circuit.
Courtesy of the European Space Agency | ||
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Artist's schematic of the position/observations of
the four Cluster spacecraft as they passed through the electric currents
of the black aurora.
Courtesy of the European Space Agency
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Author:Mike Carlowicz
Official NASA Contact: ISTP-Project
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