RADIO BURSTS FROM JUPITER
This week, Jupiter is passing behind the sun. Normally that would make it difficult for radio astronomers to pick up Jupiter's shortwave radio bursts. Because the sun is so quiet, however, Jupiter is still able to maake itself heard. "I was able to capture distinct narrow-band radio emissions from Jupiter on July 21st," reports Thomas Ashcraft of New Mexico. They are the sloping lines in this dynamic spectrum he recorded using a RadioJove Project dual dipole antenna.
"At the time Jupiter was 6.3 Astronomical Units (585,621,586 miles) distant from Earth," he adds. "I think this is a neat observation because it means there is always the possibility of receiving Jupiter radio emissions here on Earth--even when the sun is in the way and Jupiter is very distant."
Jupiter's radio storms are caused by natural radio lasers in the planet's magnetosphere that sweep past Earth as Jupiter rotates. Electrical currents flowing between Jupiter's upper atmosphere and the volcanic moon Io can boost these emissions to power levels easily detected by ham radio antennas on Earth. Jovian "S-bursts" and "L-bursts" mimic the sounds of woodpeckers, whales, and waves crashing on the beach. Here are a few audio samples: S-bursts, S-bursts (slowed down 128:1), L-Bursts. The type of emissions Ashcraft picked up on July 21st were S-bursts.
23 Jul 2014