A fireball lit up the skies of Ontario on November 19, 2022. NASA predicted the asteroid impact with its Scout impact hazard assessment program. Image via NASA/Robert Weryk.
This article was originally published by NASA on November 22, 2022.
NASA predicted an asteroid impact
2022 WJ1 was a small asteroid on a collision course with Earth. But astronomers saw it coming, and NASA’s Scout Impact Hazard Assessment System calculated where it would land.
In the early hours of Saturday, November 19, 2022, the skies of southern Ontario, Canada lit up as a small asteroid hurtled harmlessly through the sky high in Earth’s atmosphere, broke up and probably scattered small meteorites along the southern shore of the lake. Ontario. The fireball was no surprise. About 1 meter (3 feet) across, NASA spotted the asteroid 3 1/2 hours before impact, making this event the sixth time in history that a small asteroid has tracked into the space before impacting the Earth’s atmosphere.
One of NASA’s jobs is to detect and track larger near-Earth objects that could survive passage through Earth’s atmosphere and cause damage to the ground, but these objects can also be detected much earlier than small like the asteroid that disintegrated in the south. Ontario. These small asteroids are not a danger to Earth, but they can be a useful test for NASA’s planetary defense capabilities for discovery, tracking, orbit determination, and impact prediction.
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planetary defense
Kelly Fast, Near-Earth Object Observation Program Manager for the Planetary Defense Coordination Office (PDCO) at NASA Headquarters in Washington, said:
The planetary defense community truly demonstrated their ability and readiness with their response to this short notice event. These harmless impacts become spontaneous real-world exercises and give us confidence that NASA’s planetary defense systems are capable of informing the response to the possibility of a serious impact by a larger object.
The NASA-funded Catalina Sky Survey in Tucson, Arizona, discovered the asteroid on the night of November 18, during routine search operations for near-Earth objects. The observations were quickly reported to the Minor Planet Center, the internationally recognized clearinghouse for position measurements of small celestial bodies, and the data was automatically posted to the Near-Earth Object Confirmation page.
NASA’s Scout impact hazard assessment system, maintained by the Center for Near Earth Object Studies (CNEOS) at the agency’s Jet Propulsion Laboratory in Southern California, automatically obtained the new data from this page and began to calculate the possible trajectory and impact possibilities of the object. . CNEOS calculates all known near-Earth asteroid orbits to provide assessments of potential impact hazards in support of NASA’s PDCO.
Visit the fully interactive Eyes on Asteroids site.
Collaboration was key
Seven minutes after the asteroid was posted on the confirmation page, Scout had determined it had a 25% chance of hitting Earth’s atmosphere, with potential impact sites stretching from the Atlantic Ocean to the east coast of North America to Mexico. The astronomical community then provided more observations, including amateur astronomers in Kansas, to better refine the asteroid’s trajectory and possible impact location.
Shantanu Naidu, JPL’s navigation engineer and scout operator, said:
Small objects like this can only be detected when they are very close to Earth, so if they are headed for an impact, time is of the essence to collect as many observations as possible. This object was discovered early enough that the planetary defense community could provide further observations, which Scout used to confirm the impact and predict where and when the asteroid was going to hit.
As Catalina continued to track the asteroid over the next few hours, Scout used this new data to continuously update the asteroid’s trajectory and the system’s assessment of the possibility of impact, posting these results to the system’s web page hazard assessment.
The community effort helped confirm the asteroid impact
Many astronomers check the Scout website throughout the night to determine the most important asteroids to track. A group of amateur astronomers at the Farpoint Observatory in Eskridge, Kansas, tracked the asteroid for more than an hour, providing critical additional data that allowed Scout to confirm a 100 percent impact probability and determine the predicted location of atmospheric entry as over southern Ontario at 3:27 am EST (12:27 am PST) November 19. With more than two hours to go before impact, there was time to alert scientists in southwestern Ontario to the bright fireball that was about to occur.
Ultimately, a total of 46 observations of the asteroid’s position were collected, the last of which was made just 32 minutes before impact by the University of Hawaii’s 88-inch (2.2-meter) telescope at Mauna Kea.
As predicted, at 3:27 a.m. EST (12:27 a.m. PST), the asteroid crossed Earth’s atmosphere at a shallow angle and broke up, likely producing a shower of small meteorites and leaving no surface damage. After this harmless disintegration, the Minor Planet Center designated asteroid 2022 WJ1 to recognize its discovery while it was still in space.
Lots of sightings
Dozens of sightings were reported to the American Meteor Society, and scientists who were alerted to the scout’s prediction were able to photograph the asteroid’s atmospheric entry. Videos of the fireball collected by the public were also uploaded online. NASA’s Meteorite Falls website also reported weather radar detections of fireball fragments falling as meteorites at the predicted time over Lake Ontario. Small meteorites could be found east of the town of Grimsby, while larger meteorites could be closer to the town of McNab.
The first asteroid to be discovered and tracked long before it hit Earth was 2008 TC3, which entered the atmosphere over Sudan and broke up in October 2008. That 13-foot-wide asteroid ( 4 meters) scattered hundreds of small meteorites over the Nubian Desert. Earlier this year, asteroid 2022 EB5 entered the atmosphere over the Norwegian Sea after Scout accurately predicted its location, becoming the fifth object to be detected before impact . As surveys become more sophisticated and sensitive, more of these harmless objects are detected before they enter the atmosphere, providing real-world exercises for NASA’s planetary defense program.
Conclusion: NASA predicted an asteroid impact in Ontario, Canada with its Scout Impact Hazard Assessment System. Scout’s purpose is to track impact hazards on Earth.
Read more: Asteroid hit Canada, may have dropped meteorites
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