Researchers have been attempting to discover physical evidence supporting their beliefs that strong magnetic fields may have been at the center of our solar system’s formation. A unique meteorite has finally made their wishes come true.
The Semarkona meteorite is particularly valuable to scientists because it, as opposed to other metorites, has not suffered alterations throughout its long journey to Earth and consequently, it maintains its original magnetization. The meteorite is made up of chondrules- tiny, round pellets formed as molten droplets which have undergone a quick cooling process in space.
“Chondrules themselves created through quick melting events within the dusty gas cloud — the solar nebula — that encircled the young sun. As chondrules cooled, iron-bearing minerals within them became magnetized like bits on the hard disk through the local magnetic field in the gas. These magnetic fields are maintained within the chondrules even down to the current day,”
Semarkona’s chondrules have iron-bearing minerals in their composition and as such, they have recorded the magnetic fields that were present at the time when our solar system was forming. This was happening approximately 4.6 billion years ago and, after our sun formed, the dense rotating disk of gas and dust that was surrounding the young star began to merge forming today’s planets.
These strong magnetic fields present at our solar system’s birth are believed to have an impact in accelerating the process through which the protoplanetary disk surrounding the new-born star would be absorbed into the sun. Researchers theorized that the magnetism could have introduced viscosity into the disk, which would have made the gas stickier. Roger Fu, planetary scientist at MIT at Cambridge, Massachusetts, is one of the scientists adhering to this theory.
This increased viscosity would have caused gas found on specific orbits to strongly interact with each other. Consequently, more gas would be attracted to the star.
The Semarkona meteorite offers keen evidence in support of this theory. Scientists explain that Semarkona is essentially a primitive meteorite, believed to have formed 4.5 billion years ago. It has also preserved the properties it had at the time of its formation.
“This is the first direct information we have on the magnetic fields in the early solar system. It’s a really difficult measurement that was very cleanly performed — it stands out as a real tour de force.”
Mordecai Mac Low, astrophysicist, explains.