Summer Solstice 2013

Today is the June Solstice, the first day of summer in the northern hemisphere. The new season officially began at 5:04 UTC, which is 1:04 Eastern Daylight Time.

Astronomical seasons are the result of the tilt of the Earth’s axis, a 23.5° angle. Today, as summer begins, the northern half of our planet is slanted toward the sun.  This position allows the northern hemisphere to receive the sun’s energy at a more direct angle, warming the entire region.

The summer solstice is often called the “longest day of the year”.  This, however, is a bit of a misnomer as one day always contains twenty-four hours.  Nonetheless, today is the day with the longest duration of daylight. Since the winter solstice in December, the sun – in its apparent seasonal journey across the sky – has been making its way north. Reaching its northern-most position at the Tropic of Cancer today, it stopped.  This phenomenon is where today’s event takes its name. Solstice is a word derived from Latin meaning, “sun stands still”.

SeasonsImage Credit: NASA