Rocketing
Into the Northern Lights
February
9, 2013
Auroras are a visible reminder of our planet’s connection to
space. The “northern lights” and “southern lights,” as they are more commonly
known, are like a rain of highly energized particles from the space around
Earth. Provoked by storms and winds from the Sun, electrons trapped inside
Earth’s magnetic field (magnetosphere) accelerate down toward the upper
atmosphere (ionosphere), where they smash into oxygen and nitrogen molecules
and release photons of green, red, and blue light. The light shows can take the
shape of waving curtains or rays or diffuse clouds.
At the same time that particles are raining down from space,
others are leaving. The “auroral wind” is a strong but intermittent stream of
oxygen atoms that flow from the atmosphere into outer space during northern
lights shows. Scientists from NASA’s Goddard Space Flight Center and The
Aerospace Corporation, together with the support team from the University of
Alaska’s Geophysical Institute, launched a rocket from the Poker Flat Research
Range to study this little-understood emission from the atmosphere. The
NASA-sponsored VISIONS campaign—VISualizing Ion Outflow via Neutral atom
imaging during a Substorm—was designed to fly instruments into the aurora for a
fifteen-minute close-up examination.
The photo above was taken by Sebastian Saarloos, an amateur photographer who was
watching the launch from Delta Junction, Alaska, about 120 miles (195
kilometers) southeast from Poker Flat. He captured the image of the rocket
streaking into the aurora at 11:21 p.m. local time on February 6, 2013.
Most of the atmosphere is bound by Earth’s gravity, but a small
portion gets heated enough by the aurora that it can break free and flow
outwards into near-Earth space. The atoms that form this wind initially travel
at just 300 miles per hour—only one percent of the speed needed to overcome
gravity and leave Earth's atmosphere.
“This
oxygen would normally never gain enough energy to leave the atmosphere,” said
Doug Rowland, principal investigator for VISIONS and a member of NASA’s Space
Weather Laboratory. “On the other hand, at very high altitudes, satellite
experiments have measured oxygen atoms moving faster than 50 miles per second.
These experiments have shown that if oxygen can reach these high altitudes,
there are plenty of ways for it to gain even more energy and escape near-Earth
space entirely. What we don’t know is how the oxygen gets enough energy to
fight against gravity and reach the higher altitudes where these slingshots are
active.”
You can observe a short video of the launch by clicking here.
· Related Reading
· Carlowicz, M.J. and Hill, S. (2002) NASA
Poster: Aurora—Fabled Glowing Lights of the Sun-Earth Connection. (PDF) Accessed February 8, 2013.
· Geophysical Institute, University of Alaska–Fairbanks (2013,
February 7) Successful
Launch From Poker Flat Research Range. Accessed February 8, 2013.
· NASA (2013, January 31) VISIONS:
Seeing the Aurora in a New Light. Accessed
February 8, 2013.
· NASA (2013, February 7) VISIONS:
A Successful Launch. Accessed
February 8, 2013.
Photograph copyright Sebastian
Saarloos. Caption by
Mike Carlowicz, Earth Observatory, and Claire De Saravia, NASA-GSFC, with
reporting from Amy Hartley, University of Alaska Geophysical Institute.
Instrument:
Photograph
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