| EXPLORE | SPACE
HOW SMALL?
Each particle is about
300 microns wide,
roughly the width of a
human hair. To capture
tiny details, Lar sen and
colleague Jan Kihle
shoot with varied focal
lengths, taking one photo
per micron. Software
combines the images.through Earth’s atmosphere, first melt-
ing and then solidifying. The examples
shown here—from Larsen’s new book,
In Search of Stardust—exhibit swirling
ridges, golden spots of iron-nickel metal
and sulfide, and crystal pyramids of min-
erals, which formed during the journey.
Larsen was able to find micromete-
orites by washing the sludge that had
accumulated in open roof gutters, sifting
it, and then using a magnet to extract
particles from the remaining grit. After
approaching many scientists, he finally
persuaded Matthew Genge, a planetary
scientist at Imperial College London, to
examine 48 particles he had collected.
Genge analyzed their composition and
confirmed that Larsen had indeed man-
aged to find extra terrestrial dust amid
earthly debris. “Jon was the one staring
down the microscope,” says Genge, “go-
ing through hundreds of thousands of
particles to find just one micrometeorite.”A Norwegian jazz musician and citizen
scientist, Jon Larsen has figured out how
to do something the experts thought
was impossible—find specks of cosmic
dust, called micrometeorites, amid the
detritus of human habitation. Scien-
tists look for these particles, which rain
down constantly on Earth, in Antarctica
and other pristine locations, but Larsen
thought there should be a way to collect
them in more populated places.
Some micrometeorites are real
stardust— flecks from exploded stars.
Others are likely created when aster-
oids collide and comets vaporize. Larsen
learned to identify the unique features
that take shape as the specks plummetWHERE STARDUST
HIDES ON EARTHBy A. R. WilliamsSTACKED MICROSCOPE PHOTOS: JAN BRALY KIHLE AND JON LARSEN