Europa Clipper: NASA Investigates an Icy Ocean

Europa, one of Jupiter’s four biggest moons, appears to harbor a liquid ocean not far beneath its bright, icy surface. Is there life there? NASA plans to fly the Europa Clipper spacecraft to orbit Jupiter and, making frequent flybys of Europa, will study the...

Astronomy Fundamentals: The Last Trillionth of the Journey

As stargazers, we look out across space at objects floating in what is mostly vast emptiness. The light we see travels at its breathtaking speed through a vacuum, only now and then perhaps encountering some wisps of gases and dusts. To an observer on our Moon, or to...