does a scientist stuck on Earth know what
the weather's like in space, or which way
the solar wind is blowing? Fitted with
sensors and telescopes, satellites like
SOHO (Solar & Heliospheric Observatory)
turn space into a vast lab, where scientists
study how magnetic fields and plasmas behave.
spacecraft are Earth’s early warning
system, letting us know when potentially
dangerous events are taking place in space,
or might soon occur.
THEMIS: NASA's Time History of Events and
Macroscale Interactions during Substorms
(THEMIS) aims to resolve one of the oldest
mysteries in space physics, to determine
what physical process in near-Earth space
initiates the violent eruptions of the
aurora that occur during substorms in the
THEMIS is a 2-year mission consisting of 5
identical probes that were launched in 2007.
The mission will study the violent eruptions
in Earth’s magnetotail region that result in
the beautiful auroras near the poles.