Asteroid 2024 YR4 has been downgraded to Level 0 on the Torino impact scale after further observations showed it has only a very small chance of hitting Earth.
Asteroid 2024 YR4 was first discovered on December 27, 2024. Astronomers have been keeping a close eye on it ever since, as initial observations showed around a 1 percent chance that it could collide with Earth on December 22, 2032. Follow-up observations of the asteroid briefly showed a higher chance of the asteroid making an impact. At 3.1 percent, it briefly became considered the most dangerous space object since tracking began.
“It is perfectly natural that the impact chances for asteroid 2024 YR4 will bounce around a bit,” Richard P. Binzel, inventor of the Torino Impact Hazard Scale for asteroids, explained to IFLScience as the chance of impact hit 1 in 32. “While certainty for 2024 YR4 missing the Earth is the outcome we expect, it’s not up to us. It’s for nature to decide. In fact, nature already has settled the question. We just don’t know that answer yet. That’s why the tracking efforts continue.”
In bad news for anyone hoping to Bruce Willis an asteroid (or conduct a DART-style mission to deflect it), new observations now place the chance of impact with Earth at a reassuring 0.0039 percent, or 1 in 26,000. In other words, there is a 99.9961 percent chance that the asteroid will miss us on its approach in 2032.
The new observations place 2024 YR4 well within Level Zero on the Torino impact scale.
“The likelihood of a collision is zero, or is so low as to be effectively zero,” NASA explains of the level, adding that it, “also applies to small objects such as meteors and bodies that burn up in the atmosphere as well as infrequent meteorite falls that rarely cause damage.”
Prior to this, asteroid 2024 YR4 had been at Level 3. As explained by the level’s description, the expectation was always that the risk of impact would trend downward.
“A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of localized destruction,” the description reads. “Most likely, new telescopic observations will lead to re-assignment to Level 0. Attention by public and by public officials is merited if the encounter is less than a decade away.”
Though the risk of impact is now low, the 2032 approach is still a close one. Currently, on that visit, it is expected to come within around 0.00179 astronomical units (AU) of Earth, with one AU being the average distance between the Earth and the Sun.
The Moon will get a closer look, as it zips by at a distance of around 0.00008 AU.
