In the past two years, without much notice, solar power has begun to truly transform the world’s energy system.

The sun is Earth's closest star, yet its beauty is too intense to appreciate with the naked eye. Here are some of the most stunning solar images that our satellites and telescopes have captured.

What color is moonlight typically, and what other colors can moonlight look like from our perspective on Earth?

Even if Earth does survive, it won’t be pretty. The temperature of our planet will be about 1,300 degrees C, hot enough to ...