A never-before-seen meteor shower could light up the sky with countless bright evening streaks from Monday night through Tuesday morning.
Or the event could run out of steam and be a dud.
These are the best predictions meteor spotters have for the Tau Herculids, a potential celestial spectacle that awaits skywatching enthusiasts.
Meteor showers can occur when Earth sinks into debris produced by a comet (or, occasionally, asteroids). The source of the Tau Herculids is Comet 73P/Schwassmann-Wachmann 3, or SW3 for short. Discovered in 1930, the insignificant ball of ice was originally about two-thirds of a mile in diameter, so it rarely produced enough material to generate large nighttime fireworks. But in 1995, SW3 collapsed, producing a large field of fragments that our planet is about to encounter.
When and where can I see the potential shower?
If the Tau Herculids do occur, they will be most visible in the lower 48 United States in the evening of Monday, May 30 and early in the morning of Tuesday, May 31, likely around 1 a.m. Eastern Time. The further south you live, the better your view. Skywatchers in West Africa, the Caribbean and South America are also favored to see some action. Those in high latitude places like Alaska are out of luck.
To shower, get away from bright city lights and find the darkest, lightest place possible, with a few hills or other obstacles on the horizon. The moon will be new that night, so its light will not interfere with the display. Allow about half an hour for your eyes to adjust to the darkness.
“The best gear is to go to your attic and pull out that beach chair,” said Joe Rao, associate astronomer at New York’s Hayden Planetarium. “So lay down and look up.”
Meteor showers appear to emanate from a point in the sky known as their radiant. The Tau Herculids, SW3’s meteor shower, were predicted to originate from the constellation of Hercules – hence the name of the shower – a prediction which has since been proven to be incorrect.
The Tau Herculids will actually originate from the constellation Boötes, beaming just above the star Arcturus, a red-orange-yellow entity that will be the brightest star in the Northern Hemisphere sky at this time. Locating Arcturus is easy if you can find the Big Dipper: Just draw a line from the last two stars in the handle of the Dipper in a direction away from its bowl. The first bright star you see should be Arcturus.
Unlike meteor showers that are visible days before and after a peak night, this show won’t last long, if it occurs at all.
“This is not a long-term event,” said Robert Lunsford, secretary general of the International Meteor Organization. “I would definitely try to get out at 10 a.m. PT or 1 a.m. EST because if nothing happens then it’s not an event.”
How many meteors could the Tau Herculids produce?
“That’s the $64,000 question,” Mr. Rao said. “There is no consensus. Predictions are absolutely everywhere.
NASA models are rather pessimistic, suggesting that few or potentially no meteors will be visible. But Mr Rao points to estimates from reputable meteor spotters at the opposite end of the spectrum who expect to see up to 10,000 meteors at 100,000 meteors per hour. If true, the Tau Herculids will be a meteor storm and possibly one of the greatest displays in recorded history.
“I’d be happy to see one in the hour,” Mr Lunsford said. “But there is a possibility that we could see one per second.”
Much will depend on the size and velocity of the debris as it hits the atmosphere and the size of the comet’s remaining particles.
“The particles can be the size of a grain of sand,” Rao said. “I maintain that there must be things out there at least as big as pebbles, or nuggets, or even the size of a ping-pong ball.”
If the fragments are smaller, they can produce many slow streaks that are too dark to be seen by the human eye. Night sky enthusiasts have already been burned at news of possible wonders like the supposedly unique sighting of Comet Kohoutek in 2020 that fell short of expectations.
“We had a lot of dark eyes predicting a wonderful event and then nothing happened,” Mr Lunsford said. “We need a certain set of circumstances for this meteor shower to happen, and the probability is low. But we owe it to the general public to let them know it’s a possibility.
Why could the Tau Herculids appear for the first time?
New meteor showers are rare events, Mr Lunsford said, “occurring only a few times a century”.
But in October 1995, astronomers began receiving phone calls from people claiming to have discovered a new comet, Rao said. The comet was not new: it was SW3 collapsing and becoming hundreds of times brighter than normal, he added.
“It was like breaking an egg,” he said. “All this dusty debris suddenly emerged.”
While our planet has bumped into pieces of dust from SW3 before, this will be the first time Earth’s orbit has encountered all of the material that erupted in 1995.
No one knows exactly what caused SW3 to collapse, but NASA’s Hubble and Spitzer Space Telescopes have observed the comet fragment for years. It was possible that the icy object had made too many passes close to both the scorching sun and Jupiter’s powerful gravitational pull.
“Perhaps after countless times when its orbit has been disrupted, it’s as if the comet finally said, ‘I can’t handle this anymore,’ and shattered into pieces,” Ms. Rao.
When did we learn what caused the meteor showers?
Humans have been spotting “shooting stars” for millennia. It is not known when ancient astronomers first associated them with a particular point in the sky. Mark Littman, author of “The Heavens on Fire: The Great Leonid Meteor Storms,” says some Native American traditions may point to an early understanding of radiants.
The Kiliwa, who are indigenous people of Baja California, Mexico, for example, describe meteor showers as a kind of fiery celestial urine from a constellation they call Xsmii.
“If you think of a meteor shower and you have, excuse me, the spray coming out, that suggests they noticed there was radiation,” Dr Littman said. “This would be the oldest sighting of a radiant we have.”
The oldest known written observation of a radiant came from Islamic skywatchers who recorded a large shower after the death of conqueror Abu Ishaq Ibrahim II ibn Ahmad in 902 AD. They noted that the meteors were coming from a location while they were raining down, Dr. Littman said.
Our modern understanding of meteor showers dates back to the late 18th century, when people noticed that a major comet passed a year before a major meteor storm headed for the constellation Leo. Then, on November 12, 1833, the Leonid Shower put on such a spectacular sight that thousands of shooting stars fell every minute.
“There have been reports of people falling to the ground in prayer and rushing to church to repent of their sins,” Dr Littman said.
Denison Olmsted, who was an astronomer in Connecticut, was awakened by his neighbors that night and came out to view the storm. Olmsted wrote to a local newspaper asking viewers to send him their own accounts, a request that was reprinted in newspapers across the country.
After collecting numerous responses and conducting further investigations, Olmsted concluded that the meteor showers originated from beyond our planet, contradicting a long-held belief expressed by Aristotle that meteors were exhalations from the surface. of the earth.
“He really should be considered the father of meteor science,” Dr Littman said.