The University of Hawaii’s NASA-funded telescopes have identified an asteroid the size of a car hurtling toward Earth — the first such discovery for a project designed as an early warning system and only the fourth time in history that an asteroid was seen prior to striking the planet.
The small asteroid is believed to have burned and broken up into pieces before falling into the Caribbean Sea south of Puerto Rico early Saturday morning, it was announced Tuesday.
Officials at the UH Institute for Astronomy were elated.
“It’s proof that the system works,” said Larry Denneau, co-principle investigator of the ATLAS telescopes.
Developed by the university and funded by NASA’s Near-Earth Object Observations program, ATLAS consists of two telescopes, one atop Mauna Loa on Hawaii island and the other on Haleakala on Maui. They automatically scan the whole sky several times every night looking for moving objects.
Since becoming operational in late 2016, the ATLAS telescopes have discovered 304 near-Earth asteroids, 33 potentially hazardous asteroids, 23 comets and 3,567 supernovae, according to the project’s website.
But the operation had yet to discover anything on a path to crash into Earth — until Saturday.
The 13-foot-diameter asteroid — later assigned the name 2019 MO — was observed four times over a 30-minute period by the ATLAS Mauna Loa facility around midnight Hawaii time Saturday.
At the time, officials said, the asteroid was only 311,oo miles from Earth — or 1.3 times the distance to the moon — and apparently headed our way.
The initial observations were analyzed by the NASA Jet Propulsion Laboratory’s Scout impact analysis software, and the asteroid was given a “modest” impact rating of 2 (its top rating of 4 is “likely”).
Then JPL also identified an atmospheric infrasound detection 12 hours later near Puerto Rico that could have matched the asteroid’s path.
Meanwhile, another NASA-funded and UH-run project on Haleakala, the Pan-STARRS 2 telescope, had imaged the part of the sky where 2019 MO should have been seen.
The asteroid was actually located on a part of the telescope’s camera that is not fully operational, but UH scientists Robert Weryk and Mark Huber, and Marco Micheli at the European Space Agency, were able to analyze the images and find the asteroid, according to the university.
With the additional observations, the asteroid’s predicted path was upgraded, and new calculations by the JPL software raised the impact rating to 4, or “likely.”
The improved orbit also matched the infrasound detection, and Nexrad weather radar in Puerto Rico spotted the asteroid as it burned in the atmosphere over the ocean about 236 miles south of San Juan, which was near the infrasound location.
Denneau said it’s believed that only a few asteroids of similar size are thought to enter Earth’s atmosphere a year.
Another asteroid of similar size was discovered before impact three weeks ago by the Catalina Sky Survey telescope, a NASA-funded survey observatory near Tucson, Ariz. The same team made similar discoveries in 2008 and 2014.
Denneau said ATLAS is on the lookout for even larger space objects. The larger the objects, the more they reflect sunlight, which makes them easier to identify and provide sufficient warning to move people away from an incoming asteroid’s impact site.
The project will provide one day’s warning for a 30-kiloton “town killer,” a week for a 5-megaton “city killer” and three weeks for a 100-megaton “county killer,” according to the ATLAS website.
Correction: The asteroid identified by University of Hawaii’s telescopes was observed when it was about 311,000 miles from Earth, not 310 miles, as was reported in an earlier version of this story and in the Wednesday’s print edition.
