Monday, September 17, 2007

Every eight years

My predawn commute has recently been guided by a bright beacon rising in the East: the planet Venus in its "Morning Star" guise.

Venus is a planet, of course, not a star. Its bright appearance - exceptionally bright right now, as it was in its evening apparition earlier this year - is caused by sunlight reflecting off of sulfuric acid clouds in Venus's upper atmosphere. Venus only appears in the Eastern sky in the morning or the Western sky in the evening because it is an "inferior" planet, closer to the Sun than we are, so bound to appear in the vicinity of the Sun. ("Superior" planets can appear far from the sun in the sky, because - well, you can work it out for yourselves. Copernicus did.) Unfortunately, some people persist in calling Venus "The North Star", which is wrong in every way it's possible to be wrong. Heaven help them if they try to us Venus to find their way North.

The orbital period of Venus is related to the orbital period of Earth in such a way that Venus appears at the same place in our sky every eight years. Watching Venus this Spring and Summer brought back memories of the Spring and Summer of 1999 and many happy trips to visit some newlywed friends who were living in an apartment in Jim Thorpe and building a house in the nearby woods. In September of 1999 I believe I was just winding down my morning dogwalks with Haley, walks that would not resume until the Summer of 2004, and we often walked under the arc-welder brightness of Venus in its morning appearance.

If you were lucky enough to have noticed Venus during this current apparition, one in which it has shined as brightly and risen as high as it ever does in its eight-year cycle, try to remember where you were and what you were doing and who you were with and who you were. In 2015, when the orbital ballet of Earth and Venus brings Venus into another spectacular appearance, perhaps you will look upon its beautiful brightness and remember what things were like back in 2007.


whimsicalnbrainpan said...

I missed it. I guess there is always 2015.

Super G said...

I had been appreciated how incredibly bright Venus has been the last few days.

Whimsical Brain - you only need go out at about 5:30 or so and look east to appreciate the beauty (at least the skies are very clear in NC these days).