Ancient Meteorite: Magnetic Fields Shaped Our Solar System

Magnetic fields may have played a crucial role in shaping our solar system, influencing the collapse of gas clouds and the formation of the protoplanetary disk even before the Sun fully coalesced. This is suggested by an analysis of the oldest matter particles preserved within an Antarctic meteorite.

Photo: Pravda.ru by Aleksey Rudnev, https://creativecommons.org/public-domain/pdm/

Meteorite over the forest

Scientists at the Massachusetts Institute of Technology (MIT) focused their research on calcium-aluminum-rich inclusions (CAIs) found in the DOM 08006 meteorite. These CAIs are considered the oldest objects in the solar system, having formed within the first 200,000 years of its existence.

Unlocking Magnetic History

To probe the distant past, the researchers employed paleomagnetism. Certain minerals within CAIs act as natural recorders, capturing the parameters of the surrounding magnetic field at the moment of crystallization or during intense heating events. The DOM 08006 meteorite was specifically chosen for its remarkable preservation; over 4.5 billion years, it has undergone minimal chemical and physical alteration, allowing the original magnetic "imprint" to remain intact.

The analysis revealed that the early solar nebula was permeated by a magnetic field significantly stronger than Earth's current magnetic field.

While gravity has traditionally been credited as the primary force transforming a spherical cloud of gas and dust into a flat disk with the Sun at its center, new findings point to the active participation of magnetism. This magnetism, generated by the movement of charged particles within the nebular plasma, appears to have created turbulence and directed matter flows. These "magnetic winds" may have facilitated the transfer of gas from the disk toward the nascent Sun, thereby regulating its mass.

Timing the Magnetic Imprint

The scientists are considering two scenarios for when these particles acquired their magnetic charge. The first suggests it occurred at the very initial moment of disk formation (or during brief heating bursts). The second possibility is that magnetization happened later, during the disk's evolution but before dust grains began clumping together to form larger bodies.

The core conclusion of the study is that magnetism was present in the solar system during the "disk" stage, prior to the commencement of planet formation. Previous data had only detected magnetic fields occurring 2 million years after the Sun's birth, by which time planetesimal formation was already underway.

Nevertheless, the current research is limited by data from a single meteorite. This reconstruction illustrates a potential scenario for our solar system but does not prove that all stellar systems form in the same way. To confirm the systemic nature of this phenomenon and rule out unique characteristics of DOM 08006, further analysis of similar inclusions in other primitive carbonaceous chondrites will be necessary.

Source: This commentary was adapted from an original Russian-language publication by Pravda.Ru.