Space & Earth Science
NORAD ID: 30797
Int'l Code: 2007-004D
Perigee: 1,024.4 km
Apogee: 68,014.8 km
Inclination: 8.3 °
Period: 1,371.5 minutes
Semi major axis: 40890 km
Launch date: February 17, 2007
Source: United States (US)
Comments: Aiming to uncover the physics that power the auroras that crown Earth's poles, five tiny probes have been launched into space for a synchronized orbital dance to locate where the trigger is pulled to create the eerily magnificent displays. Each of the 282-pound spacecraft is equipped with identical suites of instruments to examine the origin of space explosions known as substorms. The events start with the soup of ionized particles from the sun, called the solar wind, buffeting the Earth at a million miles per hour. Some of that energy gets trapped in the magnetic field, causing the field lines to stretch back in the direction opposite the sun like rubberbands. But when stretched too far the lines snap, releasing the energy that generates shimmering auroral displays.
Two Line Element Set (TLE):
1 30797U 07004D 13170.34483654 .00000000 00000-0 10000-3 0 7123
2 30797 008.2822 033.6125 8191412 100.3931 349.0975 01.04994781 22546
Source: AFSPC
NASA's NSSDC Master Catalog entry for THEMIS D