Peanut butter's thick, sticky spread is not a solid, but a liquid. Explore the many curious properties of fluid materials that can be tricky to grasp.
This week, we say goodbye to the rover that turned a 90-day mission into a 14-year journey on the Red Planet.
Arizona, and seven other states that use the Colorado River for water, is putting together a plan to address future drought and water needs.
A new review suggests the world's insects are facing catastrophic declines, which could ricochet through food chains—but entomologists say there are still uncertainties.
President Trump said he wants to end the spread of HIV in the U.S. by 2030. But he stayed silent on climate change.