More often than not, the aurora borealis (also known as the northern lights) appears as a pale streak of light almost indistinguishable ... to see another of nature’s wonders, the polar bear.

This holiday season, LumiNature, the Philadelphia Zoo's spectacular winter light show presented by PNC, is back with more ...

A celestial light show illuminates a distant spiral galaxy ... highlighting its brief nature. ESA also shared a slider tool ...