(ORDO NEWS) — Researchers at Imperial College London have reported the likely origin of Earth‘s volatile chemicals, some of which form the building blocks of life.
Scientists have found that about half of the volatile element zinc came to Earth from asteroids originating from the outer solar system.
Volatile substances are elements or compounds that change from solid or liquid to vapor at relatively low temperatures. They include the six most common elements found in living organisms, as well as water.
Prior to this, researchers believed that most of the terrestrial volatiles were obtained from asteroids that formed closer to the Earth.
New evidence suggests that the outer solar system played a larger role than previously thought.
The scientists studied 18 meteorites of various origins – eleven non-carbonaceous meteorites from the inner solar system, and seven carbonaceous meteorites from the outer solar system.
The researchers measured the relative abundance of five zinc isotopes in each meteorite.
They then compared each isotopic fingerprint with samples from Earth to determine how much each of these materials contributed to our planet’s zinc supply.
The results show that although the Earth is only about 10% carbonaceous, this material provides about half of the Earth’s zinc.
The researchers say the material with high concentrations of zinc and other volatiles is also likely to be found in relative abundance in the water, providing clues to the origin of Earth’s water.
“We have known for a long time that some carbonaceous material was added to Earth, but the results show that this material played a key role in establishing our balance of volatile elements, some of which are essential for life to flourish,” said Raissa Martins, first author of the paper.
The researchers also plan to analyze rocks from Mars that contained water 4.1 to 3 billion years ago, and from the Moon.
“A widely accepted theory is that the Moon was formed when a huge asteroid crashed into the embryonic Earth about 4.5 billion years ago.
Analysis of zinc isotopes in lunar rocks will help us test this hypothesis and determine whether this asteroid played an important role in delivering volatiles, including water, to Earth, ”the scientists said.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.