By analyzing the oxygen isotopes (varieties of an element that have some extra neutrons) of these refractory inclusions, the research team has determined that the differences in composition between the sun, planets and other solar system materials were inherited from the protosolar molecular cloud that existed even before the solar system. The results of their study have been recently published in Science Advances.

"It has been recently demonstrated that variations in isotopic compositions of many elements in our solar system were inherited from the protosolar molecular cloud," said lead author Alexander Krot, of the University of Hawaii. "Our study reveals that oxygen is not the exception."

Molecular cloud or solar nebula?

When scientists compare oxygen isotopes 16, 17 and 18, they observe significant differences between the Earth and the sun. This is believed to be due to processing by ultraviolet light of carbon monoxide, which is broken apart leading to a large change in oxygen isotope ratios in water. The planets are formed from dust that inherits the changed oxygen isotope ratios through interactions with water.

What scientists have not known is whether the ultraviolet processing occurred in the parent molecular cloud that collapsed to form the proto-solar system or later in the cloud of gas and dust from which the planets formed, called the solar nebula.

To determine this, the research team turned to the most ancient component of meteorites, called calcium-aluminum inclusions (CAIs). They used an ion microprobe, electron backscatter images and X-ray elemental analyses at the University of Hawaii's Institute of Geophysics and Planetology to carefully analyze the CAIs. They then incorporated a second isotope system (aluminum and magnesium isotopes) to constrain the age of the CAIs, making the connection - for the first time - between oxygen isotope abundances and mass 26 aluminum isotopes.

From these aluminum and magnesium isotopes, they concluded that the CAIs were formed about 10,000 to 20,000 years after the collapse of the parent molecular cloud.

"This is extremely early in the history of the solar system," said Lyons, who is an associate research professor at ASU's School of Earth and Space Exploration, "so early that there would not be enough time to alter oxygen isotopes in the solar nebula."

Although more measurements and modeling work are needed to fully assess the implications of these findings, they do have implications for the inventory of organic compounds available during solar system and later planet and asteroid formation.

"Any constraint on the amount of ultraviolet processing of material in the solar nebula or parent molecular cloud is essential for understanding the inventory of organic compounds that lead to life on Earth," Lyons said.

Research paper

Related Links
Arizona State University
Stellar Chemistry, The Universe And All Within It

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Modelling extreme magnetic fields and temperature variation on distant stars
Leeds UK (SPX) Oct 14, 2020
New research is helping to explain one of the big questions that has perplexed astrophysicists for the past 30 years - what causes the changing brightness of distant stars called magnetars. Magnetars were formed from stellar explosions or supernovae and they have extremely strong magnetic fields, estimated to be around 100 million, million times greater than the magnetic field found on earth. The magnetic field generates intense heat and x-rays. It is so strong it also affects the physical p ... read more