Emergency services in Devon, southern England, were mobilised this morning (Sunday 8 September 2019) after a number of witnesses reported seeing what appeared to be a plane crash in the Tavistock area slightly before 6.00 am British Summertime. Witnesses reported seeing a glowing object leaving a trail of smoke, which was initially interpreted as a possible light aircraft, but not signs of any debris have been found, and no aircraft reported missing, and it is not thought that the object may have been a meteorite glowing as it burned up in the atmosphere, with a smoke trail produced by material ablating from the surface due to friction with the atmosphere.
Probable meteorite seen in the Tavistock area of Devon, England, slightly before 6.00 am local time on Sunday 8 September 2019. Emma Harris/Devon Live.
Objects of this size probably enter the Earth's atmosphere several times a year, though unless they do so over populated areas they are unlikely to be noticed. They are officially described as fireballs if they produce a light brighter than the planet Venus. The brightness of a meteor is caused by friction with the Earth's atmosphere, which is typically far greater than that caused by simple falling, due to the initial trajectory of the object. Such objects typically eventually explode in an airburst called by the friction, causing them to vanish as an luminous object. However this is not the end of the story as such explosions result in the production of a number of smaller objects, which fall to the ground under the influence of gravity (which does not cause the luminescence associated with friction-induced heating).
These 'dark objects' do not continue along the path of the original bolide, but neither do they fall directly to the ground, but rather follow a course determined by the atmospheric currents (winds) through which the objects pass. Scientists are able to calculate potential trajectories for hypothetical dark objects derived from meteors using data from weather monitoring services.
Witness reports can help astronomers to understand these events. If you witness a fireball-type meteor over the UK you can report it to the UK Meteor Observation Network here.
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