|
Post by fireballs on Sept 2, 2010 16:33:42 GMT -4
Remember, fireballs - we're not measuring the angle or where the moon is in the sky - we're measuring its size. A very rough way to see how big one degree of the sky is - hold up you hand at arms length and stick up your little finger. Its width would be about 1 degree. Look at it like this - from directly overhead to the horizon is 90 0. So, the width of the moon is 1/180 of that. It moves across the sky at about 15 0 per hour. Let's say, you were facing North... The moon seems to be bigger than that when you look at it, doesn't it? But this is the size it would be when looking at the whole sky from the eastern horizon to the western horizon. I think the diagram illustrates just how small the Moon actually is in the sky. You need accurate instruments to send and receive signals to and from the moon. Could you (or someone) expand on this some more? I think I generally understand what you're saying, but I need some clarification. Specifically: "So, the width of the moon is 1/180 of that. It moves across the sky at about 15 0 per hour." This is the only part I'm lost on. Otherwise it all make sense
|
|
Al Johnston
"Cheer up!" they said, "It could be worse!" So I did, and it was.
Posts: 1,453
|
Post by Al Johnston on Sept 2, 2010 17:00:11 GMT -4
15o per hour is what you get when you divide 360o by 24 hours: the apparent motion of the Moon is due mostly to the daily rotation of the Earth
|
|
|
Post by fireballs on Sept 2, 2010 17:23:10 GMT -4
15 o per hour is what you get when you divide 360 o by 24 hours: the apparent motion of the Moon is due mostly to the daily rotation of the Earth Makes sense then
|
|
|
Post by Ginnie on Sept 2, 2010 17:28:34 GMT -4
Remember, fireballs - we're not measuring the angle or where the moon is in the sky - we're measuring its size. A very rough way to see how big one degree of the sky is - hold up you hand at arms length and stick up your little finger. Its width would be about 1 degree. Look at it like this - from directly overhead to the horizon is 90 0. So, the width of the moon is 1/180 of that. It moves across the sky at about 15 0 per hour. Let's say, you were facing North... The moon seems to be bigger than that when you look at it, doesn't it? But this is the size it would be when looking at the whole sky from the eastern horizon to the western horizon. I think the diagram illustrates just how small the Moon actually is in the sky. You need accurate instruments to send and receive signals to and from the moon. Could you (or someone) expand on this some more? I think I generally understand what you're saying, but I need some clarification. Specifically: "So, the width of the moon is 1/180 of that. It moves across the sky at about 15 0 per hour." This is the only part I'm lost on. Otherwise it all make sense Maybe this would be clearer:
|
|
|
Post by PhantomWolf on Sept 2, 2010 17:47:24 GMT -4
Our human senses like to play trick on us and we see things much bigger then they really are. Try taking a photo of the moon or a mountain without any zoom. When you view the image afterwards, you end up squinting and thinking, "is it really that small?"
|
|
|
Post by fireballs on Sept 2, 2010 20:36:21 GMT -4
|
|
|
Post by Ginnie on Sept 2, 2010 20:50:12 GMT -4
Well what'dya know... Seems like I actually did something right for a change! ;D Even the moon was in almost the same place. Hopefully, you can see the relative size of the moon in the sky. (And no, I was not aware of the other diagram's existence I swear. )
|
|