We measure the extremely long distances between things in space by light years. A light year is the distance that light travels in one Earth year. Light travels at about 300,000 kilometres per second.

Planetariums were a hit with the public. Within decades, they had spread around the world – the first planetarium in the United States opened in Chicago in 1930, while the first one in Asia opened in ...

But cutting the residential solar credit will happen sooner. Companies have announced more than $20 billion in clean-energy investments in North Carolina in recent years.

Astronomers are monitoring an object headed our way that may have wandered over from another star system. The European Space Agency said Wednesday that scientists have discovered what might be ...

In several Goma neighborhoods where almost nobody had electricity just five years ago, a small solar network is offering a flicker of hope despite widespread poverty and the city’s violent ...