Tonight is Sep 03, 2010
Courtesy U.S. Naval Observatory
This morning, at 8 a.m. Universal Time, our planet Earth swings to its most distant point from the sun for this year.
Earth is 152 million kilometers from the sun today, 5 million kilometers farther away than in early January. Our world will be closest to the sun next on January 4 of 2009.
Even though Earth is farthest from the sun today, it’s still summer in the northern hemisphere. Right now, the sun climbs high into the northern hemisphere sky but stays low in the sky visible from the southern hemisphere. The solstice on June 20 ushered summer into the northern hemisphere and winter into the southern.
So our distance from the sun doesn’t cause the seasons. But it does affect the length of each season. Earth is now traveling most slowly in its orbit. Earth takes nearly 94 days to travel a quarter-orbit from the June solstice to the September equinox.
In January, when Earth sweeps closest to the sun, our planet travels most swiftly for the year, and takes five fewer days to swing from the December solstice to the March equinox.
And that means – because we’re farthest from the sun in July, the northern hemisphere’s longest season is summer – while the southern hemisphere’s longest season is winter.
Length of the seasons in 2008:
March equinox to June solstice: 92 days 18 hours 11 minutes
June solstice to September equinox: 93 days 15 hours 45 minutes
September equinox to December solstice: 89 days 20 hours 20 minutes
December solstice to March equinox (2009): 88 days 23 hours 40 minutes
