I assume, of course, that "farest" is a typo and that you meant farthest? Anyway, one has nothing to do with the other - I think. I believe that it is just a coincidence that the solstice dates nearly coincide with the dates of perihelion and aphelion, but others who are more knowledgeable may know something I don't. Perihelion and aphelion are the points along the earth's orbit where the earth is closest and farthest from the sun, respectively. This is due, of course, to the earth's non-circular orbit. (Remember Kepler's laws.) The solstices are the dates on which the earth's tilt with respect to the sun is greatest. At the December solstice, the southern hemisphere sees more daylight (their summer) while at the June solstice the northern hemisphere sees more daylight. I believe that the difference in solar radiation that the earth receives from the sun varies by about 10 percent due to the earth's elliptical orbit. However, the sun angle accounts for a much greater difference in insolation between the hemispheres, and that difference controls our seasons. It would be interesting to speculate how the earth's climate would be different if perihelion occurred at or near the June solstice, instead of aphelion. Thoughts, anyone? Kim -----Original Message----- From: utah-astronomy-bounces+kimharch=cut.net@mailman.xmission.com [mailto:utah-astronomy-bounces+kimharch=cut.net@mailman.xmission.com] On Behalf Of baxman2@comcast.net Sent: Friday, July 06, 2007 12:19 PM To: utah-astronomy@mailman.xmission.com Subject: [Utah-astronomy] FW: Utah-Astronomy Digest, Vol 53, Issue 5 Why isn't the date of the summer solitice, and the date of the farest distance of Earth from the Sun, not the same? Internal Virus Database is out-of-date. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.9.6/865 - Release Date: 6/24/2007 8:33 AM