Scientists in Alaska bounced radio signals off a small asteroid Tuesday from the High-frequency Active Auroral Research Program research site in Gakona.
The experiment was preparation for a more spectacular near-Earth asteroid fly-by in six years.
Early Tuesday, the HAARP research site in Gakona transmitted radio signals to the little rock named asteroid 2010 XC15. It is not as close as some asteroids get, according to Mark Haynes, the lead investigator on the project and a radar systems engineer at NASA’s Jet Propulsion Laboratory.
“There are lots of small asteroids that fly between us and the moon. It happens about once a week,” Haynes said. “But this is the first time we’re trying to do this with very low frequencies or very long wavelengths, and the difference is these long wavelengths, you know, can penetrate the interiors of the asteroids.”
That’s where HAARP comes in. Despite its “High-frequency” in its name, this experiment used low frequencies. Haynes said it is the lowest-frequency, highest-power transmitter available for JPL and NASA to use. In the experiment, HAARP “chirps” about every 2 seconds, sending radio waves up to the asteroid to bounce back to Earth.
“They’re gonna steer their beam at the asteroid. We’ve got two radio observatories — one’s in California, the Owens Valley Long Wavelength Array, and one is in New Mexico, the New Mexico Long Wavelength Array. They’re both going to receive the signal, so HAARP transmits and these radio observatories, they’re gonna track it for about 12 hours,” Haynes said.
Tuesday’s experiment is the first time HAARP’s signals have probed an asteroid. The experiment tests the potential use of HAARP for sensing what is inside of near-Earth asteroids.
“The hope is if we get these systems working together, then eventually we can probe the interiors of these asteroids, as they come close,” Haynes said.
Haynes said there is another flyby coming relatively soon, in six years.
On April 13, 2029, asteroid Apophis, will pass less than 20,000 miles from our planet’s surface — closer than our geosynchronous satellites.
“ In 2029, Apophis will get very close,” Haynes said. “It’ll be about one-tenth the distance between us and the moon, and it’s gonna be a big event. And that’s an opportunity that we have to try to actually probe the interior of the thing while it’s flying past. These experiments with HAARP and the radio observatories are kind of a rehearsal.”
In 2021 the University of Alaska Fairbanks received a five-year, $9 million National Science Foundation grant to establish and operate the “Subauroral Geophysical Observatory for Space Physics and Radio Science” at HAARP.
Haynes said it will take months to process the data from Tuesday’s asteroid bounce.