Tau Herculids

If predictions hold true, we may be in for a rare meteor outburst with up to 1000 meteors per hour... or we may see nothing at all. 

A possible newcomer this year is the tau Herculid shower, forecast to peak on the night of May 30 and early morning of May 31. That's next Monday into Tuesday.

Back in 1930, German observers Arnold Schwassmann and Arno Arthur Wachmann discovered a comet known as 73P/Schwassmann-Wachmann, or “SW3, which orbited the Sun every 5.4 years. Being so faint, SW3 wasn’t seen again until the late 1970s, seeming pretty normal until 1995, when astronomers realized the comet had become about 600 times brighter and went from a faint smudge to being visible with the naked eye during its passage. Upon further investigation, astronomers realized SW3 had shattered into several pieces, littering its own orbital trail with debris. By the time it passed our way again in 2006, it was in nearly 70 pieces, and has continued to fragment further since then.

If it makes it to us this year, the debris from SW3 will strike Earth’s atmosphere very slowly, traveling at just 10 miles per second – which means much fainter meteors than those belonging to the eta Aquariids. But North American stargazers are taking particular note this year because the tau Herculid radiant will be high in the night sky at the forecast peak time. Even better, the Moon is new, so there will be no moonlight to wash out the faint meteors.

“This is going to be an all or nothing event. If the debris from SW3 was traveling more than 220 miles per hour when it separated from the comet, we might see a nice meteor shower. If the debris had slower ejection speeds, then nothing will make it to Earth and there will be no meteors from this comet,” Cooke said.