The Absolute Cosmos: In a first, scientists identified the time duration of our solar system formation

A group of scientists from Lawrence Livermore National Laboratory (LLNL) have identified the duration of solar system formation.

Roughly about 4.5 billion years ago a large dense interstellar cloud of dust and gas collapsed, providing the material responsible for making Sun and rest of the solar system.

It likely takes about one/two millions years for the interstellar cloud to collapse and fire up the star. Scientists calculate this by studying other stellar systems which were formed in similar way like our solar system.

This is for the first time that a study has provided the time duration of our solar system’s formation. This new study shows that the interstellar cloud collapse, which steered the solar system formation, happened at incredibly fast pace, in less than 200,000 years.

Calcium-aluminum-rich inclusions (CAIs) are the oldest solids in our solar system. These small metallic droplets were later incorporated into meteorites.

The ages of CAIs are thought to be the age of our solar system. However, which exact moment in formation of star they correspond to has not been clear. CAIs were probably formed near the young Sun in high temperature zone.

Later, they got transported outward to the zone where carbonaceous chondrite meteorites were formed. Most of these CAIs were formed 4.567 billion years ago over a span of about 40,000–200,000 years.

Scientists from LLNL calculated the molybdenum (Mo) isotopic and trace element compositions of various CAIs taken from chondrite meteorites, including the largest carbonaceous chondrite found on our planet, Allende.

The inclusions probably have formed within the time duration of cloud collapse because scientists found that the distinct isotopic compositions of CAIs cover the entire range of material formed in the protoplanetary disk rather than just a small portion.

As the observed time duration of stellar accretion is 1–2 million years, which is much longer than CAIs took to form, scientists were able to point out the astronomical stage in formation of solar system in which formation of CAIs was recorded, and eventually how fast the material (which makes up the solar system) accreted.

For more information: Astronomical context of Solar System formation from molybdenum isotopes in meteorite inclusions

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