Letters to the Editor Humans Letters from the July 14, 2007, issue of Science News By Science News July 8, 2007 at 5:51 pm - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print At least a few years to prepare “Northern Exposure: The inhospitable side of the galaxy?” (SN: 4/21/07, p. 244) posits that every 64 million years a mass die-off occurs due to increased cosmic rays. When will the cosmic rays again be at their maximum? Robert RichardsMetairie, La. The article failed to mention when the next cosmic-ray bath is due.