The meteor fragments returned by OSIRIS-REx shed light on the entwined history of water and the chemical ingredients of life in the solar system.

Science dioramas of yesteryear can highlight the biases of the time. Exhibit experts are reimagining, annotating — and sometimes mothballing — the scenes.

Rivers began pumping weathered material into the sea about a billion years after Earth formed, suggesting continents may have gotten an early start.

Certain metallic rocks seem to be making oxygen in the dark, without light or sunshine, at the bottom of the ocean.