Scientists say the solar system was formed in less than 200,000 years

Scientists often talk about the cosmic time scale. For humans, a decade is often seen as a long time. On a cosmic time scale, 10 years or even a hundred years is a blink of an eye. Cosmic time scales are measured in millions or billions of years. Scientists from Lawrence Livermore National Laboratory recently announced that research indicates that our solar system was formed in less than 200,000 years.

On a cosmic scale, it is very fast. The researchers came to this conclusion after examining the isotopes of the element molybdenum found in meteorites. The material makes up the sun and the rest of the solar system and comes from the collapse of a large cloud of gas and dust about 4.5 billion years ago. By observing other solar systems that formed similarly to our own solar system, astronomers were able to estimate that it probably took 1 to 2 million years for the cloud to collapse and a star to ignite.

Before this study, the period of formation of the solar system was not clearly known. The new research shows that the collapse of the gas cloud that led to the formation of the solar system happened very quickly, in less than 200,000 years. To put this time frame into a better perspective, the project scientists say that if we scale it down to compare it to human pregnancy, the pregnancy will last around 12 hours instead of nine months.

The oldest dated solids in the solar system are calcium-aluminum-rich inclusions (CAI). The samples provide a direct record of the formation of our solar system. CAIs are two-centimeter micrometric inclusions and meteorites that formed at high temperatures of over 1300 degrees Kelvin, probably near the young sun.

The CAI were then transported outwards to a region where meteorites of carbonaceous chondrite were formed. Most of the CAI was formed 4.567 billion years ago, in a period between about 40,000 and 200,000 years. By measuring the isotopic and trace element compositions of molybdenum various CAI from carbonaceous chondrite meteorites, the team found that the distinct isotopic compositions of CAI cover the full range of material that formed in the protoplanetary disk instead of a small slice. This means that the inclusions must have formed within the time frame of the cloud collapse.