When you say in 1 year the Earth travels 360 degrees around the Sun, you must mean the SIDEREAL year (365.256 days)! You say each day the Earth moves (revolves) 1.0146 degrees around the Sun, but how can this be when there are more days in a year than degrees in a circle? Dividing 365.256 by 360 = 1.0146, but shouldn’t you be dividing 360 by 365.256?

Thank you!
Bruce McClure

1 year has 23.9344696 hours per sidereal day * 366.242199 sidereal days per year

or

1 year has 24 hours per day * 365.242199 days

In 1 year the Earth travels 360 degrees around the Sun. Each day the Earth moves 1.0146 degrees and the stars appear to move 1.0146 degrees from 1 midnight to the next.

And is it a bigger difference on a leap year?

At the end of a long day, my wife Alice and I love to recline in our lawn chairs and to take in a sunset. Then we like to watch the brighter stars popping out into the twilight. Sometimes, we even fall asleep underneath the starry sky.

Since we observe from the same place daily, it’s quite obvious to us that when a star first comes out at dusk, it does so a bit westward of where it first appeared a day or two before. In fact, this is how Alice became aware of the disparity between the solar and sidereal days. In autumn, however, this disparity is not as obvious, because the sun sets a few minutes earlier with each passing day.

I enclose Jay Ryan’s comic strip “The Summer Triangle Effect” at http://www.mangobay.cc/users/moonfinder/sep-97.htm for any reader wanting to know more.

Bruce McClure

I suspect you’re right about people googling or going to Wikipedia to find out the meaning of “sidereal day.”

But how much more lovely to imagine oneself riding on a planet in space, with stars all around!

Deborah