Scientists Reveal a New Way to Study Near-Earth Asteroids

A timelapse image of the fireball event from start to finish. Credit: Western Meteor Group

On November 18th, 2022, shortly before midnight, the Catalina Sky Survey (CSS) in Arizona and other observatories worldwide detected a small object (now designated 2022 WJ1) heading toward Earth. For the next three hours, the CSS and the Southern Ontario Meteor Network (SOMN) at the University of Western Ontario monitored the object before it entered Earth’s atmosphere above Southern Ontario. At 03:26 a.m. EST (12:26 a.m. PST) on November 19th, the object appeared as a bright fireball that scattered meteorite fragments across the Niagara region.

This event triggered an international collaboration to hunt down the fragments for analysis, but none have been found yet. In a recent study led by Western University and Lowell Observatory, an international team of scientists described a new approach for studying near-Earth asteroids (NEA) based largely on 2022 WJ1. The study is significant in that the team determined the NEA’s composition—the smallest asteroid characterized to date—and established a new and integrated methodology for studying other NEAs that may impact Earth someday.

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Space Force is Releasing Decades of Tracking Data on a Thousand Bright Meteor Fireballs

Bright Fireball Credit: Adrian West

When a meteoroid enters the Earth’s atmosphere at a very high speed it heats up. This heating up produces a streak of light and is termed a meteor. When a meteor is bright enough, about the brightness of Venus or brighter, it becomes a fireball. Sometimes these fireballs explode in the atmosphere, becoming bolides. These bolides are bright enough to be seen even during the day.

Studying bolides as they pass through the atmosphere can help model larger asteroids, something of interest to the Planetary Defense Coordination Office (PDCO) which is run by NASA. These asteroids can be deadly if they are large enough, and learning how to predict their behavior is essential to protecting our planet from a devastating impact with long-term implications for the survival of many species on Earth.

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Satellites Watched a Huge Fireball Explode Above the Bering Sea Late Last Year

NASA's MODIS instrument, aboard the Terra satellite, captured this true-color image showing the remnants of a meteor's passage, seen as a dark shadow cast on thick, white clouds on Dec. 18, 2018. Credit: NASA GSFC

When a meteor strike the Earth’s atmosphere, a magnificent (and potentially deadly) explosion is often the result. The term for this is “fireball” (or bolide), which is used to describe exceptionally bright meteor explosions that are bright enough to be seen over a very wide area. A well-known example of this is the Chelyabinsk meteor, a superbolide that exploded in the skies over a small Russian town in February of 2013.

On December 18th, 2018, another fireball appeared in the skies over Russia that exploded at an altitude of about 26 km (16 mi) above the Bering Sea. The resulting debris was observed by instruments aboard the NASA Terra Earth Observation System (EOS) satellite, which captured images of the remnants of the large meteor a few minutes after it exploded.

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