Laboratory measurements of magnetic fields trapped in grains of a primitive meteorite provided insight into how our solar system evolved.
The findings point to shock waves traveling through a cloud of dust around the newborn Sun as a major contributor to the formation of the solar system that gave birth to our home planet, Arizona State University reported. The researchers report the findings are "astounded and unprecedented."
"Not only have they measured tiny magnetic fields thousands of times weaker than a compass feels, they have mapped the magnetic fields' variation recorded by the meteorite, millimeter by millimeter, said co-author Steve Desch of Arizona State University's School of Earth and Space Exploration.
To make these fascinating findings the researchers looked at chondrites, which are pieces of asteroids that broke off during an ancient collision; these objects have remained relatively unmodified since they formed during the birth of our solar system.
The chondrites are composed of primarily of small grains called chondrules, which formed through quick melting processes in the solar nebula surrounding the infant Sun. As the chondrules cooled the iron-bearing minerals within them became magnetized by the local magnetic field in the gas.
"The new experiments," Desch said, "probe magnetic minerals in chondrules never measured before. They also show that each chondrule is magnetized like a little bar magnet, but with 'north' pointing in random directions."
These findings suggest these bits became magnetized before they were built into the meteorite, as opposed to while resting on Earth's surface.
"My modeling for the heating events shows that shock waves passing through the solar nebula is what melted most chondrules," Desch said. Depending on the strength and size of the shock wave, the background magnetic field could be amplified by up to 30 times."
The study's conclusions back up the idea that shocks melted the chondrules in the region that is now our asteroid belt.
"This is the first really accurate and reliable measurement of the magnetic field in the gas from which our planets formed," Desch saod.
The findings were published Nov. 13 in the journal Science.
