# has ever been used this method to claculate suns distance?

• July 28th, 2009, 01:17 PM
luxtpm
has ever been used this method to claculate suns distance?
it has to be a day of half moon like today

this means if the sun is an a very big distance distance sun and moon will be 90º apart

now in the day of half moon you measure the angle between both and voila you know how much farther is the sun than the moon

i just did it today i saw the sun and the moon and measure the angle aiming to both with both arms

to my surprise it turn out the had an agle of aproximatly 70º, certainly very far from 90º

can somebody explain this?

if the angle is 70º it means the sun is 3 times farther than the moon

:shock:http://i40.photobucket.com/albums/e2...undistance.jpg
• July 28th, 2009, 02:09 PM
Dishmaster
How high above the horizon were sun and moon? Have you considered atmospheric refraction?

How accurately can you confirm that the phase was half moon at that time?

http://stardate.org/nightsky/almanac/

Remember that the moon moves about 12 degrees per day around the earth. So, if you are half a day off, your estimate is already quite inaccurate.
• July 28th, 2009, 02:21 PM
luxtpm
it was 2 hours after half moon

at 5 o clock noticed this

edit:

notice half moon is exactly today:

http://stardate.org/nightsky/moon/

here:

http://www.astro.washington.edu/cour...nes/rung3.html

now why did i get 70º?
• July 28th, 2009, 03:06 PM
Arcane_Mathematician
Atmospheric refraction is a biggie, along with the dirrection from half moon it was traveling, whether it was moving towards the sun or away, in terms of your perspective.
• July 28th, 2009, 04:07 PM
luxtpm
oh never mind i suppose calculating angles by eye is not valid and i already got my answer, its valid use moon shadows to calculate suns distance