The avocados on the right are Hass, America's favorite variety of the green fruit. At left are GEM avocados, the great-granddaughter of the Hass. GEM avocados grow well in California's Central Valley and, in taste tests, they scored better than the Hass in terms of eating quality.
Ezra David Romero/Valley Public Radio
The elaborate Alnwick Garden in northeast England includes a "Poison Garden" that showcases plants with killer properties. Visitors are invited to look but not touch or even smell.
Joanne Silberner for NPR
An image taken on July 19, 2013, by the wide-angle camera on NASA's Cassini spacecraft captured Saturn, its rings and planet Earth, which is the tiny dot in the lower right.
NASA/JPL-Caltech/Space Science Institute
Scientists placed two clusters of cultured forebrain cells side by side (each cluster the size of a head of a pin). Within days, the "minibrains" had fused and particular neurons (in green) migrated from the left side to the right side, as subsets of cells do in a real brain.
Courtesy of Pasca lab/Stanford University
(Left) A close-up view of a spirally fractured mastodon femur. (Right) A boulder discovered at the Cerutti Mastodon site in San Diego County thought to have been used by early humans as a hammerstone.
Tom Démeré/San Diego Natural History Museum