A once-lost, crumbling comet could bring a brand new meteor shower to Earth next week.
The shower, dubbed Dew Herculids, is scheduled to fall from the shattered SW3 comet beginning May 30 and peak between 12:45 p.m. and 1:17 a.m. EDT on May 31 and hit the skies over the United States and parts of Canada light up with some short but bright streaks of flame.
NASA astronomer Bill Cooke described the comet’s possible imminent appearance in a NASA statement as an “all-or-nothing event.” The show would be the result of debris thrown off a fragment of the comet. While comet debris most often falls behind the comet fragment to form the tail, it can sometimes be ejected at such a high velocity that the chunks of ice and rock are ejected in front of the comet. In order for us to see this debris as it burns in our atmosphere, the American Meteor Society (AMS) says it must be either large enough or fast enough to burn brightly as our planet traverses its path.
Related: Why do asteroids and comets have such strange shapes?
“If the wreckage of SW3 was traveling at more than 220mph [354 km/h] When it separates from the comet, we might see a nice meteor shower,” Cooke said. “If the debris had slower ejection speeds then nothing will reach Earth and there will be no meteors from this comet.”
Comet SW3 or 73P/Schwassmann-Wachmann was named after its discoverers, German astronomers Arnold Schwassmann and Arno Arthur Wachmann. The pair first discovered and cataloged SW3 in 1930 and confirmed from orbital observations that it was in a 5.4-year orbit. At its closest visit on May 31, 1931, the comet was only 5.7 million miles (9.2 million kilometers) from Earth, but it was quite dim and could only be seen through telescopes.
Then, in 1935, the comet disappeared from view, coming and going eight times without being seen until finally being rediscovered in 1979. The comet remained faint until its 1995 flyby, when it returned nearly 400 times brighter and visible to the naked eye. Further study soon revealed that SW3’s brightness was due to an amazing transformation – its icy core had shattered into four fragments, and by 2006 the shattered comet had split into 68 pieces. In the 16 years since, it has likely collapsed even further.
The best places to see the meteor shower will be in the southwest, the AMS said.
“The US Southwest and Mexico are preferred locations because the radiant, the region of the sky where these meteors come from, will be highest in a dark sky,” wrote Robert Lunsford on the society’s blog. “Alaska and Washington are being bathed in twilight at this time, ruining their chance of seeing anything. The same applies to the northern and western Canadian provinces. The eruption can be seen from southeastern Canada and the rest of the (eastern) US, but at a lower altitude.”
The best place to look for the comet is in the Boötes constellation, which is right next to the star Arcturus, according to EarthSky. In addition, since the moon is in a new phase, the sky will be dark, making it easier to observe. To spot this shower, a viewing room that’s as dark as possible is recommended, as many of its smaller chunks move slowly – meaning they burn dimly and may not be visible. However, since the display could also contain larger fragments, there’s a chance the shower will contain some stunning slow-moving fireballs.
“When it comes to us this year, the debris from SW3 will hit Earth’s atmosphere very slowly, traveling only 10 miles [16 km] per second — meaning much fainter meteors than those of the Eta Aquariids,” NASA wrote in its blog post.
Originally published on Live Science.
https://www.livescience.com/shattered-comet-tau-herculids-meteor-shower Shattered comet could produce dazzling meteor shower: How to watch the tau Herculids