Stopwatch found for Solar System
By Sudeep Chand
Science reporter, BBC News
Electron picture of a chondrule, part of a meteorite 4.5 billion years old
Scientists have found a new way to time events in the early Solar System.
Writing in the journal Science, they describe how aluminium radioisotopes can now offer precise timing of events 4.5 billion years ago.
The study shows that the rate of decay of isotopes can now be relied upon to give accurate measures of time for that period.
It is hoped that this will give new insights into how the Solar System formed in its first five million years.
The scientists showed how aluminium radioisotopes were uniformly distributed in the region where the Solar System was formed.
As the isotopes decayed steadily across the early Solar System, this allows their use as a type of clock for that period.
One of the scientists, Johan Villeneuve, told BBC News: "we can now use the isotopes to measure the age of different chondrules, parts of meteorites, and understand far more about the early part of our Solar System".
The findings could also shed light on the origins of the planets.
Philip Bland, from Imperial College London, described the research as "a really nice study".
"With their high precision measurements, they are able to date formation times for chondrules very precisely," he said.
"And what is interesting is that they've shown that these building blocks for asteroids, and possibly for planets as well, formed over an extended period of two to three million years."