Thursday is the first day of spring, or the vernal equinox, in the Northern Hemisphere. During an equinox, the center of the sun is on the same plane as the equator. After the vernal equinox in March, ...

While sunsets on Mars are uniquely moody, NASA 's Curiosity rover has captured a stunning image of a martian sunset, featuring light rays that illuminated a bank of clouds as the sun set over the ...