The recent scientific finding that has been making waves in the astronomical community is the discovery of presolar grains of Silicon Carbide (SiC) in the Murchison meteorite. This meteorite fell in Australia in the year 1969, and upon analysis, these SiC grains were found to be between 4.6 and 7 billion years old. This makes them the oldest solid materials ever found on Earth.
The Significance of Presolar Grains
The presolar grains of Silicon Carbide are a significant discovery as they predate the formation of our solar system, thus justifying their name ā “presolar grains”. Their rarity adds to their importance, as they are only present in about 5% of meteorites that have fallen onto our planet. Apart from their antiquity and rarity, these presolar grains also have major scientific implications. They may unlock secrets about the mysterious phenomenon of star formation in our Milky Way Galaxy.
The Connection to Stardust
The silicon carbide grains discovered in the meteorite are essentially fragments of stardust, that is, the remains of space material expelled from stars. This stardust is then carried into interstellar space by stellar winds, which are flows of gas ejected from stars’ upper atmospheres. Interstellar space is defined as the region beyond a magnetic zone that extends approximately 122 Astronomical Units from the sun.
During the birth of the solar system, this stardust was incorporated into the entities that were forming, including the planets and the sun. However, this material has managed to remain intact only in asteroids and comets until now.
| Fact | Description |
|---|---|
| Age of Presolar Grains | 4.6 to 7 billion years |
| Composition of Presolar Grains | Silicon Carbide (SiC) |
| Presence in Meteorites | Found only in about 5% of meteorites |
| Connection to Stardust | Composed of ancient stardust |
About Silicon Carbide (SiC)
Silicon carbide, also known as carborundum, is a compound formed by silicon and carbon. This compound is a semiconductor material that is increasingly finding applications in semiconductor devices. Its importance extends further as it is one of the primary industrial ceramic materials used today. Apart from being used in semiconductors, silicon carbide is also used widely as an abrasive, steel additive, and as a structural ceramic.
With the recent discovery of these ancient presolar grains, our understanding of interstellar space, star formation, and the history of our solar system could potentially be revolutionized.