The Earth’s axis is inclined at a fixed angle of 23.5 degrees from perpendicular to the orbital plane. This results in annual changes in the height of the Sun above the horizon and is the cause of the change of seasons. In 2007, the Winter Solstice will occur on December 22, at 1:08 AM EST. The Sun will reach it’s southern-most point of the sky. This will result in the day with the shortest period of sunlight. Early humans who observed this phenomena celebrated the winter solstice as a time of renewal and rebirth because after this date, the days would slowly become longer.
Perihelion will occur on January 2, 2008 at about 7:00 PM EST. This is the time when the Earth is closest to the Sun in it’s elliptical orbit. Early humans had no way of observing this, so there are no primitive holidays associated with it. It’s proximity to the Gregorian New Year is purely coincidental.
We hope that you enjoy these celestial occasions as much as we do.
Have a Merry Winter Solstice and a Happy Perihelion!