NASA originally published this article on November 22, 2022.
NASA predicted asteroid affect
2022 WJ1 was a tiny asteroid on a collision course with Earth. However astronomers noticed it coming, and NASA’s Scout affect hazard evaluation system calculated the place it could hit.
Within the early hours of Saturday, November 19, 2022, the skies over southern Ontario, Canada, lit up as a tiny asteroid harmlessly streaked throughout the sky excessive in Earth’s environment, broke up, and certain scattered small meteorites over the southern shoreline of Lake Ontario. The fireball wasn’t a shock. Roughly 1 meter (3 toes) broad, NASA detected the asteroid 3 ½ hours earlier than affect, making this occasion the sixth time in historical past a small asteroid has been tracked in space earlier than impacting Earth’s environment.
One in all NASA’s duties is to detect and observe the bigger near-Earth objects that would survive passage via Earth’s environment and trigger injury on the bottom, however these objects will also be detected a lot additional prematurely than small ones just like the asteroid that disintegrated over southern Ontario. Such small asteroids are usually not a hazard to Earth, however they could be a helpful check for NASA’s planetary protection capabilities for discovery, monitoring, orbit dedication, and affect prediction.
Planetary protection
Kelly Fast, Close to-Earth Object Observations program supervisor for the Planetary Protection Coordination Workplace (PDCO) at NASA Headquarters in Washington, mentioned:
The planetary protection group actually demonstrated their ability and readiness with their response to this short-warning occasion. Such innocent impacts change into spontaneous real-world workout routines and provides us confidence that NASA’s planetary protection methods are able to informing the response to the potential for a severe affect by a bigger object.
The NASA-funded Catalina Sky Survey in Tucson, Arizona, found the asteroid on the night of November 18, throughout routine search operations for near-Earth objects. The observations had been rapidly reported to the Minor Planet Center – the internationally acknowledged clearinghouse for the place measurements of small celestial our bodies – and the information was then robotically posted to the Near-Earth Object Confirmation Page.
NASA’s Scout impact hazard assessment system, which is maintained by the Middle for Close to Earth Object Research (CNEOS) on the company’s Jet Propulsion Laboratory in Southern California, robotically fetched the brand new information from that web page and commenced calculating the article’s potential trajectory and probabilities of affect. CNEOS calculates each recognized near-Earth asteroid orbit to supply assessments of potential affect hazards in help of NASA’s PDCO.
Go to the absolutely interactive Eyes on Asteroids website.
Collaboration was key
Seven minutes after the asteroid was posted on the affirmation web page, Scout had decided it had a 25% chance of hitting Earth’s environment, with potential affect areas stretching from the Atlantic Ocean off the East Coast of North America to Mexico. Extra observations had been then offered by the astronomical group, together with beginner astronomers in Kansas, to raised refine the asteroid’s trajectory and potential affect location.
Shantanu Naidu, navigation engineer and Scout operator at JPL, mentioned:
Small objects similar to this one can solely be detected when they’re very near Earth, so if they’re headed for an affect, time is of the essence to gather as many observations as potential. This object was found early sufficient that the planetary protection group may present extra observations, which Scout then used to verify the affect and predict the place and when the asteroid was going to hit.
As Catalina continued to trace the asteroid over the subsequent few hours, Scout used this new information to repeatedly replace the asteroid’s trajectory and the system’s evaluation of the prospect of affect, posting these outcomes on the hazard-assessment system’s webpage.
Neighborhood effort helped verify the asteroid affect
Many astronomers verify the Scout webpage all through the evening to find out an important asteroids to trace. A gaggle of beginner astronomers at Farpoint Observatory in Eskridge, Kansas, tracked the asteroid for greater than an hour, offering important further information that enabled Scout to verify a 100% affect chance and decide the anticipated location of atmospheric entry as being over southern Ontario at 3:27 a.m. EST (12:27 a.m. PST) November 19. With greater than two hours remaining earlier than affect, there was time to alert scientists in southwestern Ontario of the intense fireball that will happen.
A total of 46 observations of the asteroid’s place had been in the end collected, the ultimate one being made solely 32 minutes earlier than affect by the University of Hawaii 88-inch (2.2-meter) telescope on Mauna Kea.
As predicted, at 3:27 a.m. EST (12:27 a.m. PST), the asteroid streaked via Earth’s environment at a shallow angle and broke up, probably producing a bathe of small meteorites and leaving no reported injury on the floor. After this innocent disintegration, the Minor Planet Middle designated the asteroid 2022 WJ1 to acknowledge its discovery whereas nonetheless in space.
Many sightings
Dozens of sightings had been reported to the American Meteor Society, and scientists who had been alerted to the Scout prediction had been capable of {photograph} the asteroid’s atmospheric entry. Movies of the fireball collected by the general public had been additionally posted on-line. NASA’s Meteorite Falls website additionally reported climate radar detections of fragments of the fireball falling as meteorites on the predicted time over Lake Ontario. Small meteorites could be discovered east of the city of Grimsby whereas bigger meteorites could be nearer the city of McNab.
The primary asteroid to be found and tracked effectively earlier than hitting Earth was 2008 TC3, which entered the environment over Sudan and broke up in October 2008. That 13-foot-wide (4-meter-sized) asteroid scattered a whole bunch of small meteorites over the Nubian Desert. Earlier this yr, asteroid 2022 EB5 entered the environment over the Norwegian Sea after Scout precisely predicted its location, changing into the fifth object to be detected earlier than affect. As surveys change into extra refined and delicate, extra of those innocent objects are being detected earlier than coming into the environment, offering actual workout routines for NASA’s planetary protection program.
Backside line: NASA predicted the asteroid affect in Ontario, Canada, with its Scout affect hazard evaluation system. The objective of Scout is to trace affect hazards to Earth.
