The Delta II rocket raced into space on the flaming power of three rocket stages and nine solid rocket motors, after which the THEMIS satellites soon after dispersed around Earth to monitor auroras like the Northern Lights.

NASA reports that they are “undertaking the mission to investigate what causes auroras in the Earth's atmosphere to change in appearance and dissipate. Discovering why the light of auroras can fluctuate and fade will provide scientists with important details on how the planet's protective magnetosphere works and on the sun-Earth connection”.

According to NASA, THEMIS is a mission to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection.

An excerpt from the THEMIS mission information linked in the previous paragraph explains why the mission is important:

During substorms, the solar wind overloads the magnetosphere with too much energy and the stretched magnetic field lines snap back like an enormous slingshot, energizing and flinging electrically charged particles towards Earth. Electrons, the particles that carry electric currents in everything from TVs to cell phones, stream down invisible lines of magnetic force into the upper atmosphere over the polar regions. This stream of electrons hits atoms and molecules in the upper atmosphere, energizing them and causing them to glow with the light we know as the aurora.

The same electrons sometimes charge spacecraft surfaces, resulting in unexpected and unwanted electrical discharges. And those electrons that enter the radiation belts can ultimately find their energies boosted to levels millions of times more energetic than the photons that comprise the light we can see. Electrons with these energies can damage sensitive electronics on spacecraft and rip through molecules in living cells, potentially causing cancer in unshielded astronauts. Rapidly varying magnetic fields associated with magnetospheric substorms also induce electric currents in power lines that can cause blackouts by overloading equipment or causing short circuits.

Although the consequences of substorms are well-known, it is not clear exactly what finally snaps in the overloaded magnetosphere to trigger a substorm.

Understanding what happens during substorms is important. "The worst space storms, the ones that knock-out spacecraft and endanger astronauts, could be just a series of substorms, one after the other," said David Sibeck of NASA's Goddard Space Flight Center in Greenbelt, Md., project scientist for the THEMIS mission. "Substorms could be the building block of severe space storms."

Just like meteorologists who study tornadoes to understand the most severe thunderstorms, space physicists study substorms for insight into the most severe space storms. “Substorm processes are fundamental to our understanding of space weather and how it affects satellites and humans in the magnetosphere,” said Vassilis Angelopoulos, THEMIS principal investigator at the University of California's Berkeley Space Sciences Laboratory, in Berkeley, Calif. Scientists propose two possible triggers for substorms, but until now, there has been no way to distinguish between the two models.

You can read the rest of the THEMIS mission information at NASA’s site linked above. Let’s hope NASA is more than successful as this information will be crucial to future travel into space, the existing space station, an initial moon base and an eventual lunar colony, before humanity eventually spreads further out into the galaxy.
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Alex Zaharov-Reutt  Earth  NASA  Research  Science  Solar system  Space  Space Station  Universe