Solar system 'not so special as thought'

Posted by Kate Taylor

Our solar system didn't, as previously thought, take twice as long as most to form, new research shows.

Some 4.567 billion years ago, planets were spawned from the wide disk of gas and dust rotating around the sun. While this is the same way that other, younger solar systems form, our own was believed to have taken much longer over the process.

However, new research led by the Centre for Star and Planet Formation at the Natural History Museum of Denmark, University of Copenhagen, suggests otherwise.

Using improved methods of analysis of uranium and lead isotopes, the study of primitive meteorites has allowed researchers to date the formation of two very different types of materials: calcium-aluminum-rich inclusions (or CAIs for short) and chondrules, found within the same meteorite.

They are our solar system's very oldest materials, but it had been thought that CAIs were around two million years older than chondrules.

But while the study confirmed previous analyses demonstrating that CAIs were formed during a very short period of time, it also concluded that chondrules were formed during the first three million years of the solar system's development as well.

"By using this process to date the formation of these two very different types of materials found in the same meteorite, we are not only able to alter the chronology of our solar system's historical development, we are able to paint a new picture of our solar system's development, which is very much like the picture that other researchers have observed in other planetary systems," says James Connelly of the Centre for Star and Planet Formation.

The findings addresses the question of why chondrule formation should be delayed by up to two million years after that of the CAIs. The answeris simply that it isn't.

"In general, we have shown that we are not quite as unique as we once thought. Our solar system closely resembles other observable planetary systems within our galaxy," says says Professor Martin Bizzarro, head of the Centre for Star and Planet Formation.

"In this way, our results serve to corroborate other research results which indicate that earth-like planets are more widespread in the universe than previously believed."