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.
Perihelion.
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.
..NASA image captured August 14-15, 2010 (photo credit: http://www.flickr.com/photos/gsfc/4923566097/)
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.
...Setting sun in the Sonoran Desert (photo credit: http://www.flickr.com/photos/tonythemisfit/4832671377/
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
Digging in the Driftless 
Happy New Year, Driftless, and thanks for mentioning Deft Home on your site. Looking forward to noting some thoughts about low-tech water supply.
Chris
And a Happy Perihelion to you, Denise. That’s even better it comes one day after the Packers beat the Bears. My chickens are happy and the world is looking good (if I ignore GCC, PO, soil loss, etc., etc. and the control of our country by Neandertals).
sigh
yes, the Neanderthal situation does make it hard to be cheerful. I try to stay upbeat because focusing on the negative saps my energy.
Think globally, act neighborly. That’s my mantra. Though the global thinking seems all fall in the gloomy category,
I have lots to keep me cheerful in the neighborhood department, and that includes my blog neighbors.
Denise
Dennis. Sorry to call you Denise. As you can well imagine, once I type Den … my fingers are on auto pilot.
If we are 3 million miles closer to the sun than in July, then will the sun’s gravitational pull make me weigh less? Every little bit helps.
I hadn’t thought of that. Long life Perihelion!
It’s so nice to know about this, especially since I was just able to read this today – the day of the Perihelion! It really should be celebrated! So, a very pleasant Perihelion Day to you, too!