Evrim Yazgin
Cosmos science journalist
Asteroid 2024 YR4 has made international headlines since its discovery in December last year because of its (very low) chance of hitting Earth sometime in the next decade.
Initially, NASA scientists predicted that the 40–90m asteroid had a 1.3% chance of hitting Earth in 2032. That probability increased to about 3% earlier this month thanks to updated observations.
Now the European Southern Observatory’s Very Large Telescope (ESO’s VLT) and other facilities around the world have new data which all but erases the risk.
More observations were prompted by the initial threat posed by the so-called “city killer” asteroid. The latest analysis by the European Space Agency places the risk that the asteroid will strike Earth in 2023 at just 0.001%.
It’s not easy trying to predict the years-long trajectory of a building-sized object millions of kilometres away.
“Because of the uncertainties, the orbit of the asteroid is like the beam of a flashlight: getting broader and broader and fuzzier in the distance,” explains ESO astronomer Olivier Hainut. “As we observe more, the beam becomes sharper and narrower.”
“The narrower beam is now moving away from Earth.”
If nothing else, 2024 YR4 has highlighted the importance of remaining vigilant and preparing mitigation measures to prevent possible future asteroid collisions from causing massive destruction.
