The solar system that we live in is thought to have formed roughly 4.567 billion years ago, with the planets created out of an enormous disc of dust and gas in rotation around the sun. Similar processes are often observed around younger star systems all throughout the Milky Way, but until now it had been thought that the formation of our system had been an outlier, taking twice as long to form.
But now, new research done using the uranium and lead dating of a type of primitive meteorite thought to have formed with the planets has suggested otherwise.
“Using improved methods of analysis of uranium and lead isotopes, the current study of primitive meteorites has enabled researchers to date the formation of two very different types of materials, so-called calcium-aluminum-rich inclusions (or CAI’s for short) and chondrules, found within the same meteorite. By doing so, the chronology and therefore overall understanding of our solar system’s development has been altered.”
For the new work, the researchers took a closer look at the first 3 million years of the solar system’s development “by analysing primitive meteorites composed of a blend of our solar system’s very oldest materials. In part, the study confirmed previous analyses demonstrating that CAI’s were formed during a very short period of time. The new discovery is that the so-called chondrules were formed during the first three million years of the solar system’s development as well. This stands in contrast with previous assumptions asserting that chondrules only started forming roughly two million years after CAIs.”
“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.
By clarifying that chondrules are the same age as CAIs, the old question of why chondrule formation should only occur around 2 million years after CAIs has finally been answered. They don’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. 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,” says Professor Martin Bizzarro, head of the Centre for Star and Planet Formation.
The new research was just published in the journal Science.
Source: University of Copenhagen
Image Credits: NASAR illustration; NASA/JPL-Caltech/T.Pyle (SSC)/Mia Olsen