NASA accurately predicted the impact of a small asteroid on Earth

The small two-meter asteroid  hit the atmosphere over the Norwegian Sea on April 11. It was discovered just two hours before impact.

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Astronomers have been able to predict exactly where and when a small asteroid would hit the atmosphere over the Norwegian Sea before disintegrating on March 11, 2022.

Two hours before the asteroid hit, K. Sarneczky of the Piszkésteto Observatory in northern Hungary first reported observations of small object 2022 EB5 to the Minor Planet Center, the internationally recognized clearinghouse for measurements. position of small celestial bodies. The object was posted on the Minor Planet Center’s Near-Earth Object Confirmation page to flag it for additional observations that would confirm it as a previously unknown asteroid .

NASA ‘s “Scout” impact risk assessment system took these first measurements to calculate the trajectory of 2022 EB5 . As soon as Scout determined that 2022 EB5 was going to hit Earth’s atmosphere, the system alerted the Center for Near-Earth Object Studies (CNEOS) and NASA ‘s Planetary Defense Coordination Office , and marked the object on the Scout web page to notify the observing community of the nearby object.

Maintained by CNEOS at NASA ‘s Jet Propulsion Laboratory in Southern California, Scout automatically searches the Minor Planet Center’s database for possible new near-term impactors. CNEOS calculates all known orbits of near-Earth asteroids to improve impact risk assessments in support of the Planetary Defense Coordination Office.

“Scout had just 14 observations over 40 minutes from one observatory to work with when he first identified the object as an impactor. We were able to determine the possible impact locations, which initially ranged from western Greenland to the coast of Norway,” he said. in a statement Davide Farnocchia, a navigation engineer at JPL who developed Scout. “As more observatories tracked the asteroid, our calculations of its trajectory and impact location became more precise.”

to great precision

Scout determined that 2022 EB5 would enter the atmosphere southwest of Jan Mayen, a Norwegian island nearly 300 miles off the east coast of Greenland and northeast of Iceland. At 22:23 UTC, 2022 EB5 hit the atmosphere as predicted by Scout, and infrasound detectors confirmed that the impact occurred at the predicted time.

From observations of the asteroid as it approached Earth and the energy measured by infrasound detectors at the time of impact, 2022 EB5 is estimated to have been about 2 meters in size. Small asteroids of this size become bright enough to be detected only in the last few hours before their impact (or before they come very close to Earth). They are much smaller than the objects that NASA commissions the Planetary Defense Coordination Office to detect and warn about.

“Tiny asteroids like 2022 EB5 are numerous and impact the atmosphere quite frequently, about every 10 months,” said Paul Chodas, director of CNEOS at JPL. “But very few of these asteroids have actually been detected in space and widely observed before impact, basically because they are very faint until the last few hours, and a survey telescope has to look at the right place in the sky at the right time for one. to be detected.”

A larger asteroid with dangerous impact potential would be discovered much farther from Earth. NASA ‘s goal is to track such asteroids and calculate their trajectories so as to have many years’ notice of a potential impact should one be identified. But this real-world event with a very small asteroid allowed the planetary defense community to exercise capabilities and gave some confidence that the impact prediction models at CNEOS are highly capable of informing the potential impact response of a larger object.

2022 EB5 is only the fifth small asteroid to be detected in space before hitting Earth’s atmosphere. The first asteroid discovered and tracked long before it collided with Earth was 2008 TC3, which entered the atmosphere over Sudan and disintegrated in October 2008. That 4-meter-wide asteroid scattered hundreds of small meteorites over the Nubian Desert. As surveys become more sophisticated and sensitive, more of these harmless objects will be detected before they enter the atmosphere. (EuropePress).