For a long stretch of Earth’s history, our planet might have looked green from a distance, instead of the pale blue dot we know today. Earth’s green period, which lasted from around 3 billion ...

Why Trust Us? A new study from scientists at Nagoya University in Japan analyzes how the Earth likely sported a green hue in its early days. Due to evolutionary pressures and the light spectrum ...

The green-tinged Comet Nishimura is zipping past Earth, and you have a few days to grab what could be a one-time-only chance to spot it — with a little know-how. Comet Nishimura, named after the ...