Orcas’ physiology should hamper their ability to catch whale sharks. “They have lungs,” says Pancaldi. The whale shark, with gills, can do infinite lurks and dive 2,000 meters deep, while its mammal ...

In the new study, researchers compared digital 3-D models of ancient hominid footprints and trackways to those made by people today — including Kenyan herders who rarely or never wear shoes — ...

In How to Kill an Asteroid, Robin George Andrews looks at the successes and shortcomings of planetary defense.