Improvements in samarium detection could tell us more about how the solar system formed.

A team of Indian and German scientists have developed a method for detecting tiny amounts of samarium-146, a radioisotope produced in supernovae. Cosmologists believe that our solar system was formed from the remains of one or more supernovae, said team member Gunther Korschinek from the Technical University of Munich, Germany. Because samarium-146 has a half-life of 100 million years, it is one of the few radioisotopes still left from the formation of the solar system. 

By measuring the amount of samarium-146 in the earth's crust, the team hope to find out more about supernovae and about the conditions in which the solar system was formed. Their main obstacles are the minuscule amounts of samarium-146 left to measure, and a much larger amount of an isotope with the same mass, neodymium-146, which overwhelms the samarium signal. 'Neodymium-146 is expected to be at least a million times more abundant than the vanishing amounts of samarium-146,' said Korschinek. 

To overcome this problem, the team developed a liquid-liquid extraction method which can separate out the samarium from the neodymium. The amount of samarium-146 can then be measured by accelerator mass spectrometry. The technique 'gives us a handle for the first time to look for samarium-146 in natural samples ... and look back in time to before our solar system was formed,' said Korschinek.

Clare Boothby