A beautiful green aurora borealis streaked through the night sky, over a snow-covered forest in Fairbanks, Alaska, on Tuesday ...

Botanists have found a stand of rare trees in Tanzania’s Zanzibar archipelago not known to grow wild anywhere else in Africa.

The Sahara Desert wasn’t always a barren wasteland—evidence suggests it was once home to lush vegetation, rivers, and thriving wildlife. Scientists are uncovering traces of this lost ecosystem, ...