Applause erupted at NASA's New Horizons control center in the wake of the eponymous spacecraft's flyby of Pluto.
If life on earth is to survive then we must reorient the means by which we survive currently toward keeping a balance with nature.
The Pope calls for serious and immediate action to address climate change and other environmental crises.
It's among the universe's first generation of galaxies, from 13.1 billion years ago.
We have entered a new geological era, in which human action is changing the physical world around us.
As California struggles to meet new water use restrictions, the governor is urging a sharp increase in fines for the worst violators.
It was a picture perfect Sunday for a peaceful march against the most violent instruments of war: nuclear weapons.
The first Arbor Day in the world was celebrated in the small Spanish village of Villanueva de la Sierra in 1805.
Scientists have linked a swarm of small earthquakes west of Fort Worth, Texas, to nearby natural gas wells and wastewater injection.
On Earth Day 2015, humanity faces increasing environmental dangers, but movements to solve the issues are growing.