Maine The post How can the visible universe be 46 billion light-years in radius when the universe is only 13.8 billion years old? appeared first on Astronomy Magazine.

We learn about the planets, stars, and galaxies by their light—visible light ... but detectable by certain telescopes on Earth and in space—and by the still longer waves of radio energy ...

The colorful northern lights may reveal themselves to a wide swath of Americans Friday night due to an impending solar storm ...

Another display of the northern lights could be visible this weekend in several U.S. states following a severe solar storm.