Our celestial origins

Life on earth may have benefited from the explosion of massive stars, according to Danish physicist Henrik Svensmark of the Technical University of Denmark.
When massive stars reach the end of their lives they explode as supernovae and in the process release vast amounts high-energy charged particles known as galactic cosmic rays (GCR). If a supernova is close enough to earth these GCR may reach and have a direct impact on the atmosphere of the Earth.
Dr. Svensmark conducted analyses that looked back through 500 million years of geological and astronomical data to determine the rate at which these explosions occurred and whether they were related to life on earth. He focused his attention on animals with the best fossil record, so that their fate across time could be determined. This included Invertebrate animals, such as shrimps, octopuses, the extinct trilobites and ammonites. His findings show that the last 500 million years seem very well explained by both tectonics affecting the sea-level and variations in supernova rate.
"The biosphere seems to contain a reflection of the sky, in that the evolution of life mirrors the evolution of the Galaxy." said Dr. Svensmark in a statement to the press.

Article DOI:
10.1111/j.1365-2966.2012.20953.x