> As well as living matter, inorganic substances also crash to earth, including seeds, stones and sand. However, these pale in comparison to the mighty ice blocks. January 2000 saw several chunks weighing up to four kilograms each fall on Spain, but they're dwarfed by the 200kg titans that struck Brazil in 1995.
Wat. Does anyone have a reference for the Brazil one? Wikipedia (https://en.wikipedia.org/wiki/Megacryometeor ) mentions nothing. Megacryometeors: Distribution on Earth and Current Research (2006)[0] says:
> In Campinas and Itapira, Brazil, two huge megacryometeors of 50 and 200 kg fell in 1997; the atmosphericisotopic signature of both specimens wasunequivocally confirmed (8). Finally, on 21 July 2004, a huge mass of ice weighingapproximately 400 kg fell very close to a 15-year-old girl in Toledo, Spain.
400kg! Unfortunately, no reference is given for this one and for the one in Brazil they refer to https://cepagri.unicamp.br/gelo/gelo.html, which – like many other of their references – produces a 404 nowadays. And, of course, the page hasn't gotten preserved by the Internet Archive, either. :(
On the contrary, the video gives an excellent analysis of Putin's options, and it's definitely worth watching.
You're right that Putin believes he's infallible, and the Nielsen makes the point that Putin often picks the most stupid option. But it also emphasizes that Europe needs to be ready to act if Putin decides to escalate, and if the US chooses to abandon NATO.
russia's invasion of Ukraine is absolutely solvable. It's just a disgrace that Ukraine is left to do it alone, with huge casualties (civilian as well as military), and inconceivable destruction.
"Our cameras in Northford, Connecticut, and Douglassville, Pennsylvania, as well as a doorbell camera in Wayne, New Jersey, captured the meteor, and from that we measured its trajectory... The path traced back to low in the asteroid belt."
I don't doubt it, but that's an astounding trajectory estimation...
> The dark flight trajectory of a meteoroid is significantly affected by the atmospheric winds, especially by the jet stream. As a result, the meteorite fall position can be shifted by up to several kilometers compared to a scenario with no winds.
That network is mostly interested in where it falls, not where it came from. A few degrees for finding an origin is a huge variation.
Planetary scientists are motivated to physically examine freshly fallen near pristine samples, yes. They are also keenly interested in origins, intra or extra solar system, relationships to known showers et al.
The less public precursors were and still have an interest in both projected targets and sources.
It's trivial to draw a line between some fixed points and extrapolate back to an origin if there's no external forces acting on the asteroid. But there is - planetary gravity, the moon, potentially the sun heating one side of it, atmospheric wind, weather, etc make a big difference. That makes it harder.
That's basics of meteor observation. As long as camera didn't move, you can plot the track against the stars and time is known. Then with two tracks from different locations, orbit is determined.
Also, a typical consumer camera is going to struggle (even with the best analysis!) to have visual accuracy within even a few degrees of true (due to everything from high compression ratios in post processing to shitty optical properties in the actual camera) and that makes a probability cone that is pretty large.
No kidding, that is what I was referring too. Precision for a typical doorbell camera is going to be several minutes of angle at best, which is my point.
And here's the original, in the mid-Dec 1989 issue of Analog Science Fact & Fiction magazine (at the bottom of the page) on the unparalleled Luminist Archives website:
Precedent: A 1944 science fiction story accurately described an atomic bomb – so much so that it prompted a visit from the FBI to the NY office of Astounding Science Fiction. Definitely a point of pride for editor John W Campbell.
(The last line is especially memorable!)