A creature that can repair and regenerate limbs and organs is helping scientists at the University of Minnesota understand why humans can’t do the same. The critically endangered axolotl—also known as the Mexican salamander—shares a type of cell, called a glial cell, with humans. If an axolotl hurts its spinal cord, its glial cells go to work to repair the nerve damage and fix the injury. The same cells in humans work to form scar tissue, which prevents nerve pathways from regenerating. Researchers hope that grasping the underlying process of how axolotls can regrow their bits will one day help us regrow ours. —Lori Cuthbert
Here’s proof that ticks are truly prehistoric pests: When scientists found 99-million-year-old ticks entombed in Burmese amber, one (top left) was engorged with blood. Judging by a feather entangled with another of the arachnids (center), ticks may have preyed on feathered dinosaurs in the Cretaceous period. —Lori Cuthbert
Settling on Mars? That radiation is a killer. To block harmful cosmic rays while letting light in, the protective habitat depicted below would use ice.