Earth is expected to pass through the trail of debris from a fragmented comet on Monday night and Tuesday morning. This could produce a new meteor shower.
Night sky watchers in North America have the best chance of seeing the Herculid tau shower, with NASA recommending around 1 a.m. on the East Coast or 10 p.m. on the West Coast as the best times to look up. The moon is new, so there will be no moonlight to obscure the meteors.
However, there is no guarantee of a dazzling show even if the sky is clear and dark, NASA stressed. It could really be nothing.
The comet, officially known as 73P/Schwassmann-Wachmann, or SW3, was discovered in 1930 by German observers Arnold Schwassmann and Arno Arthur Wachman. It wasn’t seen again until the late 1970s, and in the 1990s, the comet broke up into several pieces, according to NASA.
When SW3 passed by Earth again in 2006, it was in nearly 70 pieces, and has continued to fragment ever since, according to the statement.
An infrared image from NASA’s Spitzer Space Telescope shows the broken comet 73P/Schwassman-Wachmann. The flame-shaped objects are the comet fragments and their tails, while the dusty comet trail is the line between the fragments.
NASA said Spitzer Space Telescope observations released in 2009 indicated that some fragments are moving fast enough to be visible, which excites space scientists.
Every year there are about 30 meteor showers, which happen when the Earth passes through the trail of debris left by a comet or asteroid, which are visible to the naked eye.
Some meteor showers have been around for centuries. For example, the Perseid meteor shower, which occurs every year in August, was first observed about 2,000 years ago and recorded by Chinese astronomers, according to NASA. New meteor showers like this, should they materialize, are relatively rare.
It is all or nothing
Debris from SW3 will hit Earth’s atmosphere more slowly than other meteor showers, and it is the speed at which the debris hits, rather than the size of the debris, that causes the shower.
Even if they are visible, this means the meteors will be much fainter than, for example, the eta Aquarid meteors seen this month.
“This is going to be an all-or-nothing event. If the debris from SW3 was traveling faster than 354 km/h when it separated from the comet, we could see a good meteor shower. If the debris had a slower ejection velocity, then nothing will reach Earth and there will be no meteors from this comet,” Bill Cooke, who directs NASA’s Meteorological Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, said in a statement.
Meteor showers are usually named after the constellation from which they appear to radiate in the night sky, although Robert Lunsford, secretary general of the International Meteor Organization, said the tau herculids had been given a misname.
The scientist believes that they appear to radiate from a constellation known as Bootes, northwest of the bright orange star known as Arcturus (alpha Bootis).
“The radiant is expected to be a large area of the sky and not a landmark. Therefore, any slow meteors in this general area of the sky can be expected to come from SW3,” Lunsford said in a blog post.
“You don’t need to look straight up, as meteors can appear anywhere in the sky. In reality, they are more likely to appear in the lower parts of the sky, since at this height you are looking through a portion of much thicker atmosphere than when looking straight up.
More meteor showers
If the Tau Herculeid shower turns out to be a dud, fear not, there are other opportunities to witness other meteor showers this year.
Delta Aquarids will be best seen from the southern tropics on July 28-29, when the moon is nearly full.
Interestingly, another meteor shower peaks that same night: the Alpha Capricorns. While this is a much weaker shower, it is known for producing some bright fireballs during its peak.
This rain will be visible to everyone, regardless of which side of the equator they are on.
The Perseid meteor shower, the most popular of the year, will peak between August 11 and 12 in the northern hemisphere, when the moon is 13% full.
This is the list of meteor showers remaining in 2022, according to EarthSky:
- Southern Delta Aquarids: July 29-30
- Alpha Capricornids: July 30-31
- Perseids: August 11-12
- Orionids: October 20-21
- Southern Taurids: November 4-5
- Northern Taurids: November 11-12
- Leonidas: November 17-18
- Geminids: December 13-14
- Ursids: December 21-22