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danielravennest t1_jajhve6 wrote

Reply to comment by the_fungible_man in NASA: Several large asteroids projected to zoom past Earth this week by 1080krld

Risk is based on size and impact probability. The asteroid with the highest risk ranking is 101955 Bennu. But it won't have a chance of impact until 2178.

We already sent a probe to it, and grabbed a sample that is due to land on Sept. 24th.

Everything else that shows up in news stories is either lower chance of impact, too small to do much damage, or so far in the future we're not worried yet.

On April 13th, 2029 the asteroid 99942 Apophis will pass only 31,600 km from the Earth's surface, but we know its orbit with 3 km uncertainty, so it will definitely miss us. The same probe that visited Bennu is being retasked to meet up with Apophis. There will probably be a lot of hype about that asteroid before it arrives.

Any other news story about asteroids approaching Earth are clickbait. If one that was a real hazard is discovered, it would be the top story in all the news media.

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TheKingPotat t1_jamq2h6 wrote

The Aphophis flyby sounds like it will have immense scientific value for orbital and ground based telescopes to get a better look at it as well

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danielravennest t1_jamzcnl wrote

It will be moving too fast for Hubble or Webb to track during the flyby (and Webb can't point towards Earth and the Sun). But they can try when it is farther away and appears to move more slowly. Some weather and military satellites in GEO may be able to spot it, and every telescope and radar on the ground will give it a try. Osiris-REX will be chasing it, and will try to boop Apophis like it did for the sample collection on Bennu, but the sample head is gone now.

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TheKingPotat t1_jamzvkh wrote

Would optical observetories on the surface have any shot realistically? Or would it still move too fast

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danielravennest t1_jan1f25 wrote

It will just appear as a streak or series of dots, like satellites do already. It will be visible to the unaided eye if you are in the right place to see it at its closest.

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