101–110 of 311 posts
So, uh, NASA was expecting this. They were going to have a livestream chat about this? Er, looks like they got the prediction slightly off. http://www.nasa.gov/mission_pages/asteroids/news/asteroid201... *For the person who downvoted me, there is supposed to be a near earth flyby tomorrow of an asteroid called 2012 DA14 which will be livestreamed with commentary by NASA here: http://www.ustream.tv/nasajpl2 . A reason…
Here's a collection of insane videos of the event, some with the enormous sonic boom: http://www.youtube.com/watch?v=XIAm5hq8WWc http://www.youtube.com/watch?v=b0cRHsApzt8 http://www.youtube.com/watch?v=Np_mpGYSBSA Can anyone translate what they are saying in the first one? You can get a good idea of the new videos being posted using YouTube's "last hour" filter: http://www.youtube.com/results?search_query=%D0%BC%D0%…
Here's a great dashcam video that captures the meteor arcing across its field of vision and lighting up the scene more brightly than the sun like a nuclear blast (first submitted to HN by dennisgorelik). I almost thought it was a hoax, and even tried to examine the video for signs that it was CGI. http://www.youtube.com/watch?v=tJOJ6B2XOyA The guy doesn't even say anything for a long while, just starts speeding up. e…
I can't get over how long it takes for the sonic boom to hit. This video has the meteorite trail on camera for 27 seconds before you hear the boom: http://www.youtube.com/watch?v=Np_mpGYSBSA How fast does something have to be travelling to build up a delay like that?
While it's moving at great speed, it's really about distance that determines the gap with sonic booms. Speed of sound is ~340m/s at sea level, so using that value with a gap of 27 seconds we can assume the boom originated ~9.1km away from the camera(thus it took 27 seconds for the sound to reach the camera). The distance is probably wrong given the speed of sound is different depending on the altitude. The speed had…
I was thinking of terms of the pressure front lagging further behind the meteorite in proportion to the length of time that the meteorite is traveling at a speed greater than the speed of sound.
Thanks for the explanation.
8:10 GMT: Oleg Malkov, an aerospace scientist at
Moscow State University, told Komsomolskaya Pravda
newspaper that the meteorite went undetected by
space scanners, likely because it was coming from
the direction of the Sun.
"We can only register stones coming from the
direction of the night sky," he explained. Malkov
confirmed that the meteor shower in the Urals
was not connected to the 2012DA14 asteroid that
will approach Earth in a few hours.
7:46 GMT: Ekaterinburg’s observatory has officially
deemed the incident a fireball meteor shower. No
evacuations were called for, and radiation levels
were determined to be normal.
Source:
http://rt.com/news/russia-meteor-meteorite-asteroid
-chelyabinsk-291/Earlier quoted context omitted.
Here's a great dashcam video that captures the meteor arcing across its field of vision and lighting up the scene more brightly than the sun like a nuclear blast (first submitted to HN by dennisgorelik). I almost thought it was a hoax, and even tried to examine the video for signs that it was CGI. http://www.youtube.com/watch?v=tJOJ6B2XOyA The guy doesn't even say anything for a long while, just starts speeding up. e…
That is surreal. My jaw dropped as it came into perspective. Looks like it came straight out of Hollywood.
http://www.slate.com/blogs/bad_astronomy/2013/02/15/breaking...
The contrails, and the videos, show that the meteorite (or pair of meteorites) grew very hot, but survived at least in part and probably fell to the surface. I would love to see the recovery effort.
Notice the long delay between recording the image of the contrail and the sonic boom. This reveals how high the meteorite's path was at the location of the recording.
Do meteorites really do this? I've never heard of another like this event before, and I always hear reports about meteors 'almost' hitting earth well in advance of the possible collision date. I didn't think the sky could simply open up and rain down hellfire without anybody spotting it beforehand.
http://goo.gl/V7491
http://goo.gl/4Rqk0
http://goo.gl/WHR65
http://goo.gl/PUH6q
http://goo.gl/qlXE3
http://goo.gl/LRD52>According to unconfirmed reports, the meteorite was intercepted by an air defense unit Anyone else catch this? Is this just a bad translation and they mean to say that an air defense unit tracked the meteorite on radar? I wouldn't think any air defense system would be capable of actually intercepting a meteorite, but perhaps I'm wrong. Still doesn't seem like anything intercepted it from the videos.
I'd be amused to hear Mathias Rust's assessment of that report. http://en.wikipedia.org/wiki/Mathias_Rust