According to a recent study by scientists from the California Institute of Technology, the analysis of a meteorite shows that the Earth’s building blocks and planetary “seeds” contain water.
As per the statement from the California Institute of Technology, researchers state that when our sun was a young star 4.56 billion years ago, our solar system was just a disk of rocky debris and gas. Over tens of millions of years, tiny specks of dust accumulated like a snowball rolling larger and larger, forming “mini-planets” about the size of a kilometer, which constituted the Earth’s building blocks.
The scientists published their study results in the journal Nature Astronomy titled “Accretion of the oldest small planets in the inner solar system outside the snow line.”
Understanding Planetary Ancient Environments
According to the statement from the California Institute of Technology, researchers have long sought to understand the ancient environments in which these mini-planets formed, to determine if they contained water.
According to the planetary formation theory, mini-planets are solid bodies surrounding a newly formed star, forming from cosmic dust grains clumping together to form larger and larger bodies (similar to a snowball).
To address these questions, scientists at the California Institute of Technology analyzed samples of meteorites believed to date to the earliest years of the solar system, formed from the metal cores of the oldest mini-planets in our solar system, which eventually fell to our planet.
Results of Meteorite Analysis
After analyzing the meteorites, the study found that the oldest mini-planets in the inner solar system formed in the presence of water, challenging current astronomical physical models of the early solar system.
The study also concluded that the chemical compositions of such meteorites can reveal information about the environments in which they formed, to determine whether the Earth’s building blocks formed far from our sun, where cold temperatures allowed for the existence of water ice, or formed closer to the sun, where heat could evaporate any water and lead to the desiccation of the mini-planets.
The California University statement adds that although the meteorites themselves do not contain water, scientists can infer its long-lost presence through examining its impact on other chemical elements.
Additionally, scientists analyzed the presence of water previously through our prior knowledge that water consists of two hydrogen atoms and one oxygen atom, and in the presence of other elements, water’s oxygen atom is often transferred in a process called oxidation.
Iron Meteorites
Regarding the importance of iron meteorites, Professor of Geology and Geochemical Chemistry Paul Asimow says, “Iron meteorites have been somewhat neglected by the planet formation community, but they represent rich reservoirs of information about the earliest phase of solar system history. Once you figure out how to read the signals, the difference between what we measured in the inner solar system from what we expected means that there was about 10,000 times more oxygen activity.”
In conclusion, the study found that these iron meteorites believed to derive from the inner solar system contain the same amount of missing iron mineral as the meteorites derived from the outer solar system.
The presence of water in these ancient mini-planets challenges many current astronomical physical models of the solar system, indicating that the seeds of planets accumulated water from the start, challenging the current understanding of the solar system. If the mini-planets formed in the current Earth’s orbital location, there would be no water unless the inner solar system was much colder than expected by current models, or they may have formed farther out where the atmosphere was cooler, then migrated inward.
Griwal, the lead author of the study and a researcher at the California Institute of Technology, suggests that if water was present in the Earth’s first building blocks, it’s likely that other important elements like carbon and nitrogen were also present, potentially constituting life’s components from the beginning.
