The likelihood that a newly discovered asteroid with the potential to wipe out a city will hit Earth on Valentine’s Day 2046 has dropped, the European Space Agency said on Tuesday.
The asteroid, named 2023 DW and estimated to be about the size of a 50-meter Olympic swimming pool, was first spotted by a small Chilean observatory on February 26.
It quickly rocketed to the top of NASA’s and ESA’s lists of asteroids posing a threat to Earth, prompting a slew of alarming headlines, with some aficionados warning to cancel their February 14, 2046 Valentine’s plans.
Late last month, the asteroid had a 1 in 847 chance of hitting Earth – but the odds rose to 1 in 432 on Sunday, according to ESA’s risk list.
However, Richard Moissl, the head of ESA’s Planetary Defense Office, told AFP on Tuesday that the probability had dropped to one in 1,584 overnight.
“It will now decrease with each observation until it reaches zero at the latest in a few days,” he said.
“No one needs to worry about this guy.”
NASA on Tuesday lowered its own impact probability to one in 770, meaning there was a 99.87 percent chance the asteroid would miss Earth.
“We tend to be a bit more conservative, but there definitely seems to be a downtrend in probability now,” NASA Planetary Defense Officer Lindley Johnson told AFP.
He said it’s normal for the impact probability of newly discovered asteroids to rise briefly before falling rapidly.
That’s because new observations narrow the “region of uncertainty” that the asteroid will travel to at its closest point, he said.
While Earth is still within this region of uncertainty, the odds increase temporarily — until further observations rule out Earth and the probability drops to zero, as expected in 2023 DW.
What if it hits the ground?
But what would happen in the increasingly unlikely event that the asteroid hit Earth?
Davide Farnocchia, a scientist at NASA’s Center for Near-Earth Object Studies, said a good comparison is the Tunguska event, in which a similarly sized asteroid is believed to have exploded in the atmosphere over a sparsely populated area in Siberia in 1908.
“The resulting explosion flattened trees over an area of about 2,000 square kilometers,” Farnocchia said. London covers an area of around 1,600 square kilometers.
Moissl said a 2023 DW-sized asteroid would cause “regionalized destruction” and not have a major impact on the rest of the world.
The asteroid orbiting the Sun made its last closest approach on February 18 – a week before it was discovered – about nine million kilometers from Earth.
If it were to hit Earth in 2046, it is estimated that it would be traveling at a speed of around 15 kilometers per second.
It has about a 70 percent chance of landing in the Pacific Ocean, but the potential attack zone would also include the United States, Australia or Southeast Asia, Moissl said.
Even if the asteroid is heading towards us, the experts emphasized that the world is no longer defenseless against such a threat.
Last year, NASA’s DART spacecraft intentionally crashed into the pyramid-sized asteroid Dimorphos, throwing it significantly off course in the first such test of our planetary defenses.
Farnocchia said the “DART mission gives us confidence that such a mission would be successful,” if necessary, around 2023 to DW.
With 23 years of preparation, Moissl said there was “enough time” to plan such a mission.
ESA’s Hera mission, due to launch next year to study the damage DART had on Dimorphos, could even be repurposed for reconnaissance if needed, he added.
Such plans would not be considered until the probability of an impact exceeded one in 100 if they attracted the attention of UN-backed bodies like the International Asteroid Warning Network and the Space Mission Planning Advisory Group (SMPAG), he said Moissl.
SMPAG’s goal is to “get everyone on the same page and avoid what happened in the movie Don’t Look Up” where “stupid stuff” happened because the nations didn’t align , added Moissl.
However, such defenses are unlikely to be required for 2023 DW.
“Everyone should relax, ignore the sensational headlines and stories, and watch how this situation unfolds,” NASA’s Johnson said, adding that any threat would likely “dissipate” soon.
“Nevertheless, the planetary defense community will continue to look up!”