So - called magnetotactic bacteria create a chain
of magnetite grains to help orient themselves in their search for nutrients.
Not exact matches
The meteorite is full
of grains of an iron oxide mineral called
magnetite, each
grain a mere 20 to 120 nanometers across.
When the scientists examined the cells in the growing communities closely, they found nanoparticles
of magnetite on the surface
of cells and, in some cases,
grains of the iron mineral connecting microbial pairs.
He and Kent used a bandsaw to trim the samples into sugar cube - size blocks and inserted them into a magnetometer, which measured the polarity
of tiny
grains of the minerals hematite and
magnetite contained in the sediment.
Microscopic
grains inside
magnetite are capable
of storing information about the planet's magnetic field, including the direction and intensity, from the time the minerals cooled and solidified.
However, the
magnetite grains found in the carbonate globules
of ALH84001 have very few
of these sorts
of substitutions.
In 2001, she and her colleagues showed that many
of the same properties in biologically - derived
magnetite are reproduced in the
grains from ALH84001.
It's improbable that Martian microbes deposited
magnetite grains directly in the rock, so Thomas - Keprta and her colleagues have to argue that the
magnetite formed outside
of the rock and washed in.
In the end, she helped the team characterize the biomorphic features, as well as unusual
grains of the mineral
magnetite found in the meteorite.