Expert: Jayendra Upadhye - 1/5/2005

Question
what is the distance between the sun and the earth during a vernal equinox or summer solstice?
site reference required

Answer
Hi thq,
You have Yahoo search to thank for this!
I tried Google, but could not hit "pay dirt" soon enough!

The site :-
http://64.233.187.104/search?q=cache:I2WdvfDxMScJ:www.krm.se/dok/Exam-March-2004...
lists on its page 3, precise distances as under:
1.016 AU Summer Solstice
0.984 AU Winter Solstice
0.996 AU Vernal Equinox
1.0034 AU Autumnal Equinox

This html page (site) :-
http://www.powerfromthesun.net/chapter3/Chapter3Word.htm
lists it all with diagrams!
the answer is (courtesy the same site of course)..
1 - the distances at both equinoxes is close to 1 AU or 1.495*10^11 met.
The autumnal equinox occurs on september 23 (day 266) and on oct 5 we are exactly 1 AU away.
The vernal equinox occurs on march 20 (day 79) and on April 3 we are 1 AU away.

This other site gives the earth sun distance variation by months.
Month   Average Earth-Sun Distance
------  --------------------------
January   147 000 000 Km
March     149 000 000 Km
June      153 000 000 Km
July      153 000 000 Km
September 150 000 000 Km
December  148 000 000 Km


But a surprisingly high number of sites simply shy away from mentioning the actual figures after coming tantalisingly (and frustratingly) close to it!

Wonder why all those people thought these distances as so unimportant!
Jayen