A 6.5-foot-wide asteroid smacked into Earth's atmosphere on March 11, and NASA said thanks to an excellent planetary defense game plan, they were able to predict precisely where and when it would happen.
Asteroid 2022 EB5 was too small to threaten Earth and disintegrated over the Norwegian Sea after it hit Earth's atmosphere.
Here's how NASA explains astronomers could determine where and when the asteroid would hit.
It all started with the first observation of the asteroid by the Piszkéstető Observatory in Hungary about two hours before impact. That report was sent to the Minor Planet Center and flagged for additional observations worldwide to confirm it was an unknown asteroid.
NASA's "Scout" impact hazard system at NASA's Jet Propulsion Laboratory in California automatically searches the Minor Planet Center's database for possible fast-approaching impacts. Scout used early measurements to calculate the trajectory of Asteroid 2022 EB5 and determined it would hit Earth's atmosphere. This information was then sent to the Center for Near Earth Object Studies and NASA's Planetary Defense Coordination Office.
"Scout had only 14 observations over 40 minutes from one observatory to work with when it first identified the object as an impactor. We were able to determine the possible impact locations, which initially extended from western Greenland to off the coast of Norway," said Davide Farnocchia, the JPL navigation engineer who developed Scout. "As more observatories tracked the asteroid, our calculations of its trajectory and impact location became more precise."
Sure enough, Scout determined that 2022 EB5 would enter the atmosphere southwest of the Norwegian island Jan Mayen at 5:23 p.m. EST. NASA said in a news release that infrasound detectors confirmed the impact happened as predicted.
From two hours to impact may not sound like a lot of time, but NASA asteroid experts said Earth is hit by small asteroids like 2022 EB5 all the time.
Paul Chodas, the director of the Center for Near Earth Object Studies at JPL, said these small impacts happen roughly every 10 months. A larger asteroid would be discovered much farther from Earth. What makes this rare is that 2022 EB5 is only the fifth small asteroid to be found in space before crashing into Earth’s atmosphere.
"Very few of these asteroids have actually been detected in space and observed extensively prior to impact, basically because they are very faint until the last few hours, and a survey telescope has to observe just the right spot of sky at the right time for one to be detected," Chodas explained.
NASA said this small asteroid was a good test for the planetary defense community to show it's highly capable of predicting impacts.
If a giant asteroid was headed for our planet, NASA and its international partners are working on a plan to deflect a potential city-killer asteroid.
NASA launched the DART spacecraft in November to test out an Earth-defense plan. This fall, the spacecraft will act as a battering ram, crashing into the surface of Dimorphos, a small moonlet of the asteroid called Didymos.
DART won't change the orbit of Didymos. It aims to change the speed of the moonlet, Dimorphos. This is because scientists using ground-based telescopes and later another spacecraft will launch to the asteroids to check DART's impact area.
If this works, the idea is to apply the same technique to larger asteroids.