Meteorites brought volatile compounds to Earth that were essential for the emergence of life, Volatiles are elements or compounds that change into vapor at relatively low temperatures.
Researchers, from the University of Cambridge and Imperial College London, have previously found that Earth’s zinc came from different parts of our Solar System: about half came from beyond Jupiter and half originated closer to Earth.
“One of the most fundamental questions on the origin of life is where the materials we need for life to evolve came from,” said Dr Rayssa Martins from Cambridge’s Department of Earth Sciences. “If we can understand how these materials came to be on Earth, it might give us clues to how life originated here, and how it might emerge elsewhere.”
Planetesimals are the basic building blocks of rocky planets, including Earth. But not all planetesimals are created equal. The earliest planetesimals in the solar system were exposed to high radiation levels, which caused them to melt and lose their volatiles. However, some planetesimals escaped high doses of radiation and retained more volatiles. The latter includes the six most common elements found in living organisms and water. according to a study published in the journal Science Daily.
The scientists analyzed the zinc from planetesimals that had reached the Earth’s surface. Early “melted” planetesimals made up about 70% of the Earth’s total mass, but provided only about 10% of its zinc reserves. A more important source of zinc was late planetesimals that did not melt and lose their volatiles. These planetesimals were also an important source of volatiles for the Earth.
The work will help improve the search for life on other planets.
“We know that the distance between a planet and its star is a determining factor for maintaining liquid water on its surface. But our results show that there is no guarantee that such planets have the ingredients to support enough water and other volatiles,” the authors noted.
