The spotlight is on the recent research carried out on a meteorite from Katol, Maharashtra, originated from a meteor shower in 2012. The significant findings unearthed from this research provide insightful data regarding the depth of Olivine, the formation of Bridgmanite, and the planetary evolution process.
Unraveling the Depth of Olivine
The primary composition of the examined meteorite was found to be olivine, an olive-green mineral which is predominantly present in the Earth’s upper mantle. The earth’s structure consists of distinct layers, starting with the outer crust, followed by the mantle and then the inner core. It was previously believed that the upper mantle could be reached after drilling approximately 410 kilometers into the earth’s surface.
However, this study has shattered that belief by revealing the composition which is expected to be found in the Earth’s lower mantle located at an approximate depth of 660 km. This data was obtained through intensive scrutiny of the meteorite fragments.
The Formation of Bridgmanite and its Significance
Numerous computational and experimental studies have posited that about 80% of the Earth’s lower mantle comprises bridgmanite. By examining the Katol meteorite sample, researchers are able to decipher how bridgmanite crystallized during the concluding stages of the Earth’s formation.
A magnesium-silicate mineral, bridgmanite (MgSiO3), enjoys the title of being the most abundant mineral on earth. The mineral was christened in 2014, honoring Prof. Percy W. Bridgman, the recipient of the 1946 Nobel Prize in Physics. Interestingly, the bridgmanite present in the Katol meteorite closely aligns with earth’s bridgmanite.
It is important to note that the meteorite’s bridgmanite was formed under pressures ranging from 23 to 25 gigapascals, as a result of the meteorite’s shocking entry into earth’s atmosphere. Over billions of years, earth’s interior has undergone drastic changes in temperature and pressure, leading to the crystallization, melting, and remelting of different minerals before achieving their current state.
Studying Meteorites: The gateway to Planetary Evolution
The study of this meteorite not only provides information about its composition but also sheds light on Earth’s evolutionary journey from a magma ocean to a rocky planet. Such research enables scientists to dig deeper into Earth’s formation process. Studying these discrete minerals individually contributes significantly to understanding how Earth’s layers were formed and when.
How did the Inner Planets Form?
The inner planets or terrestrial planets, namely Mercury, Venus, Earth, and Mars, are believed to have formed through a process called accretion. Accretion refers to the coming together of rocky fragments, forming a planet under high pressure and temperature caused by radioactive elements and gravitational forces.
Initially, Earth was like an ocean of magma before the elements crystallized and stabilized to form distinct layers such as the core, mantle, and crust. The heavier elements like iron sank and formed the core while the lighter silicates stayed at the top, constituting the mantle.
