BIG SUNSPOT PRODUCES "OCEAN SURF" SOUNDS: If you have a shortwave radio, you might have heard some unusual sounds this week. Big sunspot AR2738 is producing strong bursts of radio static. "They sound like ocean surf," says Thomas Ashcraft, who recorded this specimen on April 13th using an amateur radio telescope in New Mexico:






These radio sounds are caused by beams of electrons--in this case, accelerated by B-class explosions in the sunspot's magnetic canopy. As the electrons slice through the sun's atmosphere, they generate a ripple of plasma waves and radio emissions detectable on Earth 93 million miles away. Astronomers classify solar radio bursts into five types; Ashcraft's recording captured a Type III.
"There have been a lot of these sounds over the past week, and they appear to be intensifying now that the sunspot is  directly facing Earth," says Ashcraft.

Readers, if you would like to detect solar radio bursts in your own backyard, order a radio telescope kit from NASA's RadioJOVE project.