Top image photographed in 2012
Bottom image photographed in 1962
Although people have observed clouds for tens of thousands of years, one group of clouds long escaped human detection. Not because those clouds were too small to see, but because they were too big. The dawn of the satellite era changed that, revealing a type of cloud that scientists named “actinoform.” The name of these radial, or leaf-shaped, clouds is based on the Greek term for “ray.”
