A bright fireball may have dropped meteorites in the Niagara region


A bright fireball may have dropped meteorites in the Niagara region

Time-lapse image of the fireball event from start to finish. Credit: Western Meteor Group

A cosmic drama unfolded over southern Ontario on Friday night, November 18, leading to an international collaboration and a meteor hunt. Just before midnight ET, the Catalina Sky Survey in Arizona detected a small object heading toward Earth.

This small asteroid, now designated 2022 WJ1, was followed by several observatories around the world over the next three hours before crashing into southern Ontario at 3:26 a.m. EDT on November 19.

The few hours of advance warning about asteroid impact Several members of the Western Meteor Physics Group and the Institute for Earth and Space Exploration were allowed to move outside and find clear weather to view the incoming object.

David Clarke, a doctoral student in geophysics, drove to the projected fall area in the early morning hours and was able to see fireball With his own eyes, parked near Niagara-on-the-Lake at the intersection of Highway 403 and Niagara Regional Route 55 (formerly Highway 55).

“It went right over the head at the expected time and was visibly green,” Clark said. A few minutes later, a noticeable boom was heard.

A view of the fireball from the Hume Cronin Memorial Observatory at Western University. Credit: University of Western Ontario

Physics and astronomy professor Paul Wigert was also alerted early enough to see the fireball.

“I watched from Brescia Hill on the West Campus. Although cold and windy, the hill had a clear view to the east, where I had expected to see only a distant flicker. Then the ball of fire suddenly appeared, passing almost over our heads. Wonderful! Easily seen Among the broken clouds, the red-orange is noticeably visible.

The bright fireball from terminal descent of 2022 WJ1 was also observed by the All-Sky Camera Network across southern Ontario at 03:26 a.m. on November 19, just as expected. The meteor entered Earth’s atmosphere just south of Woodstock, heading east as a bright fireball almost to its end at an altitude of 20 kilometers north of the city of Vinland.

Analysis of the video data, also captured by cameras provided by Curtin University (Australia) within the Western Network, indicates that fragments of the meteorite likely reached Earth near the southern shore of Lake Ontario, primarily north of St. Catharines.

A bright fireball may have dropped meteorites in the Niagara region

Map of the fireball’s ground trajectory to its end point (marked with a black ‘x’). Other points refer to some of the All-Sky Camera Network locations that observed the fireball. Credit: University of Western Ontario

“This fireball is particularly important as the parent meteorite was observed telescopically before it hit the atmosphere,” Peter said. “This makes it a rare opportunity to correlate telescopic data from an asteroid with its atmospheric implosion behavior to gain insight into its internal structure.” Brown, Canada Research Chair in Minor Planetary Objects at Western.

Only six other asteroids in history have been given advance warning of their impact, with all cases detected just hours before they entered the atmosphere. This is the first event expected to occur in a densely populated area and within a suite of instruments dedicated to measuring fireball.

A bright fireball may have dropped meteorites in the Niagara region

Credit: Google Earth

Despite extensive cloud cover in southern Ontario during that period, six cameras in the All-Sky Camera Network detected the fireball along with western Canadian Meteor Orbit radar, providing an unprecedented record of this small asteroid’s disintegration in the atmosphere.

“This remarkable event will provide clues about composition and strength that when combined with telescopic measurements will inform our understanding of how small asteroids break through the atmosphere, which is important knowledge for planetary defence,” Brown said.

The last piece in this cosmic puzzle is the recovery of meteorites associated with fireball 2022 WJ1 and the researchers are asking for public help. Those in the area between Port Wheeler and Virgil in particular should be on the lookout.

“We know from camera records and weather radar that tracked debris falling from the fireball that meteorites most likely made it to Earth near or east of Grimsby. What we need now to complete this story is recover some of these rocks and find out what type of material Asteroid 2022 WJ1 is made of,” he said. Brown. “This is very much like a returning space mission, but in this case the sample fell on us.”

Meteorites can be identified by their dark, often scalloped exterior, which is a fusional crust no more than a millimeter deep, covering a stony-gray interior. They are usually denser than “normal” rocks and are often attracted to magnets because of their mineral content. Meteorites are not dangerous, but if recovered, it is best to put them in a clean plastic bag or wrap them in aluminum foil. It should also be handled as little as possible to help preserve its scientific value. In Canada, meteorites belong to the owner of the land on which they were found. If individuals intend to search, they must always obtain permission from the landowner before venturing onto private land.

more information:
Researchers at Western and the Royal Ontario Museum are interested in hearing from anyone in the area of ​​the potential fall who might have heard anything unusual, or who might have stumbled upon possible meteorites. If you believe you have found a suspicious rock from this event, please contact the Royal Ontario Museum at naturalhistory@rom.on.ca.

the quote: Bright Fireball May Have Dropped Meteorites in Niagara Region (2022, November 22) Retrieved November 23, 2022 from https://phys.org/news/2022-11-bright-fireball-meteorites-niagara-region.html

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