photomicrogrphs of space dust
© Jan Braly Hihle/Jon Larsen
Varieties of space dust, barely width of human air
After decades of failures and misunderstandings, scientists have solved a cosmic riddle — what occurs to the tons of dust particles that hit the Earth each and every day but seldom if ever get found in the locations that humans know very best, like buildings and parking lots, sidewalks and park benches.

The answer? Absolutely nothing. Appear harder. The tiny flecks are everywhere.

An international group identified that rooftops and other cityscapes readily gather the extraterrestrial dust in techniques that can ease its identification, contrary to science authorities who long pooh-poohed the concept as little far more than an urban myth kept alive by amateur astronomers.

Remarkably, the leader of the discovery team — and co-author of a recent paper in Geology, a monthly journal of the Geological Society of America — turns out to be a gifted amateur who devoted himself to disproving the skeptics.

A noted jazz musician in Norway, he rearranged his life to consist of eight long years of extraterrestrial sleuthing. His hunt has now produced a significant discovery, a colorful book for lay readers and what scientists get in touch with a portrait gallery of alien guests.

"I hope and believe this will begin something," the musician, Jon Larsen, said in an interview. His objective? "Making it straightforward."

His book, "In Search of Stardust: Remarkable Micro-Meteorites and Their Terrestrial Imposters," due out in August, specifics the secret of his extraordinarily productive hunts. Its 150 pages and 1,500 photomicrographs, or photos taken by way of a microscope, inform how Mr. Larsen taught himself to distinguish cosmic dust from the minuscule contaminants that arise from roads, shingles, factories, roof tiles, building sites, home insulation and vacation fireworks.

As his book puts it, "To pick out one particular extraterrestrial particle among billions of other people needs understanding both about what to appear for and what to disregard."

The diminutive flecks to which Mr. Larsen, 58, has devoted himself represent the smallest components of a cosmic downpour that has lashed the Earth for billions of years.

Cautious observers of the evening sky are familiar with shooting stars — speeding bits of extraterrestrial rock that plunge by way of the Earth's atmosphere, usually burning up entirely. The largest can strike the ground, some forcefully adequate to dig craters. In 2013, a fairly little rock exploded over the Russian city Chelyabinsk, releasing a shock wave that injured hundreds of folks, mostly as windows shattered into flying glass.

But all that represents a tiny fraction of the downpour. Scientists say most of the cosmic material is remarkably tiny — barely the width of a human hair. Identified as micrometeorites, they rain down on the planet a lot more or much less continuously but have proved remarkably challenging to find. Some bits are so tiny and lightweight that they drift down to the Earth's surface without having 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 amongst planets and the large rocks recognized as asteroids. Even though most of the particles are interplanetary in nature, some contain grains of matter from outdoors the solar technique, or true stardust. Their diversity tends to make them excellent windows on the cosmos.

Scientists have found micrometeorites mainly in the Antarctic, remote deserts and other locations far from civilization's haze. Starting in the 1940s and 1950s, investigators tried to discover them in urban areas but ultimately gave up due to the fact of the riot of human contaminants.

Considerably, it turns out that specialists attempting to establish the cosmic origins of the tiny specks have tended to examine their chemical signatures rather than their all round appearance. That left a massive opening for Mr. Larsen.

Matthew J. Genge, one of the Geology paper's 4 authors and a senior lecturer in earth and planetary science at Imperial College, London, used an electron microprobe at the Natural History Museum in London to decide the chemical makeup of Mr. Larsen's finds and confirm their cosmic origin.

In an interview, he said that, more than all, the grains that survive the atmospheric plunge and land on the Earth's surface add up to far more than 4,000 tons annually, or much more than ten tons a day. "He's completed a useful factor in classifying the contaminants," Dr. Genge said of Mr. Larsen's perform. "It has wide-reaching implications."

Donald E. Brownlee, an astronomer at the University of Washington who helped establish the field, called Mr. Larsen a correct citizen scientist whose perform will help the worldwide hunt for the tiny specks.

"Your automobile is covered with cosmic dust," Dr. Brownlee mentioned. "We inhale this stuff. We consume it every time we consume lettuce. But usually, it's incredibly challenging to discover."

Mr. Larsen came to what he calls Project Stardust as a jazz guitarist in Norway, possibly identified greatest as the founder of Hot Club de Norvège, a string quartet. His group helped spur the international revival of gypsy jazz.

As Mr. Larsen tells the story, he was an enthusiastic rock collector as a kid but did so effectively as a musician that he set aside his early scientific ambitions. Then, in 2009, at a country house outside Oslo, he was cleaning an outside table when a bright speck caught his eye.

"It was blinking in the sunlight," he recalled. He touched the fleck. "It was angular in some way, kind of metallic but so small — a tiny dot."

Intrigued, Mr. Larsen suspected it was a cosmic visitor and began to look for a lot more. He collected dust samples from Oslo and cities about the globe, moonlighting as a scientist while vacationing or touring with his jazz group. He took samples from roads, roofs, parking lots and industrial areas.

Place indelicately, he collected hundreds of pounds of dreck — sludge from drains, gutters and downspouts, the dregs of civilization that most individuals try to keep away from.

"Still, I didn't find a single micrometeorite," he recalled. "It was quite frustrating."

Mr. Larsen then changed tactics. Rather than seeking exclusively for cosmic dust, he taught himself how to classify the dozens of diverse kinds of earthly contaminants, starting a procedure of elimination that slowly narrowed the candidates and raised the possibilities that some tiny fraction of the urban debris may turn out to belong to the cosmos.

The breakthrough came two years ago. In London, Dr. Genge studied 1 of the gathered particles — from Norway, not Timbuktu — and confirmed that it was certainly a traveler from outer space. Mr. Larsen swiftly identified hundreds a lot more.

"Once I knew what to look for, I found them everywhere," he stated.

In the Geology paper, the scientific group reports the discovery of about 500 micrometeorites — collected primarily from roof gutters in Norway — and tells of the detailed evaluation of 48 of the extraterrestrial specks. The group involves two of Dr. Genge's students, Martin D. Suttle of Imperial College and Matthias Van Ginneken of the Université Libre in Brussels.

The group described the cosmic dust as the youngest collected to date, since gutters have a tendency to get cleaned fairly often. Also, urban surfaces are current arrivals in the worldwide landscape compared to polar ice and ancient deserts.

In his travels, Mr. Larsen lately visited with Michael E. Zolensky, an extraterrestrial components scientist in Houston at the Johnson Space Center of the National Aeronautics and Space Administration. They not only talked shop but also went up to the roof of the large constructing that homes rocks from the Apollo moon program.

"It was pretty cool," Dr. Zolensky said. "The curation building is now a collector of cosmic dust."

In an interview, Mr. Larsen described his technique — sorting through the contaminants in a method of elimination — as "something that anyone can do. It could and ought to become part of teachings in schools, an aspect of citizen science."

Dr. Brownlee of the University of Washington agreed. He stated that, whilst several schools try to find cosmic dust particles in programs meant to make science classes a lot more inviting and accessible, handful of if any succeed. "It could assist a lot," he stated of Mr. Larsen's strategy. "For education, it's pretty cool."

Dr. Genge of Imperial College said Mr. Larsen's methods, if adopted widely, may possibly also open a new lens on the cosmos.

The gravitational pull of the planets, he noted, seem to tug on the dust clouds of the solar system and gradually change their orbits. He mentioned a wave of new terrestrial finds could support scientists much better map the clouds, raising far more queries for science about the structure of the universe.

"I think about my microscope a telescope," Dr. Genge stated. "It can give you a quite huge image."