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Icy-Conclusion-3500 t1_jdobtce wrote

Reply to comment by Rhaedas in [NASA on Twitter] Newly-discovered asteroid 2023 DZ2 will pass Earth more than 100,000 miles (161,000 km) away–about half the distance to the Moon–making its close approach at 3:51 p.m. EDT (12:51 p.m. PDT) by ICumCoffee

Yes, but it’s said in like a “don’t worry!” way, but clearly we haven’t found them all.

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Rhaedas t1_jdochbw wrote

We'll never find them all if you include ones that are perturbed from the outer parts of the system to fall inward. And we'll definitely not find ones in time without a better search and detection program. Relying on amateur astronomers and rare free time at the major telescopes, both only done at night, it pretty limited and why so many near passes are discovered after they do pass and not before.

I do wonder if there's any validity in Asimov's prologue for Rama, where Spaceguard uses a nuclear blast (neutron?) to generate a radar image of the system to map just about everything. Of course Rama was conveniently not in this scan.

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danielravennest t1_jdrd3al wrote

> And we'll definitely not find ones in time without a better search and detection program.

There are already dedicated telescopes like Atlas. A much bigger survey telescope is under construction, the Rubin Observatory. It is expected to increase discoveries by a factor of 10.

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Rhaedas t1_jdrlzvf wrote

Both impressive and the results of Atlas since operation shows it's doing a great job. A space-based telescope system would be able to do so much more, especially since it wouldn't have the limitations of only scanning the night sky that a ground one does. A key point - any impactor that is in a orbit similar to Earth's is that the last years of its path will be from the Sun side of the planet. The sooner we see anything and can calculate mass and vectors the sooner we can do any action that we might be able to do. Another key point - to be able to do anything like deflection we have to get to the object first long before its arrival, so knowing years in advance is crucial.

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