Celestia Forums

Well Have you ever seen the Moon as half the sky?
I was around 7 I went on to our balcony and I looked up and I saw the harvest moon look as half the sky. Is this just an illusion caused by our planet's atmosphere, or is the moon actually that close during the time of it's closest orbit (I forgot what that's called). Or is it both an illusion caused by our planet's atmosphere and caused by the moon actually being the closest it can get to earth?

-Shadow

Generally anything near the horizon looks smaller, because it's further away from us. The moon however looks just as large at the zenith. Because of this your brain thinks the moon is larger when it is close to the horizon. A similar illusion (but weaker, because one doesn't look directly at the sun as often) can be seen with a setting/rising sun.

Besides that, the moons orbit is somewhat excentric, but that accounts for no more than some 10% (just a guess, The computer I'm sitting behind at the moment doesn't have celestia, or any other astronomic software installed, and I'm too lazy to search for it on the internet). This accounts for the fact that some solar eclipses are annular, instead of total.

See the Celestia User's FAQ at the top of the User's Forum: Q7/A7

Thank's Selden i just read that.
But has anyone else ever seen anything similar?
A harvest moon that seems as half the sky?
Looks pretty cool IMO.

Sorry for asking, but when do you say that you saw the moon?? I'm asking for the date, 'cause now we have a beautiful new moon, so you just can't see it.

sometime in 1998 as i said I was 6 so I don't remember the exact date i just know sometime in 1998. There's rarely any clouds here about 40km east of Toronto.There's a nice 15-20 meter high hill about 200 m from my hose I go there sometimes there's a nice view of the sky.

I think memory plays the biggest part in this. I burned my hand as a kid on a parrafin burner about shoulder high - I saw the same thing again recently and it's lower than my knees , not how I remember it at all !

You should try measuring the apparent width of the moon when it looks small, and when it looks big, by holding up a pencil or something. The measurements are always much the same.

Umm this post is a little old by now...
I have a good memory, besides it was only 5 years ago I'm almost 12 now. So I'm positive that it looked as half the sky I have confimtion from my Dad who saw it too. The main Question in My First post was if it was just an illusion, or the moon was just at Perigee or both of those.

- Shadow

The moon being at perigee will not make any noticible difference. The moon will never take up half the sky. It's always subtends approximately 30 arc minutes. It does appear to be bigger near the horizon but that is just an illusion. It has nothing to do with the atmosphere. You should take measurements of the size of the moon at different times. A paper towel tube is good for just that thing. You will see that the moon always remains very close to the same size.

^^^----My post, forgot to log in. Doh!

Selden told me to go to the Celestia User FAQ The topic of the thread
changed after that.It Changed to; has anyone else ever seen anything similar? A harvest moon that seems as half the sky?

Anonymous wrote:The moon will never take up half the sky

Not completly half it was more like 20% of the sky.
When I'm tired,Hungry, or both I don't word my posts very well
it at that time also changes what I'm thinking to something else.
Sorry for sounding a little nasty


- Shadow

People see a lot of images of this huge moon everyone is talking about here (like the one in movies). That unfeasibly large moon can be produced using a telephoto lens as the moon is rising over a distant object (which in comparison will look small). Try it, i've done some lovely shots like that.

Pick a skyline, say a city that is miles off and wait for the moon to rise over it. As you zoom in on the objects, they both get larger by the same factor. Obviously, the moon appears the same size anywhere on the globe so hanging over a distant object it's going to dwarf it.

So... grab your camera and telephoto lens and go recreate that childhood image!!!

BTW - just downloaded and started to use Celestia - well impressed!

The moon will never take up half the sky. Perhaps what you saw was a UFO.

I increased the size of the moon by a factor of 100 by editing the solarsys.ssc file. It still didn't make to half the sky...