When the earliest rocks were formed in the solar system, they looked more like candy floss than the hard rock that we know today, according to a new research.
Researchers from Imperial College London and other international institutions made the discovery after highly detailed analysis of a meteorite fragment from the asteroid belt between Jupiter and Mars.
The ‘carbonaceous chondrite meteorite’ was originally formed in the early solar system when microscopic dust particles gathered around larger grain particles called chondrules, which were around one mm in size.
The study provides the first geological evidence to support previous theories, based on computer models and lab experiments, about how the earliest rocks were formed.
The findings show that the first solid material in the solar system was fragile and extremely porous – much like candy floss – and that it was compacted during periods of extreme turbulence into harder rock, forming the building blocks that paved the way for planets like Earth.
“Our study makes us even more convinced than before that the early carbonaceous chondrite rocks were shaped by the turbulent nebula through which they travelled billions of years ago, in much the same way that pebbles in a river are altered when subjected to high turbulence in the water. Our research suggests that the turbulence caused these early particles to compact and harden over time to form the first tiny rocks,” said Phil Bland, lead author of the study from the Department of Earth Science and Engineering at Imperial College London.
The scientists used an electron backscatter defraction technique to To analyse the carbonaceous chondrite sample.
This technique enabled the researchers to study the orientation and position of individual micrometre-sized grain particles that had coalesced around the chondrule.
They were able to estimate the amount of compression the rock had experienced, allowing them to deduce its original fragile structure.
“What''s exciting about this approach is that it allows us – for the first time – to quantitatively reconstruct the accretion and impact history of the most primitive solar system materials in great detail. Our work is another step in the process helping us to see how rocky planets and moons that make up parts of our Solar System came into being,” said Bland.
The study is published in the journal Nature Geoscience.