The 2010 Summer Solstice

It's about time for the Summer Solstice for the year AD 2010.  So, what exactly is a solstice.

Simply put, it's the time when we're farthest away from the Sun.  First: the complex definition.

Now, everybody knows that planets orbit around something much bigger, like a star.  Orbits, in this case, can be assumed to be circular (even though every astronomer will tell you that they're "elliptical"), thus they don't really contribute to our seasons.  Our Earth has an axial tilt of about 23.44 degrees (the tropics are at 23.44 degrees N and S).  Again, that's not hugely important, although it is what causes the important part.  Now here's why we have seasons: because of the atmosphere having a larger angle to the sun, more energy gets reflected into space because of atmospheric diffusion. Likewise, when the sun is higher in the sky (summer in the Northern hemisphere), the sun would have less atmosphere to go through and, thus, less atmospheric diffusion.

What?!  Here's the simpler definition: basically, we're flying through space at about 67,000 miles an hour relative to the sun.  In about 15,000 miles, the South Pole will be as far away from the Sun as it has been and will be this year.

Wikipedia has a great article on solstices.

Ok, I'm done :-)