Frank Hulley-Jones

• Space

A mysterious satellite known as Cosmos 2553 has raised concerns that Russia is conducting tests that could lead to a nuclear weapon in space.

• National

Cien años después de que tres hombres fueran asesinados a balazos, el relato difundido de generación en generación por sus descendientes contradice los registros oficiales. ¿Qué versión de la historia se recuerda?

• National

A century after three Tejano men were shot to death, the story descendants tell of their killing contradicts official accounts. Whose story counts as Texas history?

• Climate Solutions

An interactive step-by-step look at what happens when you let your lawn grow: flowering weeds bloom, feeding birds and bees.

• Environment

What one pine tree on an Arizona mountaintop can tell us about the hottest year on record -- and what lies ahead

• Climate

Coral reefs in the Seychelles off Africa may indicate where sea level rise will be felt the hardest as human-caused climate change impacts the world’s oceans.

• Science

The volcanic eruption in Tonga was one of the most powerful ever recorded. Experts say it was a wake-up call.

• Climate

Scientists journeyed to Greenland in an unprecedented experiment to drill for rocks beneath the ice sheet. But a crack in the ice threatened their mission — and their ability to predict the fate of the warming world.

Canada's Crawford Lake may hold evidence that humans have fundamentally changed Earth enough to have started the Anthropocene, a new chapter in geologic time.