With a dazzling display dancing across the sky over Alaska, a NASA sounding rocket blasted from Poker Flat Research Range this week to penetrate the aurora in an investigation of its mysterious energy waves.
In the last launch of Poker Flat’s season, a NASA Black Brant XII rocket lifted off at 11:39 p.m. on Feb. 27 with a payload of sensitive instruments in an experiment named CHARM, led by Jim LaBelle, a professor of physics and astronomy at Dartmouth College.
A NASA rocket launches in 2003 for a previous
experiment by Jim LaBelle
Courtesy Chuck Johnson, UAF Geophysical Institute
Arctic Science Journeys
The project (Correlations of High-Frequencies and Auroral Roar Measurements) was looking at the relationship between “Langmuir waves” — fluctuations in the soup of ions and charged particles found near the boundary between air and space — and auroral electrons of various energies, according to NASA.
It’s pretty complex stuff: think “rocket science” here. The scientists wanted to answer questions about how the waves grow and evolve, and how the electrons behave, and they needed to send a rocket up about 60 miles to reach the action.
LaBelle likes to describe the aurora as nature’s TV. Just as a television set fires electrons at a screen to create a picture, the aurora fires electrons at the earth’s atmosphere. Think of the atmosphere as like a giant television set and the aurora as the picture, and you get the idea.
But while the aurora is a fascinating phenomenon in itself, LaBelle is actually more interested in the effect of an aurora’s fast-moving electrons on the plasma-rich atmosphere at altitudes from about 100 to 600 kilometers above the earth.
LABELLE: “Unseen to the eye, the electrons that are fired down at the atmosphere set up waves and turbulence in the atmosphere, somewhat analogous to a speedboat plowing through the water and setting up a wake of waves or turbulence around it. These waves are of interest to us.
“It turns out that at altitudes where the aurora occurs, the atmosphere is dominated by plasma. That is a gas of charged particles. The waves and turbulence in the plasma is much more complex. The aurora turns out to be an excellent natural laboratory to investigate these complicated plasma waves.”
After this most recent flight, LaBelle told the Geophysical Institute, “We got good data off one of our antennas. … There might be something new in there about high-frequency waves. There’s still a chance we’ll be able to get a scientific paper or two out of the data set.”
Clay Merscham and Shane Thompson releasing booms
on the LaBelle payload prior to Spin/Balancing.
NASA Sounding Rockets Program
The Poker Flats Research Range, 30 miles up the Steese Highway from Fairbanks, has been operated by the Geophysical Institute for nearly four decades. Now under contract to NASA, the facility has launched more than 2,000 rockets since 1969.
Including several other projects, Poker Flats has launched 10 NASA rockets in four different experiments during a season that begain January. All investigated different aspects of the aurora.