Passing through a giant molecular cloud: “Snowball” glaciations produced by interstellar dust
Article first published online: 4 FEB 2005
Copyright 2005 by the American Geophysical Union.
Geophysical Research Letters
Volume 32, Issue 3, February 2005
How to Cite
2005), Passing through a giant molecular cloud: “Snowball” glaciations produced by interstellar dust, Geophys. Res. Lett., 32, L03705, doi:10.1029/2004GL021890., , , , and (
- Issue published online: 4 FEB 2005
- Article first published online: 4 FEB 2005
- Manuscript Accepted: 5 JAN 2005
- Manuscript Revised: 21 DEC 2004
- Manuscript Received: 1 NOV 2004
 In its motion through the Milky Way galaxy, the solar system encounters an average -density (≥330 H atoms cm−3) giant molecular cloud (GMC) approximately every 108 years, a dense (∼2 × 103 H atoms cm−3) GMC every ∼109 years and will inevitably encounter them in the future [Talbot and Newman, 1977]. However, there have been no studies linking such events with severe (snowball) glaciations in Earth history. Here we show that dramatic climate change can be caused by interstellar dust accumulating in Earth's atmosphere during the solar system's immersion into a dense (∼2 × 103 H atoms cm−3) GMC. The stratospheric dust layer from such interstellar particles could provide enough radiative forcing to trigger the runaway ice-albedo feedback that results in global snowball glaciations. We also demonstrate that more frequent collisions with less dense GMCs could cause moderate ice ages.