In November 2022, a fireball called 2022 WJ1 exploded over Niagara Falls. Based on the data obtained at that time, scientists were able to determine its parameters. It turned out to be the smallest among those that could be properly seen.
Fireball over Niagara Falls
On November 19, 2022, a fireball exploded over Niagara Falls. This is the name given to the phenomenon when a large space rock enters the dense layers of the Earth’s atmosphere and turns into a fireball.
Then this event, despite the noise it made, was not a surprise to scientists. In fact, astronomers had noticed asteroid 2022 WJ1 a few days earlier. Almost immediately, it became clear that it was headed for a collision with Earth. At the same time, the danger was determined to be minimal because, at its approximate size and approach angle, it should not have reached the Earth.
A little later, it became clear that the collision would occur in the Great Lakes region of North America. Therefore, all the automatic cameras monitoring the skies in the area were prepared to watch the show. Therefore, it was possible to view the fireball from several points during the fall.
The study by scientists from Western University and the Lowell Observatory is based on these observations. They discovered the size of 2022 WJ1 and the material it consisted of.
The smallest asteroid
Research was done by comparing data obtained while the rock was in space with data obtained when it fell. It was thanks to them that scientists learned that the body was only 40 to 60 centimeters in diameter.
This makes it the smallest asteroid ever studied in such detail. It may look strange, but such a small body can really be called that. The fact is that the alternative term “meteoroid” never caught on, and there is no lower bound for the size of asteroids anyway.
This is only the second time that an asteroid that has impacted Earth has been characterized by telescopes before the event occurred. In addition to size, the chemical composition of the space rock was determined. It turned out that it consisted mainly of silicon.
Provided by phys.org
