Meteors: The Arietids
Every year in early June thousands of meteors streak across the sky. Most are invisible, though, because the Sun is above the horizon while the shower is most intense. These daylight meteors are called the Arietids. They stream from a radiant point in the constellation Aries, which lies just 30 degrees from the Sun in June. No one is sure where Arietid meteoroids come from, although some astronomers suspect they are debris from the sungrazing asteroid 1566 Icarus. Another possibility is that the Arietids come from the breakup of a giant comet thousands of years ago.
Above: "Hey Joe, what was that?" A fanciful view of a daylight Arietid fireball, by artist Duane Hilton. Bright sunlight renders most Arietids invisible.
If you want to see a few Arietids, try looking just before sunrise. The Arietid radiant rises in the east about 45 minutes before the sun. (This is true for observers in both of Earth's hemispheres, north and south.) Pre-dawn Arietids tend to be "Earthgrazers"--meteors that skim horizontally through the upper atmosphere from radiants near the horizon. Spectacular Earthgrazers are usually slow and bright, streaking far across the sky--worth waking up for!
Above: This image shows the area of sky around the Arietid radiant (indicated by a red dot) as seen from mid-northern latitudes at 4 a.m. on June 8th. A southern hemisphere map is available, too.