Fragments of an ancient meteorite may hold the key to understanding how the solar system evolved. A team of researchers recently made the most accurate ever measurements of this meteorite, and found that there are signs of a magnetic field in particles called chondrules embedded in another meteorite. This means that the early solar system likely had a strong magnetic field, and this may be one of the ways how our solar system formed initially.
This research study was published November 13 in the journal Science.
Steve Desch, one of the co-authors of the paper, described how extraordinary these detailed measurements are. Roger Fu, the lead author of the paper, and his supervisor, Benjamin Weiss, tracked the magnetic field's variation throughout the meteorite, even though the fields they picked up are extremely weak.
The meteorite that the team studied contained grains from a type of meteor called a chondrite, one of the earliest forms of meteorite, believed to be debris from the formation of the solar system 4.5 billion years ago. They studied eight chondrules from a meteorite named Semarkona that fell to Earth in 1940.
"Only a few meteorites in our entire collection can work for a study like this," Fu said.
By the time most meteorites get to Earth, the magnetic information they carry has been wiped out by heat and wetness. The meteorite this team tested seems to have stayed mostly dry and cool since the dawn of the solar system, meaning that it carries all of its information. This meteorite has never been studied before. The team found that this meteorite points to an early solar system with a magnetic field much stronger than the one today.
"The magnetic field that we measure [in the chondrules] is extremely strong-10,000 times stronger than what's in interplanetary space today. It's hard to imagine it didn't play a major role in mass and angular momentum transfer," Weiss said.
The team said that its evidence points to shocks in the solar nebula melting these chondrules, and possibly multiplying the magnetic field by up to 30 times. They estimated that the magnetic field in the solar system was probably between 5 to 50 microtesla.
