On Feb. 13th, the loudspeaker of Thomas Ashcraft's 21 MHz radio telescope in New Mexico suddenly began to hiss and crackle. The sounds grew louder as Jupiter rose in the pre-dawn sky. "I am pleased to report," says Ashcraft, "a successful recording of Jovian S-bursts--the first of 2008." Click here to listen:
The stacatto pops sound like lightning in the loudspeaker of a car radio, but lightning did not make these sounds. S-bursts are caused by natural radio lasers that form in Jupiter's magnetosphere and 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.
Jupiter is just finishing a weeks-long passage around the backside of the sun; now it is emerging into the pre-dawn sky in good position for radio observing. "Feb. 13th was one of the first opportunities to observe Io-storming this year," says Ashcraft. "It is encouraging for future monitoring of Jupiter in the months ahead."
Jupiter is just finishing a weeks-long passage around the backside of the sun; now it is emerging into the pre-dawn sky in good position for radio observing. "Feb. 13th was one of the first opportunities to observe Io-storming this year," says Ashcraft. "It is encouraging for future monitoring of Jupiter in the months ahead."
