Olympic Pool-Sized Asteroid Has ‘Very Small Chance of Impacting Earth’, NASA Says

An asteroid about the size of an Olympic swimming pool currently has a 1-in-625 chance of impacting Earth on February 14, 2046, according to a risk list managed by the European Space Agency’s Near Earth Objects Coordination Centre, which monitors space rocks that might be potentially hazardous to Earth.

Though this is a relatively high risk of an impact, it is far more likely that this asteroid, known as 2023DW, will miss our planet on Valentine’s Day that year. The asteroid was discovered just a little over a week ago, on February 27, and scientists are still working out key details about its size, shape, and orbital characteristics that will determine if the rock is a real threat.

“We've been tracking a new asteroid named 2023 DW that has a very small chance of impacting Earth in 2046,” said NASA’s Planetary Defense Coordination Office, which detects and monitors asteroids and other space objects, in a tweet on Tuesday. 

“Often when new objects are first discovered, it takes several weeks of data to reduce the uncertainties and adequately predict their orbits years into the future. Orbit analysts will continue to monitor asteroid 2023 DW and update predictions as more data comes in.”

At an estimated 160-feet across, 2023DW would not deliver the kind of punch to Earth that wiped out the non-avian dinosaurs 66 million years ago, as that ancient object likely had a diameter of several miles. 

However, 2023DW is about twice as big as the object that exploded over the skies of Chelyabinsk, Russia, in 2013, producing a powerful shockwave that shattered windows, damaged buildings, and caused multiple injuries on the ground. An impactor twice as big as the Chelyabinsk could be very dangerous on a regional level, especially if it impacted a populated area.

Piero Sicoli, an astronomer who specializes in near-Earth objects at the Italian Sormano Astronomical Observatory, sketched out a rough estimate of where 2023DW might hit our planet, based on what we know about the rock at this point. 

His preliminary results reveal a potential impact zone that stretches across the continental United States and through much of Southeast Asia, though he cautioned that the map is only an exercise that will probably be ruled out as new observations come in.

“[T]hanks to the computational speed of computers, it is now possible to process

tens of thousands of orbit-clones and thus estimate how many solutions lead to an impact,” Sicoli said. “In the specific case of my graph, for example, I have processed almost 65,000 different possible orbits of  2023 DW and only 150 of these indicate an impact” meaning that there is a “99.77% chance the asteroid will miss the Earth.”

“With the current data (updated to 8 March 2023) one can only say that on 14 February 2046 the asteroid will pass at an Earth-distance between zero and just under two million km (5 times the distance to the Moon),” he noted.

The worldwide planetary defense community has been preparing for the possibility that a space rock might hit Earth, though there is no serious risk of such a collision at this time. Last year, NASA’s Double Asteroid Redirection Test (DART) successfully changed the orbit of a small asteroid orbiting a slightly larger rock, demonstrating that it is possible to nudge dangerous objects into new trajectories if there is enough lead time. NASA and FEMA have also developed evacuation plans for regions that might be in the blast zone of an incoming space rock.

Sicoli said that it is difficult to predict the fallout of 2023 DW, on the off chance it impacts Earth, because it depends on the asteroid’s exact size, composition, and collision angle, among many other factors.

“Generally speaking, it can be said that for asteroids of this size there would certainly be some damage, however limited to the fall zone only,” he concluded. “Given the percentages mentioned above, however, we can say that there is no cause for concern.”

Update: This article has been updated to include comments from astronomer Piero Sicoli.