How long does it take to radio the Moon? 2.4 seconds.
Radar pulses from the HAARP research station outside Gakona in Alaska’s Copper River basin have been bounced off the moon and picked up by a radio telescope system in New Mexico — the lowest frequency radar echo from the moon ever detected on the home planet.
The signals, beamed skyward from antennas at the sometimes controversial High Frequency Active Auroral Research Program, zapped the moon in a manner somewhat like sonar, and then illuminated secrets of the ionosphere as they returned to Earth.
These pulses were then caught by newly developed receivers at the Longwave Length Array in the New Mexico desert, an ongoing project to create a ground-breaking (and inexpensive) radio telescope that will listen to space for as-yet unknown low frequency signals. (Motto: “Catching Big Waves with small blades.”)
“Detecting the very weak radio signals after their round trip to the moon and back was challenging and required careful modification of the LWA antennas to improve their performance at these frequencies,” says NRL Remote Sensing Division scientist, Dr. Kenneth Stewart.