We’ve celebrated Winter Solstice. The religious holidays have been commemorated. Tonight we get to tear 2010 off the calendar and start fresh! But we still won’t be quite done celebrating. There is one more celestial event to honor.
I just learned about this from an article a few days ago in the NYT.
If it’s the small things in life that matter, then the perihelion should. It happens because earth’s orbit around the sun is an ellipsis instead of a perfect circle. At the perihelion, we are as close as we get to the sun by a small matter of 3 million miles.
We are closer by 3-1/2 percent on January 3 than we will be on July 3. That makes the sunlight 7 percent stronger in mid-winter than mid-summer. We are also moving faster. Watch us whirl on this cool model brought to us by The National Earth Science Teachers Assn.
The irregularity of the perihelion does not create our seasons. That is caused by the 23.5-degree tilt of Earth’s spin axis.
We are lucky that we don’t notice perihelion. The effect is so small because Earth’s orbit is pretty darn close to true. Other planets with orbits more extreme feel their perihelions much more. Pluto has the wildest orbit – so wild that at its farthest out, its atmosphere freezes and falls to the ground.
But I think we should still observe our perihelion. It’s part of understanding what and where we are and keeping a little humility and perspective.
This year it will be next Monday, Jan 3. Take a moment Monday to think about that fiery ball that we owe everything to.
Our slightly wobbly relationship to the sun pushes the date of perihelion slowly through our calendar year. It is progressing toward Spring about one day each 57 years.
Perihelion is now a day later than when we set off the first A Bomb, a week later than when Johannes Kepler, with his careful calculations, revealed the elliptical orbit of our Earth, and a year later than when early humans crossed the Bering Straits into Alaska.
Happy New Year &
Pleasant Perihelion to you!
Categories: Climate Change