ESA: Small meteorite will safely impact atmosphere tonight over northern France
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Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#2ESA's own Twitter stream would be a more direct (and informative, in this case) source:
https://twitter.com/esaoperations/status/1624901825785724929>
Looks as if the predicted entry point will be over Rouen.
That tweet cites Richard Moissl (also on Twitter):
https://twitter.com/Richard_M_F/status/1624890692156751872>
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#3Lot of things going on in space lately
Let's take a moment to remember this beautiful story: https://www.smithsonianmag.com/smart-news/reagan-and-gorbach...
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#4Impactor is ~1m in size, and projected impact time is 04:00 +/- 10 minutes CET (03:00 UCT).
That's about three hours from now as I write this.
My very off-the-cuff estimate is that a 1m impactor might mass anything from a few hundred kilos to a few tonnes, depending on composition (less for ice / chondrites, more for a heavy nickel-iron meteorite).
Looking forward to the skycam views.
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#5ESA's own Twitter stream would be a more direct (and informative, in this case) source: https://twitter.com/esaoperations/status/1624901825785724929 > Looks as if the predicted entry point will be over Rouen. That tweet cites Richard Moissl (also on Twitter): https://twitter.com/Richard_M_F/status/1624890692156751872 >
Ok, changed to that from https://twitter.com/disclosetv/status/1624909455325294593. Thanks!
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#6That's a meteor. Meteorites are different - they're the ones that hit the dirt.
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#7ESA's own Twitter stream would be a more direct (and informative, in this case) source: https://twitter.com/esaoperations/status/1624901825785724929 > Looks as if the predicted entry point will be over Rouen. That tweet cites Richard Moissl (also on Twitter): https://twitter.com/Richard_M_F/status/1624890692156751872 >
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Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#8Impactor is ~1m in size, and projected impact time is 04:00 +/- 10 minutes CET (03:00 UCT). That's about three hours from now as I write this. My very off-the-cuff estimate is that a 1m impactor might mass anything from a few hundred kilos to a few tonnes, depending on composition (less for ice / chondrites, more for a heavy nickel-iron meteorite). Looking forward to the skycam views.
Stupid question: if the impact time is +/- 10 minutes, doesn't that translate into a lot of uncertainty for where it will hit? How do they know it's going to be Rouen?
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#9Impactor is ~1m in size, and projected impact time is 04:00 +/- 10 minutes CET (03:00 UCT). That's about three hours from now as I write this. My very off-the-cuff estimate is that a 1m impactor might mass anything from a few hundred kilos to a few tonnes, depending on composition (less for ice / chondrites, more for a heavy nickel-iron meteorite). Looking forward to the skycam views.
Stupid question: if the impact time is +/- 10 minutes, doesn't that translate into a lot of uncertainty for where it will hit? How do they know it's going to be Rouen?
My (lay, nonexpert) understanding is:
- The centroid of probability is near Rouen.
- Earlier/later impact probability would be along a path along the movement/orbit of the impactor. I'm going to guess that that's largely east-west track, though with a possible orbital inclination.
- The probability distribution across that range is likely far higher near the centre than at the extremes.
- Relative motion of Earth's rotation (~1,600 km/hr at the equator, less than that at the latitude of Rouen) is a much smaller component than the likely relative velocity of the meteorite (~20 km/s).
- 20 km/s +/- 10 minutes ... gives 12,000 km as a possible range around the impact site.
There's also the question of accurately noting the original position of the impactor.
That said: good question and I'd love to hear from someone who knows what they're talking about.
Thought also comes to mind of Aristotle's future contingents, "there will be a sea battle tomorrow" ...
Re: ESA: Small meteorite will safely impact atmosphere tonight over northern France
#10ESA's own Twitter stream would be a more direct (and informative, in this case) source: https://twitter.com/esaoperations/status/1624901825785724929 > Looks as if the predicted entry point will be over Rouen. That tweet cites Richard Moissl (also on Twitter): https://twitter.com/Richard_M_F/status/1624890692156751872 >
Ok, changed to that from https://twitter.com/disclosetv/status/1624909455325294593 . Thanks!
Appreciated.
(For those reading this: I'd of course emailed hn@ycombinator.com, largely with the text in my comment. It's an effective way to get attention / make changes to posts.)