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Asteroid ZTm0038 with a >3% impact probability

newton.spacedys.com

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Re: Asteroid ZTm0038 with a >3% impact probability

#141

Post by version_five »

jacquesm wrote: post #134
dougmwne wrote: post #113

Earlier quoted context omitted.

That would sound like a kinetic bombardment weapon and that we were about to get rodded. My level of concern would be sky high!

Depending on how it is aimed... straight in that would be messy.

That would be an interesting analysis to see, my guess is it wouldn't be that different than if it was a sphere of equivalent mass, and vs a 400m sphere would be 400/(4*pi*200^3/3) = .0012% the volume (and so kinetic energy), and it would not penetrate in a way that does specifically worse damage. Just guessing though.

Edit: I confused radius and diameter in my calculation and revised it. I may have made other mistakes

Re: Asteroid ZTm0038 with a >3% impact probability

#142

Post by jacquesm »

JumpinJack_Cash wrote: post #98

The public is unanimously in favor of funding asteroid protection mechanisms and research. It's even higher support than the military. Naturally what do we do with that money and goodwill instead? Yes! Let's build a massive space telescope which takes pictures that are only marginally better than the other multi-billion dollar space telescope! Protect the Earth? Fuck that, don't ya know kid? She's toast anyway becaus…

There have been many studies about what could be done to deal with asteroids that are on track to impact earth and the simple answer is 'nothing'. Frustrating, but unless you can think of something that none of the very clever people on those committees could think of it's going to stay that way.

Re: Asteroid ZTm0038 with a >3% impact probability

#143

Post by lucb1e »

jacquesm wrote: post #137
moonchrome wrote: post #115

That's what I get for reading HN before going to sleep...

If you wake up: no problem. If you don't wake up: no problem.

> If you wake up: no problem

Depends on what you wake up from: sirens and broken windows everywhere but not a direct hit, for instance, I wouldn't call 'no problem' :(

Re: Asteroid ZTm0038 with a >3% impact probability

#144

Post by EGreg »

radicaldreamer wrote: post #120
ortusdux wrote: post #89

Earlier quoted context omitted.

This paper is an interesting read: https://www.sciencedirect.com/science/article/pii/S009457651... Not my area of expertise, but it sounds like a deep ocean impact would not be completely catastrophic. With only ∼1% of the asteroid kinetic energy being converted into tsunami waves and with the stronger decay with distance implies that moderate size asteroids (100–500 m in diameter) striking the deep ocean basins off…

If it hit land anywhere other than Siberia or the Sahara, it would be pretty bad!

How bad is the question

Re: Asteroid ZTm0038 with a >3% impact probability

#146

Post by jacquesm »

lucb1e wrote: post #143
jacquesm wrote: post #137

Earlier quoted context omitted.

If you wake up: no problem. If you don't wake up: no problem.

> If you wake up: no problem Depends on what you wake up from: sirens and broken windows everywhere but not a direct hit, for instance, I wouldn't call 'no problem' :(

Fair enough, that would definitely be a possibility. The dashcam and other videos from Siberia are still very fresh in my mind. That was a very close call. Slightly different angle in a more populous part of the world...

Re: Asteroid ZTm0038 with a >3% impact probability

#148

Post by noduerme »

Leary wrote: post #132
killthebuddha wrote: post #100

I'm having a weirdly difficult time finding some basic ELI5 answers. - What is the probability that this asteroid will hit us? - What is the time interval where that probability applies? - Do we have a probability distribution for where it might hit? I don't know anything about anything, but I assume we know what *general direction* it's coming from? - Do we have a probability distribution for the potential blast rad…

Found this tweet with an impact probability map that is around northern US/Asia/Europe : https://twitter.com/JoelSercel/status/1691549821629526219 "If it is real this IS the worst asteroid threat ever discovered and the impact location and times are ugly (will post pics shortly). Note that the impact is in the next couple days! However, an Italian colleague of one of our astronomers suspects there is an error in the…

If I'm looking at the time chart correctly, that basically corresponds to "daylight hours", when you're facing the sun, tomorrow within the northern hemisphere...

Re: Asteroid ZTm0038 with a >3% impact probability

#150

Post by ortusdux »

lucb1e wrote: post #99
Keyframe wrote: post #65

Earlier quoted context omitted.

Where did you get its albedo (reflectivity)?

That's in the submission, there's a column called H in the first table that says 19.90

The chart is H vs. Albedo, and is awkwardly formatted. H is the brightness observed on earth. Albedo is the inherent reflectivity of the object. What the chart is saying is that if we observe an object that is 19.5 H bright, it could either be highly reflective (0.30 albedo) and 310m across, very dim (0.05 albedo) and 760m across, or somewhere in between.

As I understand it, we can only calculate the albedo if we know the size and apparent brightness.

I'll note that the linked NEOscan page has an H of 19.9, while JPL's CNEOS has an H of 19.2.

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