Every year around March 20, the sun aligns with the Earth"s equator, and day and night are about equal in length. In the Northern Hemisphere, this is called the spring or vernal equinox, and it marks the astronomical exit of winter into the brighter, warmer springtime. From now on, we can enjoy days that are longer than nights. And a sharp eye might spot a flowering crocus, like the ones in today"s image, among the first flowers to bloom every year.