The British and Irish Meteorite Society

Hello everyone,
Again in Russia, Murmansk for footage here http://www.youtube.com/watch?v=iTwfGDs-JWo
and for news http://rt.com/news/meteorite-murmansk-e ... space-588/
hope we will able to see some samples in future.

Regards,

hetlaw wrote:Again in Russia, Murmansk for footage here http://www.youtube.com/watch?v=iTwfGDs-JWo
and for news http://rt.com/news/meteorite-murmansk-e ... space-588/
hope we will able to see some samples in future.

Thanks - a very nice fireball.

I see from the URSA web site that the fireball was also widely observed from across Finland. They've put a map together with preliminary track and potential fall zone for any resulting meteorites. I think they are indicating accuracy of 100km for the location of the potential fall zone. It looks to be a remote and largely wooded area. They've also provided links to the local infrasound network with some good prospects for infrasound detection of the meteoroid's passage through the atmosphere. Infrasound is sound of a frequency below normal human hearing range. The sound is generated by the meteoroid traveling at hypersonic speeds through the atmosphere and associated fragmentation events.

Notes on times. The video suggests a 4 - 5 second visible flight ending around 02:14 MSK in the early hours of the 19th April 2014. MSK is UTC +4 hours, so the fireball occurred at 22:14 UTC on the 18th April 2014. Finland is on EEST (UTC +3 hours), so the reported times of 01:15 EEST on the 19th April 2014, roughly agree. The infrasound data is referenced to UTC.

There look to be probable infrasound detections from Swedish-Finnish Infrasound Network stations at:

Sodankylä (64° 25' 14.2" N 26° 23' 24.7" E) approx 22:27 UTC 18/04/14. Infrasound propagation time 13 minutes onwards.
Kiruna (67° 35' 10.0" N 20° 25' 14.2" E) approx 22:38 UTC 18/4/14. Infrasound propagation time 24 minutes onwards.
Jämtön (65° 51' 46.4" N 26° 23' 24.7" E) approx 22:41 UTC 18/04/14. Infrasound propagation time 27 minutes onwards.

With an end-of-visible-flight close to Zapolyarny, the propagation velocity of the infrasound is roughly:

Sodankylä 1337 km/hr, 371 m/s
Kiruna 1152 km/hr, 320 m/s
Jämtön 1182 km/hr, 328 m/s

Given that the propagation speed will be affected by stratospheric winds, these seem reasonable. In each case the infrasound rumbles on for several minutes.

I see that Денис Смелов has posted a nice video compilation of various CCTV recordings, along with a few stills. The only part I'm not keen on is the graphic of the path of the fireball across the night sky's constellations. I'm guessing that is for an observer in Murmansk, but it would be nice if that was stated, as it'll only be correct for one location.

There are reports here of the first meteorite being recovered from this event. Congratulations to the team that triangulated the path and located the fall.

ITAR-TASS are reporting (in Russian) that an expedition is under-way to the fall site.

Google translation

MURMANSK, September 25. / Correspondent. ITAR-TASS Ilya Vinogradov /. On the Kola Peninsula, researchers from the Sverdlovsk region are going to find one of the largest fragments of meteorites that fell to the territory of Russia. He crashed on the peninsula in April this year. On Thursday, the expedition with the support of the Ural Federal University (UFU) went to the Arctic.

Also reported by Pravda.

The meteoroid's orbit has now be determined by scientists at CSIC (in Spanish). The team provide a press release and some images - one of the Annama meteorite. it looks like Annama is the provisional name. The paper is available here.

David Entwistle wrote:It looks like Annama is the provisional name.

Annama is now the official name.