TL;DR: NASA and ESA have identified asteroid 2024 YR4 as a significant threat, ranking it at level 3 on the Torino Impact Hazard Scale.
NASA and European Space Agency (ESA) officials have issued an update on an asteroid that is officially considered the most significant threat to Earth.
2024 YR4
A NASA-operated telescope located in Chile detected a suspicious object on Christmas Day, and after human researchers conducted manual follow-up observations, the object was found to be an asteroid now referred to as 2024 YR4. Astronomers discovered the asteroid's orbit around the Sun is elongated, and it's currently traveling directly away from Earth, almost in a straight line.
Because of its position relative to Earth and its straight-line trajectory, researchers struggled to measure its characteristics and project its orbit into the future. Preliminary measurements stated that 2024 YR4 is anywhere between 130 and 300 feet in diameter and is traveling at a speed of 38,700 mph.
Why is this a big deal? Based on the information already gathered, 2024 YR4 has already made it to the top of the Torino Impact Hazard Scale, which is a scale that measures from 1 - 10 and categorizes potential Earth impact events. At the moment, 2024 YR4 is ranked at level 3, which has put it at the top of the list of most dangerous near-Earth objects (NEO) astronomers have on the books.
Now, space agencies have posted updates on 2024 YR4, with NASA writing that additional observations and analysis of the asteroid have been conducted, and the probability has increased from the previously reported 1.3% to 2.3%. If 2024 YR4 does hit Earth, it will most likely be on December 22, 2032. Moreover, space officials estimate that if it does collide with Earth, it will generate an astonishing 7.6 megatonnes of energy, which is an explosion approximately 500 times larger than the nuclear bomb dropped on Hiroshima in World War 2.
Researchers are going to continue with observations of the asteroid until April this year, as 2024 YR4 will then pass behind the Sun and out of view from Earth. However, in March next year, the world's most powerful telescope, the James Webb Space Telescope (JWST), is scheduled to point its instruments at the potential impact. Webb's infrared instruments will paint a much clearer picture of 2024 YR4 and provide astronomers with the information they need to accurately measure the asteroid's size, composition, and other characteristics.
The first round of Webb's observations is scheduled to take place in early March, with the second round scheduled for May.
It should be noted that current estimates by researchers state there's a 98% chance 2024 YR4 will miss Earth.