Physicists call the dark energy that drives the universe “the cosmological constant.” Now the largest map of the cosmos to date hints that this mysterious energy has been changing over billions of years.

Climate change is increasing the number of days people are exposed to hazardous pollution, affecting already disadvantaged communities the most.

The far-traveled space probe is once again transmitting usable data, after a glitch caused months of gibberish.

In the first procedure of its kind, a 54-year-old New Jersey woman received a genetically engineered pig kidney and thymus after getting a heart pump.

Sales of vegan meat are trending downward in the US, with companies scrambling to win back customers.

Amsterdam is experimenting with roofs that not only grow plants but capture water for a building’s residents. Welcome to the squeezable sponge city of tomorrow.