NASA monitoring asteroid that may crash into Earth on Valentine’s Day 2046 — but they’re not too worried about it
An Olympic-pool-sized asteroid discovered less than two weeks ago has one of the greatest chances of crashing into Earth than any we're currently monitoring.
Named 2023DW, the asteroid was first discovered Feb. 26 by a Chilean observatory and is anticipated to make impact two decades from now on Valentine's Day 2046, according to the European Space Agency (ESA).
That said, experts believe the discovery is no major cause for concern.
Hanno Rein, an associate professor of astronomy and astrophysics at the University of Toronto, said current best estimates put 2023DW as having a one in 600 chance of impact with Earth.
Although scientists are still studying the object and predictions may change with time, Rein said, Given its size, and given its relatively low probability, there's really no cause for concern at the moment."
If the probability increases, going up to one in 100 or one in 10, then it becomes more of an immediate concern," he told the Star.
According to NASA, 2023DW has a diameter of just under 50 metres. Rein estimates there are around 100,000 or a million" near-Earth asteroids in that size category.
In the days since its discovery, 2023DW has topped the ESA's Risk List - a catalogue of all near-Earth objects with a nonzero chance of impacting the planet. Of the roughly 1,450 objects on the list, 2023DW placed first in terms of impact likelihood. That doesn't necessarily mean it's dangerous, however.
According to Rein, the hazard of near-Earth objects are ranked according to the Torino scale, with zero being harmless and 10 being the worst possible impact. 2023DW clocks in at a one, while every other current object on the Risk List is a zero.
NASA's Planetary Defense Coordination Office announced Tuesday it also had been monitoring 2023DW, adding that it has a very small chance" of hitting Earth. As they continue observing the asteroid, the agency's orbit analysts will be updating predictions with time.
The last time a similarly sized object crashed to Earth was about a century ago in Serbia, Rein said. It caused relatively widespread devastation," flattening trees in 50 square kilometres of uninhabited forest. While 2023DW can be expected to cause a similar impact, Rein said it's far more likely to strike uninhabited areas or the ocean than a major city.
If it were directly to impact the Toronto area, then that would be very bad," Rein said. But, most of the Earth is covered by water and many areas are very sparsely populated, so the probability that... it would cause significant damage would be very low."
Small asteroids pepper Earth all the time, said Ray Carlberg, a professor of astronomy at the University of Toronto. Because of their size, however, they either burn up in the atmosphere or arrive at the Earth with the size of a rock or boulder."
It's the bigger asteroids we need to watch out for, Carlberg continued -for example, the meteorite that wiped out the dinosaurs and caused massive climate change was thought to measure 10 to 15 kilometres in diameter.
When a large, dangerous asteroid does appear, we're not helpless, Carlberg said: NASA is working to develop rockets that will push some of the small, but big enough to be a problem, ones just enough off course so that they miss us."
Kevin Jiang is a Toronto-based staff reporter for the Star's Express Desk. Follow him on Twitter: @crudelykevin