Fireball over Finland, 29 May 2013

[Niall]

http://www.ursa.fi/index.php?id=5120

If a Finn could translate this, we can get it up on SOTT.

 

[Seppo Ilmarinen]

I can give it a shot!

 

[Seppo Ilmarinen]

The flight route of the bright fireball that fled over Southern Finland at wednesday 8th of may has been modelled out. Esko Lyytinen, mathematician of URSA astronomical association and member of URSA Finnish Fireball Working Group estimated, that about 5kg fraction of the fireball ended on the surface of earth, in souther part of Huittinen. There was over 300 sightings of the fireball reported in the URSA database.

The exact flight route estimation was based on the meteor camera pictures of URSA Finnish Fireball Working Group. Photographers of the fireball route was Johan Linden in Turku and Aki Taavitsainen in Mikkeli.

The cause of the fireball light phenomena was meteoroid, that passed through the atmosphere. Based on the simulation, the mass of the meteoroid was about 50 kilograms, and it's diameter was about 30 centimeters. It arrived into the atmosphere in 43 degree angle.

The speed of the object was about 23 kilometers per second, when it arrived the atmosphere. It ignited into glowing fireball near Mynämäki at height of 60 kilometers from where it travelled into north-east. After crossing lake Pyhäjärvi the fireball flamed out at north east of Säkylä, at altitude of about 23 kilometers.

It's usually very challenging to find meteors at the terrain of Finland. There hasn't been found any of the pieces of the fireball yet. The impact zone is about 10 kilometers to south from the center of Huittinen.

Even thought the fireball was impressive, it was still about 200 000 times smaller that the one that was seen over Russia, Tseljabinski at february 15th. The object that impacted Tseljabinski was originally 17-meter diameter asteroid, and it's mass was about 10 million kilograms.

HUNDRED TONNES OF SHOOTING STAR MATERIAL

Atmosphere of earth is impacted daily by hundred tonnes of small objects from space, which nearly all will get destroyed, when they pass through the atmosphere. Small fragments of that material will heat up during their fall and start to glow. As they fall, they will cause bright flashes in the sky, that are called shooting stars.

If the object that ends in the atmosphere is so large, that it's magnitude is brighter that any star or planet, it is called fireball. Shooting star is called fireball if it's magnitude is brighter that the planet Venus. Smaller fireballs usually burn out in the atmosphere and there are several reports of them in Finland, throughout the year. Most significant fireballs are considered for example those objects, which end up in the surface of earth as a half kilogram (at least) meteorite.

The phenomenon of 8th of may was a significant fireball, that was part of the 5 kilogram meteor and the supersonic explosion it caused.

Here's the translation, all the information should be there but I'm not 100% sure of the grammar.

 

[Niall]

Great, thanks Seppo!

http://www.sott.net/article/262255-Trajectory-modelled-for-fireball-that-exploded-over-Southern-Finland-with-supersonic-boom-8-May-2013

 

[Breton]

Thanks Seppo for doing the translating!

I noticed that the URSA link no longer works. I wonder what is up with that? I cannot seem to find it on their site anymore, it is a bit confusing to find old articles.

http://www.ursa.fi/index.php?id=5120

 

[Tomiro]

Thanks Seppo for doing the translating!

I noticed that the URSA link no longer works. I wonder what is up with that? I cannot seem to find it on their site anymore, it is a bit confusing to find old articles.

http://www.ursa.fi/index.php?id=5120

This seems to be the new link to the article:
http://www.ursa.fi/index.php?id=5097

 

[Breton]

Thanks Tomiro!

It seems I just had trouble figuring out where they were archiving the sightings.

Etusivu » Palvelut » Tiedotusvälineille » Tiedotteet

 

[Tomiro]

Yeah, their site is somewhat hard to navigate. I browsed around a bit and stumbled upon this statement:

http://www.ursa.fi/palvelut/tiedotusvalineille/tiedotteet/2013/pieni-asteroidi-ohittaa-maan-lahietaisyydelta-152.html

Asteroids and comets moving around earth are continuously monitored by different scientific projects. Researchers estimate that 99% of the hazardous large-sized objects are already known, and their movements are continuously monitored. Smaller objects are constantly being found. 2012 DA14 is so small that it is not considered a major threat to the planet, but it's also continuously being monitored.

So they are claiming that everything is under control. Larger (>1km?) objects are monitored and smaller objects basically pose no "major" threat to us. This was before the Russian explosion, that again was caused by a body half the size of the mentioned asteroid (~20 meters), and clearly capable of causing serious damage. Even NASA has stated that there is not much to be done about "city killers", but those are obviously just labelled as "minor" threats.

But yeah, nothing to see here.