2012 UK meteoroid
The bolide of 21 September 2012 has been an unexpected, spectacular celestial event, which in the late evening hours, many people in Central and Northern Europe terrified and fascinated. It is still unclear whether it could not have possibly traded to diminishing auxiliaries space debris. In addition, a link to a similar phenomenon in North America was examined a few hours later, by which it was suspected that it could have been the same object.
Observations
Against 23:34 clock (all data CEST) registered a rapidly migrating westward fireball from numerous eyewitnesses and stationary cameras in the southern parts of Finland. She moved there, according to the Finnish mathematician Esko Lyytinen at an initial height of about 80 kilometers. She was spotted between Helsinki in the south, Oulu in the north, Turku in the west and in the east Kerimäki.
About 15 minutes later, the bolide also appeared in the night sky over northern Germany and was, for example, in Bremen, Osnabrück and Lingen (Ems ) sighted. He presented himself while yellow- greenish bright with a long white- orange tail. It is assumed that he crossed the coastline at about the level of the Elbe estuary and to the northwest further moved across the North Sea. Once in the Netherlands - about from Almelo, Rhenen and Uden - also relevant observations were reported, crossed the fireball in the sequence north of England, the Isle of Man and against 23:55 clock Ireland, where finally the most sightings were made by far. At this time the object was, however, already broken into numerous fragments that initially flew in combination and can be removed further and further from each other. The bolide could be perceived anywhere in the British Isles, its visibility reached to the Shetlands.
Depending on location, the duration of the visibility of the cars varied sometimes considerably. Tim O'Brien of Jodrell Bank radio observatory they estimated at about 40 seconds.
Origin, fate, and related
"I have never seen anything like it before in my life. "
Especially in the United Kingdom and Ireland, where the event countless calls from concerned citizens with authorities and emergency services had the effect, and a wide media reception learned several experts came forward within a few hours with their hypotheses as to the origin of the object to word.
The astronomer and presenter of BBC Two broadcast Stargazing Live, Mark Thompson, for example, expressed, it would most probably space debris - approximately a crashing old artificial satellite - traded. As an argument he led among other things to the color, which is not characteristic for a meteor or meteoroid, which otherwise usually possess a whitish tail track. The same opinion also represents Tim O'Brian, the BBC said that the fireball would have been traveling at a speed of about 18,000 kilometers per hour. Their relatively long visibility interpret his opinion indicates diminishing auxiliaries space junk. David Moore, chairman of the popular astronomy clubs Astronomy Ireland, O'Brian gave is correct in that he also remarked that the phenomenon for ordinary atmospheric declines had been too slow. But he also pointed out that it was drawn for the maintenance of space junk hypothesis in the wrong direction. This is true, however, only if it has not been a rare satellites in retrograde orbits.
Esko Lyytinen is sure the fragments of the bolide had not penetrated at least over Europe the atmosphere up to a possible impact on the earth's surface, but would rather drawn westwards. He thinks it possible that it was at a ball of fire which appeared 155 minutes later across the United States and Canada, and acted the same object. Accordingly, the bolide over Europe had occurred with relatively slow 13 km / sec in the atmosphere - which corresponds to only slightly more than the escape velocity. The braking and relief annealing by the friction at the fall reduced the speed to 9.2 km / sec; Lyytinen calculated that the object reached a height of 53 kilometers at its perigee. The low speed in combination with the angle of entry resulting in a curvature of the trajectory by the gravity. This allowed for an exceptionally long atmospheric passage. According to Lyytinen the bolide left west of Ireland once again the atmosphere, but remained in orbit. Maybe he subsequently completed a full orbit before was the re-entry over North America. There has focused the majority of sightings in New England and the Canadian province of Quebec, but also from Florida and the West Coast were appropriate messages. Supported this hypothesis among others, the air and space engineers and meteor expert Robert Matson, regardless of the Finns also calculated that the bolide regained height at the end of the observed track in Europe. On October 7, the same year, Matson announced that they had agreed that but there is no link between the two celestial events.