After decades of failures and misunderstandings, scientists have solved a cosmic riddle—what happens to the tons of dust particles that hit Earth every day but seldom if ever get discovered in the places that humans know best, like buildings and parking lots, sidewalks and park benches.
Look harder. The tiny flecks are everywhere.
An international team found that rooftops and other cityscapes readily collect the extraterrestrial dust in ways that can ease its identification, contrary to science authorities who dismissed the idea. Remarkably, the leader of an international discovery is a gifted amateur who devoted himself to disproving the skeptics. A noted jazz musician in Norway, he rearranged his life to include eight long years of extraterrestrial sleuthing
His book, In Search of Stardust: Amazing Micro-Meteorites and Their Terrestrial Imposters,” due out in August, 2017, details the secret of his extraordinarily successful hunts. The book tells how Mr. Larsen taught himself to distinguish cosmic dust from the minuscule contaminants that arise from roads, shingles, factories, roof tiles, construction sites, home insulation and holiday fireworks.
Careful observers of the night sky are familiar with shooting stars—speeding bits of extraterrestrial rock that plunge through the Earth’s atmosphere, often burning up completely. The biggest can strike the ground, some forcefully enough to dig craters. In 2013, a relatively small rock exploded over the Russian city Chelyabinsk, releasing a shock wave that injured hundreds of people, mainly as windows shattered into flying glass.
But all that represents a tiny fraction of the downpour. Scientists say most of the cosmic material, known as micrometeorites, rain down on the planet continuously but have proved remarkably hard to find. Some bits are so small and lightweight that they drift down to Earth’s surface without melting.
The dust consists of tiny remnants from the Solar System’s birth, including debris from the lumps of dirty ice known as comets and from ages of smashups among planets and the big rocks known as asteroids. While most of the particles are interplanetary in nature, some contain grains of matter from outside the solar system, or true stardust. Their diversity makes them excellent windows on the cosmos.
Scientists have found micrometeorites mainly in the Antarctic, remote deserts and other places far from civilization’s haze. Starting in the 1940s and 1950s, investigators tried to find them in urban areas but eventually gave up because of the riot of human contaminants.
Significantly, it turns out that specialists trying to establish the cosmic origins of the tiny specks have tended to examine their chemical signatures rather than their overall appearance. That left a large opening for Mr. Larsen.
Mr. Larsen came to what he calls Project Stardust as a jazz guitarist in Norway, perhaps known best as the founder of Hot Club de Norvège, a string quartet. His group helped spur the global revival of gypsy jazz.
 William J. Broad, “Stardust Everywhere,” in the New York Time (Science Times, March 14, 2017, pp. D1, D3