YR4 Asteroid: The Hits and Near-Misses You Never Hear About
upstart writes:
YR4 asteroid: The hits and near-misses you never hear about:
A large asteroid known as 2024 YR4 has grabbed headlines this week as scientists first raised its chances of hitting earth, then lowered them.
The latest estimate says the object has a 0.28% chance of hitting Earth in 2032, significantly lower than the 3.1% chance earlier in the week.
Scientists say it is now more likely to smash into the Moon, with Nasa estimating the probability of that happening at 1%.
But in the time since 2024 YR4 was first spotted through a telescope in the desert in Chile two months ago, tens of other objects have passed closer to Earth than the Moon, which in astronomical terms sounds like a near miss.
It is likely that others, albeit much smaller, have hit us or burned up in the atmosphere but gone unnoticed.
This is the story of the asteroids that you never hear about - the fly-bys, the near-misses and the direct hits.
The vast majority are harmless. But some carry the most valuable clues for unlocking mysteries in our universe, information we are desperate to get our hands on.
[...] 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.
[...] Now that the chances are higher that YR4 will hit the Moon, some scientists are getting excited about that.
An impact could give real-world answers to questions they have only been able to simulate using computers.
"To have even one data point of a real example would be incredibly powerful," says Prof Gareth Collins from Imperial College London.
"How much material comes out when the asteroid hits? How fast does it go? How far does that travel?" he asks.
It would help them test the scenarios they have modelled about asteroid impacts on Earth, helping create better predictions.
YR4 has reminded us that we live on a planet vulnerable to collisions with something the solar system is full of - rocks.
Scientists warn against complacency, saying it is a matter of when, not if, a large asteroid will threaten human life on Earth, although most expect that to be in the coming centuries rather than decades.
In the meantime, our ability to monitor space keeps improving. Later this year the largest digital camera ever built will begin working at the Vera Rubin Observatory in Chile, able to capture the night sky in incredible detail.
And the closer and longer we look, the more asteroids spinning close to Earth we are likely to spot.
Read more of this story at SoylentNews.