Nareen Melkonian
Apr 3, 2012

Argonne's superconducting ATLAS challenges current theory on early days of our solar system

According to research at the US Department of Energy’s Argonne National Lab, the early days of our solar system might be quite different than previously thought. The study used more sensitive instruments to find a different half-life for samarium, one of the isotopes used to chart the evolution of the solar system. Current theory states several billion years ago, everything in our solar system formed from stardust, some of which was formed in giant supernova explosions. One of these is the isotope samarium-146, which is unstable and occasionally emits a particle that changes the atom into a different element. Using the same technique as radiocarbon dating, scientists can calculate how long it’s been since the Sm-146 was created. By counting Sm-146 atoms with the Argonne Tandem Linac Accelerator System (ATLAS) and tracking the particles that the sample emits, the team came up with just 68 million years for its half-life -- significantly shorter than the previous value of 103 million years.