20 July 2010

White-hot meteorite story is undoubtedly bogus

The Bosnian fellow in the photo above claims his house has been hit on six different occasions by meteorites:
The white-hot rocks have hammered Radivoje Lajic's house repeatedly since 2007, forcing him to reinforce the roof of his Gornji Lajici home with a steel girder.
Experts at Belgrade University have confirmed that all the rocks he has produced are meteorites, but Lajic believes their trajectory is no accident, claiming: "I am obviously being targeted by aliens."

Lajic has had so many visitors to his house that he plans to erect a small museum in his back garden.
Apart from the obvious mathematical improbability, his claim that the meteorites are "white-hot" reflects a common misperception:
When a meteor lands on Earth, it is not usually hot. Small meteorites are not hot when they fall to Earth — in fact, many are found with frost on them. A meteorite has been in the near–absolute zero temperature of space, so the interior of it is very cold. A meteor's great speed is enough to melt its outside layer, but any molten material will be quickly blown off (ablated), and the interior of the meteor does not have time to heat up because rocks are poor conductors of heat. Also, atmospheric drag can slow small meteors to terminal velocity by the time they hit the ground, giving them time to cool down.
Unfortunately, there really aren't very many meteors that are picked up directly after they've fallen, so it's hard to do good statistics on which ones are hot or cold. So far it seems that some of each have been found. For example, this FAQ lists reports of meteorites (compiled by Don Blakeslee of Wichita State University) that have been touched soon after they fell, and some people reported that the rock was hot, some that it was warm, and some that there was frost on the outside! These reports are all of a qualitative nature, usually based on the testimony of a small number of people.
Via Nothing to do with Arbroath.

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...