Auroras have captivated observers for thousands of years. However, even with today’s advanced sensors, they still hold many mysteries. To gain a deeper understanding of their flickers and pulses, NASA plans to launch a mission targeting the regions in the U.S. where Northern Lights occur most frequently.
Alaska. NASA’s Goddard Space Flight Center is prepared to launch a sounding rocket from Alaska, despite the fact that most U.S. space activity typically occurs in warmer Florida.
The launch has been delayed several times due to adverse weather conditions. It’s now scheduled for the next few days from the Poker Flat Research Range in Fairbanks.
A flight through the aurora borealis. The mission is called Ground Imaging to Rocket Research of Auroral Fast Features (GIRAFF). The main goal is to send two sounding rockets to study two subtypes of aurora borealis:
- Fast-pulsing auroras flicker in a rhythmic pattern, with pulsations occurring every second. These are linked to a type of electromagnetic wave in the magnetosphere known as Alfvén waves.
- Flickering auroras display slower and more irregular variability. These auroras are characterized by flickers in the sky that appear to shift according to the flow of charged particles in the magnetosphere.
Aboard a modified missile. NASA is set to use Black Brant XI sounding rockets for the GIRAFF mission. These rockets have a first stage derived from the U.S. naval Talos missile and feature three solid fuel stages. They can carry a payload of up to 1,300 pounds to an altitude of 155 miles.
The GIRAFF mission aims to investigate the processes that create the optical variations in auroras. These mesmerizing displays are observable from Earth and can fluctuate at frequencies of up to 15 Hz or more.
The GIRAFF mission. NASA researchers are particularly interested in understanding why some auroras flicker, some pulsate, and some are riddled with “holes.” Their research will focus on two specific energy-coupling mechanisms: wave-particle interactions of low-altitude electromagnetic ion cyclotrons and chorus wave modulation in the equatorial magnetosphere.
To better understand these interactions, NASA will launch two identical rockets into a flickering and rapidly pulsating aurora. A second mission will launch two more rockets into the dark spots, or “holes,” of the auroras to further study this phenomenon.
Image | Vincent Guth
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