We are physically much closer to the space particles dated back to the birth of the solar system 6.4 billion years ago than we think! In fact we are so close that we can find them on our roof tops. Well, not exactly, as they are too small to detect. But scientists have discovered cosmic dust raining down from space on roof tops in three major cities. Researchers sifted through 300 kilograms of muck trapped in roof gutters in Paris, Oslo and Berlin. Using magnets to pull out the particles, which contain magnetic minerals, they identified a total of 500 cosmic dust grains.
“We’ve known since the 1940s that cosmic dust falls continuously through our atmosphere, but until now we’ve thought that it could not be detected among the millions of terrestrial dust particles, except in the most dust-free environments such as the Antarctic or deep oceans,” says Matthew Genge at Imperial College London. “The obvious advantage to this new approach is that it is much easier to source cosmic dust particles if they are in our backyards.” City cosmic dust was found to be larger than previously recovered particles, measuring around 0.3 millimetres across instead of the more usual 0.01 millimetres. In addition the dust found in cities contained fewer feather-like crystals than the much more ancient particles from Antarctica.