You may see a new meteor shower in the night sky, or nothing at all


The breakup of a comet three decades ago could trigger a rarely seen meteor storm on Monday night. Or it could be a complete dud.

A Perseid meteor shower shone into Spruce Knob, W.Va last year. Most meteor showers occur when the Earth collides with debris from a comet. Bill Ingalls/NASA via AP

A never-before-seen meteor shower can illuminate the sky with untold numbers of dazzling streaks from Monday night through early Tuesday east.

Or the event could spiral out of control and be a dud.

Those are the best predictions meteor observers have for the Tau Herculids, a potentially celestial spectacle that will thrill sky-gazing enthusiasts.

Meteor showers can occur when Earth plows into debris produced by a comet (or, occasionally, asteroids). The source of the Tau Herculids is comet 73P/Schwassmann-Wachmann 3, or SW3. 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 fragment field that our planet is about to meet.

When and where can I see the potential shower?

If the Tau Herculids do happen, they will be most visible in the contiguous United States Monday evening through early Tuesday, likely around 1 a.m. Eastern. The further south you live, the better your view. Skywatchers in West Africa, the Caribbean and South America also prefer to see some action. Those in places in high latitudes like Alaska are out of luck.

To catch the shower, move away from bright city lights and find the darkest and brightest location you can, one with few hills or other obstacles on the horizon. The moon will be new that night, so its light won’t interfere with the view. Give your eyes about half an hour to get used to the darkness.

“The best device is to go up to your attic and drag that beach chair out,” said Joe Rao, an astronomer at the Hayden Planetarium in New York City. “Then just lie back and look up.”

Meteor showers appear to originate from a point in the sky known as their radiant. The Tau Herculids were predicted to come from the constellation Hercules — hence the shower’s name — a prediction that has since been proven wrong.

The Tau Herculids will actually come from the constellation of Boötes, radiating from just above the star Arcturus, a ruddy orange-yellow entity that will be the brightest star in the Northern Hemisphere’s sky at the time. Locating Arcturus is easy if you can find the Big Dipper: just draw a line from the last two stars in the Dipper’s handle in a direction away from the bowl. The first bright star you see should be Arcturus.

Unlike meteor showers that are visible for days before and after a peak night, this show won’t last long, if at all.

“This is not a long-term event,” said Robert Lunsford, secretary general of the International Meteor Organization. “I would definitely try to be out by 10 a.m. Pacific Time or 1 a.m. Eastern because if nothing happens then it’s a non-event.”

How many meteors can the Tau Herculids produce?

“That’s the $64,000 question,” Rao said. “There is no agreement. The predictions are absolutely all over the place.”

NASA models are on the pessimistic side, suggesting few, if any, meteors will be visible. But Rao points to estimates from renowned meteor observers at the other end of the spectrum who predict they’ll see as many as 10,000 to 100,000 meteors per hour. If true, the Tau Herculids will be a meteor storm and possibly one of the biggest displays in recorded history.

“I’d be happy to see one on the hour,” Lunsford said. “But there’s a possibility we could see one every second.”

Much will depend on the size and speed of the debris as it hits the atmosphere and how large the comet’s leftover particles are.

“The particles can be the size of a grain of sand,” Rao said. “I maintain that there must be things at least the size of pebbles, or nuggets, or even the size of a ping pong ball.”

If the fragments are on the small side, they can produce many slow streaks that are too faint for the human eye to see. Night sky supporters have been burned before announcing possible miracles, such as the supposedly once-in-a-lifetime observation of Comet Kohoutek in 1974 that fell short of expectations.

“We got a lot of black eyes when predicting a great event, and then nothing happens,” said Lunsford. “We need a certain set of conditions for this meteor shower to occur, and the chances are slim. But we owe it to the general public to let them know that this is a possibility.”

Why would the Tau Herculides appear for the first time?

New meteor showers are rare events, Lunsford said, “only happens a few times a century.”

But in October 1995, astronomers started getting calls from people claiming to have discovered a new comet, Rao said. The comet wasn’t new: It was SW3 that broke apart and became hundreds of times brighter than normal, he said.

“It was like breaking an egg,” he said. “All this dusty debris suddenly popped up.”

Although our planet has already hit bits of dust from SW3, this will be the first time Earth’s orbit has encountered all the material that erupted in 1995.

No one knows exactly what caused SW3’s collapse, but NASA’s Hubble and Spitzer space telescopes watched the comet’s fragment for years. It was possible that the icy object was making too many dense passes to both the sun and Jupiter’s powerful gravitational pull.

“Maybe after numerous times of its orbit being disrupted, it’s as if the comet finally said, ‘I can’t handle this anymore,’ and broke into pieces,” Rao said.

When did we learn what caused meteor showers?

People have been spotting ‘shooting stars’ for thousands of years. It is not known when ancient skygazers first associated them with a particular point in the sky. Mark Littmann, 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, indigenous people of Baja California, Mexico, for example, describe meteor showers as a kind of fiery celestial urine emanating from a constellation they call Xsmii.

“If you think of a meteor shower, and you have, excuse me, the spray that comes out suggests they noticed there was a radiant,” Littmann said. “That would be the oldest observation of a radiant we have.”

The oldest known written sighting of a radiant came from Muslim sky watchers who recorded a major downpour after the death of conqueror Abu Ishaq Ibrahim II ibn Ahmad in 902. They noticed the meteors came from one spot as they rained, Littmann said.

Our modern understanding of meteor showers can be traced back to the late 1700s, when people saw a great comet pass by a year before a major meteor storm from the direction of the constellation Leo. Then, on November 12, 1833, the Leoniden shower was rendered so spectacular that thousands of shooting stars fell every minute.

“There were reports of people falling to the ground in prayer and rushing to church to repent of their sins,” Littmann said.

Denison Olmsted, an astronomer in Connecticut, was woken that night by his neighbors and went outside to watch the storm. Writing to a local newspaper, Olmsted asked viewers to send him their own bills, a request that was reprinted in newspapers across the country.

After collecting many answers and doing further research, Olmsted concluded that meteor showers originate outside our planet, contradicting Aristotle’s long-held belief that meteors were exhalations from the Earth’s surface.

“He really should be the father of meteor science,” Littmann said.

This article originally appeared in The New York Times.

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