jupiter as big as the moon.

Have any of you guys heard about Jupiter being as big as the moon? i heard it was supposed to happen i cant remember if its this month or sometime this year. Any body hear this

that's extremely impossible. no optical illusion is going to make it appear that big and it would have to severely deviate from its orbit to come close enough for that. if that happened you would definitely have other things to worry about.

If from our point of view the moon and the sun appear roughly the same size you could divide the suns diameter with the moons. (sun 1.4 million kn / moon 3,474 km = 403 (ish)

Do the same with Jupiter and you get (1.4 mill / 142,800 km = 9.8 (ish)

That would put Jupiter apx 10 times further away from earth as the moon (384400 x 10 = 3,844,000 km) where as it is normally 588,000,000 km

588,000,000 / 3,844,000 = 153 (ish)

That's one serious deviation (although I have a feeling I've gone wrong somewhere!)

Any who, bad day for the solar system whatever

It's a twist on the old ""Mars will be as big as the moon"" email.

I've received that email several times in the last couple of years, with just about every planet listed at one point or another.

It is not Jupiter that was supposed to be the size of the moon, but the planet Mars. In any case, neither Jupiter or Mars would even come close to approaching the size of the moon.

Since the planets rotate around the Sun in varying orbits, it is factual that Earth is approaching, and will soon overtake, Mars, but even at its closest distance, Earth and Mars will still be 55,000,000 miles apart.

To get an idea of the relative sizes of the Moon and Mars in this context:

Using the diameter of the Moon (2160 miles) as an example, extend your arm towards the Moon, then exactly 18 inches from your eye, accurately place the image of the Moon between your thumb and forefinger. Then, carefully measure the space between them, you will find a space of .162 inches. (A BB pellet held between thumb and finger measures .177 inches)

On the other hand, using the diameter of Mars (4219 miles) and going through the same finger exercise, you'd find that the space now between finger and thumb is only .0014 inches. Obviously this something you can't measure, but it is something that can be proven to be a mathematical fact.

Therefore, because of the large disparity of diameter sizes, Mars won't even come close to appearing to be the size of the moon and, in fact, one could line up, side by side, 115 images of Mars aross the face of the Moon. Mars' small size and great distance from Earth is such that one, usually, sees only the reflection of the Sun off of Mars and not the planet itself

Put another way, if you placed a regular sized golf ball (1.68" D.) at a distance of 609 yards from where you're standing, the view you would see of the golf ball, if you could see it at all at that distance, would be the actual size that Mars would appear to be in the sky, if you could observe it unhindered by the atmosphere.