This infrared image from NASA’s Spitzer Space Telescope shows the broken comet 73P / Schwassman-Wachmann 3 traversing a trail of debris left during its multiple orbits around the sun. Flame-like objects are fragments of the comet and its tails, while the trace of the dusty comet is the line joining the fragments. Credit: NASA
Astronomers are excited about the possibility of a new meteor shower from May 30 to 31, the Herculid Tau rain, which is expected to peak on the night of May 30 and the morning of May 31.
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 weak, SW3 was not seen again until the late 1970s, which seemed quite normal until 1995, when astronomers realized that the comet had become about 600 times brighter and ‘a faint spot to be visible to the naked eye during its passage. After further investigation, astronomers realized that SW3 had broken into several pieces, littering its own orbital trail with debris. When it came our way again in 2006, it was in almost 70 pieces and has continued to fragment even further ever since.
If it comes to us this year, SW3 debris will hit the Earth’s atmosphere very slowly, traveling at only 10 miles per second, which means much weaker meteors than those belonging to the eta Aquariids. But U.S. star watchers are taking special note this year because the radiant tau Herculid will be high in the night sky at the scheduled rush hour. Even better, the Moon is new, so there will be no moonlight to clear the faint meteors.
“This will be an all-or-nothing event. If SW3 debris was traveling at more than 220 miles per hour when it separated from the comet, we could see a good meteor shower. If the debris had slower ejection rates, nothing would come of it. on Earth and there will be no meteors from this comet, “said Bill Cooke, who heads NASA’s Office of the Meteorological Environment at NASA’s Marshall Space Flight Center in Huntsville, Alabama.
All the excitement of the astronomers and the public has aroused much information about the Tau Hercules. Some have been accurate, and some have not.
We are also thrilled by the meteor showers! But sometimes events like this don’t live up to expectations; for example, it happened with the Alpha Monocerotid rain of 2019. And some astronomers predict that a dazzling display of Hercules tau could be “right or wrong.”
We therefore encourage eager sky observers to channel their inner scientists and look beyond the headlines. Here are the facts:
- On the night of May 30 to the morning of May 31, the Earth will pass through the remains of a broken comet called 73P / Schwassmann-Wachmann, or SW3.
- The comet, which shattered into large fragments in 1995, will not reach this point in its orbit until August.
- If the fragments were ejected at speeds in excess of twice the normal speed, fast enough to reach Earth, we could have a meteor shower.
- Spitzer’s observations published in 2009 indicate that at least some fragments are moving fast enough. This is one of the reasons why astronomers are so excited.
- If a meteor shower occurs, the Herculean tau move slowly by meteorite standards: they will look weak.
North American observers under clear, dark skies have the best chance of seeing a Herculean tau rain. Rush hour to watch is around 1am on the east coast or 10pm on the west coast.
We can’t be sure what we’ll see. We can only hope it’s spectacular.