There's a supermassive black hole - 4 million times our sun's mass - in the center of our Milky Way galaxy. Astronomers who've measured star movements near this central black hole are now saying there might be a 2nd companion black hole near it.

The burning rainforest releases black carbon into the atmosphere, which, according to a growing number of scientific studies, directly contributes to the melting of glaciers.

White Island is one of several volcanoes in New Zealand that can produce sudden explosive eruptions at any time. An Earth scientist explains why.

We know of a couple of dozen so-called "stellar-mass" black holes in our Milky Way galaxy. They tend to be between about 5 and 20 times as heavy as our sun. This new black hole - in a distant spiral arm of the galaxy - is 70 times as heavy as the sun.

Masting is what biologists call the pattern of trees for miles around synchronizing to all produce lots of seeds – or very few. Why and how do they get on schedule?

... and it's poised to find thousands more. But will we find another Earth?

As temperatures drop, broad-leafed deciduous trees – think maples and oaks – withdraw the green chlorophyll from their leaves. Their leaves turn colors and fall. Evergreens solve the problem of winter in a different way.

This is the weekend we "fall back" here in the U.S. Are you glad? Sad? Mad? Advocates say daylight time saves energy and wins wars. Studies show injuries and illnesses rise when clocks change.

What kicked off a rapid cooling on Earth 12,800 years ago? Some geologists believe a fragmented comet or asteroid collided with Earth and caused the change. Read more from a scientist whose fieldwork at a South Carolina lake adds to the growing pile of evidence.

New research suggests that the tiny human species - that survived until about 18,000 years ago, later than any human species other than our own - evolved its small size remarkably quickly while living on an isolated island.