WWW.ASTRONOMY.COM 29
aren’t micrometeorites. These are
something else.’ ”
Then, Suttle and his adviser,
Imperial College planetary geolo-
gist Matthew Genge, took another
look. This time, they noticed that
the minerology was more familiar
than it had seemed at first glance.
The relative ratios were right. But
the manganese was where the
nickel was supposed to be.
The pair also
found that, while the
grains looked like
micrometeorites, they
contained tiny f laws. They had
small growths and protrusions
— something often seen in fossils
when the minerals replacing
organic material aren’t an exact
1-to-1 match. Suttle and Genge
began to form a hypothesis:Perhaps the spherules
were simply fossilized
micrometeorites.Cosmic time capsules
“It was a gradual realization,”
Suttle says. “It was entirely
plausible that these particles,
when they were embedded in
the seaf loor mud, had been
altered through diagenesis,” theColliding asteroids,
such as those seen in
this artist’s concept,
create huge amounts
of tiny dust particles,
which can eventually
rain down on Earth
as micrometeorites.
NASA/JPL-CALTECH/R. HURT