There was always a (very) good chance that the potential city-killing asteroid 2024 YR4 would be found not to be headed exactly our way, and that’s how it has worked out. Christmas 2032 is safe (well, from 2024 YR4, anyway).
As the New York Times reports, the chance of a hit increased for a while as more data came in, reaching a peak of 3.1 percent, the highest “ever recorded by NASA for an object of this size or bigger.”
And then the odds began to fall, until on Monday NASA tweeted the “all clear.” The impact probability had fallen to 0.004 percent, meaning 2024 YR4 “is expected to safely pass by Earth in 2032.” And the odds have since fallen still further. There is still a chance (1.7 percent) that the asteroid may hit the moon, but the moon is used to being knocked around by thugs from the sky, and Moonbase Alpha has yet to be built, so that is no concern.
The good news about this (mini) saga is that it shows how much better our species has become at spotting hazards out there. Not only that; we have a better chance (fingers crossed) of being able to do something about it.
Serious monitoring of objects near Earth only started in the late 20th century, explains Professor Mark Boslough from the University of New Mexico. “Before that we were blissfully oblivious to them,” he says.
We now know that quite large objects – 40m across or more – pass between Earth and the Moon several times a year. That’s the same size of asteroid that exploded over Siberia in 1908 injuring people and damaging buildings over 200 square miles.
The most serious near-miss, and the closest comparison with YR4, was an asteroid called Apophis which was first spotted in 2004 and measured 375 meters across, or around the size of a cruise ship.
Professor Patrick Michel from French National Centre for Scientific Research (CNRS) tracked Apophis and recalls it was considered the most hazardous asteroid ever detected.
It took until 2013 to get enough observations to understand that it was not going to hit Earth.
And at the time, apart from calling on Bruce Willis (not nothing), there was not much we could have done to head it off.
Meanwhile, for those who celebrate, Asteroid Day will, as usual, be on June 30, the anniversary of the Tunguska Event (that Siberian explosion). Marking the day by jeering at pigeons or other dinosaur descendants is frowned upon these days.
For the uh, terminally, online still waiting for SMOD, well . . . despair springs eternal.