PDA

View Full Version : bye bye moon?



comradebillyboy
2005-Dec-30, 01:31 AM
why is the moon moving away from the earth? will it ever completly escape earth orbit?

tony873004
2005-Dec-30, 02:11 AM
It pulls a tide on the Earth. Earth's rotation advanced the buldge slightly ahead of the Moon. The buldge pulls on the Moon and speeds it up. The Moon responds by climbing into a higher orbit. The Earth responds by slowing its rotation.

As the Moon gets farther, the tide it pulls gets smaller, so the rate at which it receeds slows. Eventually, the Earth's rotation will match the Moon's orbital period. At that point, the Moon will receed no more.

The Sun will ultimately swell up into a red giant, probably destroying the Earth in the process. This will likely happen before the Earth becomes tidally locked to the Moon.

comradebillyboy
2005-Dec-30, 05:36 AM
thanks for the info

jkmccrann
2006-Jan-08, 01:24 PM
I don't think the surfing community would enjoy a tidally locked moon very much, so its probably a good thing its not likely to happen before the sun blows up. ;)

mickal555
2006-Jan-08, 01:25 PM
We'd still get waves though wouln't we?

jkmccrann
2006-Jan-08, 01:27 PM
I suppose, either way, I'm not a surfer, more a snowboarder, so I'm not too worried. hehehe

mickal555
2006-Jan-08, 01:29 PM
Sun explodes = no snow ;)

jkmccrann
2006-Jan-08, 01:45 PM
Good point, I"ll have to make sure I get over to the European Alps before that tragedy. The so-called `Victorian Alps' are pretty average in comparison.

Cheers for the heads-up buddy.

the_shaggy_one
2006-Jan-09, 01:45 AM
If the earth lasts long enough to get tidally locked with the moon, the tides the sun causes on the earth will eventually slow the earth down, which will pull the moon in the opposite direction, bringing it closer to earth again. I think in 30 billion years or so, the moon passes within the Roche limit, and breaks up/crashes into the earth.

Whee!

Titana
2006-Jan-09, 02:03 AM
The Sun will ultimately swell up into a red giant, probably destroying the Earth in the process. This will likely happen before the Earth becomes tidally locked to the Moon.


Yes, it will likely happen before Earth becomes tidally locked to the Moon.


It is expected that in 15 billion years, the orbit will stabilize at 1.6 times its present size, and the Earth day will be 55 days long equal to the time it will take the Moon to orbit the Earth. Of course, in less than 7 billion years, the Sun will have evolved into a red giant star and engulfed the Earth-Moon system, thereby incinerating it!

http://www.astronomycafe.net/qadir/q1282.html


Titana.

Kaptain K
2006-Jan-11, 12:38 AM
It is still open to debate as to whether the Earth will be swallowed up by the expanding Sun. Mercury and Venus are definite goners. Mars definitely escapes. The Earth is on the border line.

astromark
2006-Jan-11, 06:57 AM
Yes.,. . The planet may well servive, but not our atmosphear or oceans. Lets hope we've moved on a...