The idea that cosmic dust triggers glaciation on Earth has been blown away.
It was previously thought that an excess of cosmic dust falling on Earth could encourage clouds to form, causing more sunlight to reflect back into space and tipping Earth into a glacial cycle.
Gisela Winckler from the Lamont-Doherty Earth Observatory in New York and her colleague have found that this is not the case. They measured levels of helium-3 (an isotope that is rare on Earth but abundant in space) in an Antarctic ice core going back nearly 30,000 years, and showed that levels of cosmic dust…
