Kivu is no ordinary lake, with dense depths packed with methane and carbon dioxide gas. Its features hold aquatic puzzles, explosive hazards and the capacity to provide valuable energy.

Male-male competition, and sometimes female preferences, have driven arms races for the flashiest horns, antlers, pincers, tusks and claws

Several new missions aim squarely at a long-standing astronomical conundrum, with the promise of improving space-weather predictions

How limestone-covered algae sway global climate — and how their fate may shift as the oceans acidify

Technology is enabling increasingly lifelike models of organs to help doctors practice operations.

Our brains manage to construct stable images even as our eyes keep darting around. Here’s what we know about how that happens. 

The eight-legged weavers have been hunting insects for almost 400 years, flaunting their long history in a rich array of architectures. Scientists are still figuring out the taxonomy of them all.