The Biosphere 2 facility, specifically its Landscape Evolution Observatory (LEO), serves as a research platform to investigate how life transforms landscapes, ranging from local environments to ...

In Arizona, nature is diverse and dramatic. The state's Tonto Natural Bridge State Park is home to the world's largest natural travertine bridge, where visitors can hike and explore its unparalleled ...

ORACLE, Ariz. — Plopped in the Sonoran Desert, just outside Tucson, Ariz., sits a massive, multilevel greenhouse that's probably best known as the inspiration for a Pauly Shore movie. A slick, stepped ...

The ocean's smallest engineers, calcifying plankton, quietly regulate Earth's thermostat by capturing and cycling carbon.

A rare encounter of two comets this week will have stargazers in awe after nearly a year of no easily seen comets.