Leave it to a musician. Not satisfied with edgy compositions orbiting the Harmonic Major modes, nor even his surrealistic art where the rocks have eyes, Jon Larsen’s mind went straight to the gutter. And there he found cosmic gold.
As a jazz composer and musician, Larsen travels around Europe playing jazz gigs on his classical guitar. An amateur astronomer, he also digs anything to do with space. Especially when it comes to gutters in his hometown of Oslo. It was there he first collected the muck in the gutters of buildings, made a slurry of it, then passed it over a magnet to catch anything that would stick.
Micrometeorites contain magnetite, a naturally magnetic form of iron oxide, which is also known as lodestone. Larsen struck a mother lode when he finished sluicing his mud. While examining what his magnet captured, he found several micrometeorites.
These little visitors have some unique features that form when they zip through Earth’s atmosphere at about 12km/second, (7.5 miles per second). While falling toward Earth, they become liquid globules, cooling into spheres. The minerals in them take on a striped appearance which makes them resemble tiny marbles with diameters ranging from 300 to about 600 microns.
For years, amateur astronomers claimed that they had found micrometeorites, but such claims were dismissed by professional astronomers. These claims of micrometeorites became an urban myth. Larsen’s efforts would eventually prove that this urban myth was actual fact, vindicating his fellow amateur astronomers’ claims that they had really found micrometeorites where they lived.
With overwhelming success at home, Larsen began collecting gutter samples in cities all over Europe, including Paris. Time and again, he found micrometeorites in the samples he brought back home.
To dispel the claim, once and for all, that micrometeorites were merely an urban myth, Larsen took his collection of about 500 micrometeorites to Imperial College, London and asked Matthew Genge and his colleagues to have a look. They analyzed 48 samples from Larsen’s collection and confirmed that they matched the composition of micrometeorites.
Micrometeorites tend to be high in olivine, a greenish semi-precious stone, and contain iron and nickel alloys. These alloys are rare in Earth-bound rocks because they oxidize rapidly in our atmosphere.
Most gutters are cleaned periodically, meaning that at least some of the micrometeorites collected are less than six years old. Some of these younger micrometeorites have a lot more stripes than older ones, suggesting that they arrived at an extremely high velocity.
Micrometeorite velocity is influenced by the pull of all the planets in our solar system. The change in composition may be due to a slight change in the planets’ orbits.
Since that analysis, Dr. Genge and his colleagues have recognized that the gutters on the world’s buildings may well be a resource for micrometeorites that can be used for general study. While a certain urban myth may prevail in some parts of the web, we now know that it’s true–micrometeorites can be found right where we live.
It’s hard not to smile at the fact that it was a musician’s mind in the gutter that gave us something from the stars.