Topic: =/\= earth may have had two moons! (Read 4269 times)

stoneyface · « **on:** August 03, 2011, 05:08:49 pm »

in a strange story, it was revealed that the earth may have had two moons in it's past. the theory goes that the second moon (only 750m across) crashed into the far side of the moon at one point. this crash may account for the much different topography of the far side of the moon as compared to the visible side. read the story here: http://www.space.com/12529-earth-2-moons-collision-moon-formation.html

EschelonOfJudgemnt · « **Reply #1 on:** August 03, 2011, 07:58:53 pm »

Interesting hypothesis!

I'm guessing the Chinese will be the ones who will send the next manned mission to investigate this, what with all the cost cutting going on lately...

Kreeargh · « **Reply #2 on:** August 03, 2011, 10:40:47 pm »

There was a release of info about a rouge astroid in earths orbit. Makes one wonder if its the truth or what. It looks like as some say a rouge object hit the planet to end things. I wonder now if its goan hit agian and they dont see that.

Grand Master of Shadows NCC37385 · « **Reply #3 on:** August 04, 2011, 08:05:50 am »

Im the spelling police. Pull this thread over.

Rogue= uncontrolled, unpredictable. Rouge= red, red cosmetic.

stoneyface · « **Reply #4 on:** August 04, 2011, 07:01:07 pm »

the asteroid in question is the "trojan" asteroid located in the l4 lagrange point and is only 300 meters across. this would have been a "trojan moon" that was small and in front of or behind the moon in orbit. something affected it's orbit and caused it to crash into the moon. interesting and explains a lot of things

FoaS_XC · « **Reply #5 on:** August 04, 2011, 09:23:44 pm »

I'm not an astrophycisist. I can't say for certain, but faster orbit of this "Trojan moon" despite it being the same distance from Earth as Luna sounds odd to me. Doesn't it violate Kepler's third law? I think I'm missing something there, though.

Also: wouldn't an impact like that mess with the rotational aspect of Luna? it is tidally locked to Earth after all?

not trying to poke holes or anything, I'd just love to see more data concerning these two things, or corrections there in.

marstone · « **Reply #6 on:** August 04, 2011, 09:31:51 pm »

from what I heard on the theory of this second moon, is their actually could have been more then one extra, but the others would have spun off. As for distance and speed out it could have been on one of the other langual (sic) points, they are not as stable.

From the guy I listened to on the moon being hit by this other smaller moon, it was a really slow speed impact (for space that is). About twice the speed of a bullet. The simulations of the impact showed it could have wabbbled the orbit of the moon, alittle. Or might even have put alittle spin on the moon when it hit, that slowed and quit naturally. now that slight rotation could be why the impact is on the far side of the moon, it could have happened on what would have been the side, imparted alittle spin, and made the impact look like it was on the far side.

Personally I am not so sure about this theory, but it was worked out. It is also based on the huge impact theory of creation of our moon.

FCM_SFHQ_XC · « **Reply #7 on:** August 04, 2011, 11:02:55 pm »

Quote from: FoaS_XC on August 04, 2011, 09:23:44 pm

I'm not an astrophycisist. I can't say for certain, but faster orbit of this "Trojan moon" despite it being the same distance from Earth as Luna sounds odd to me. Doesn't it violate Kepler's third law? I think I'm missing something there, though.

Also: wouldn't an impact like that mess with the rotational aspect of Luna? it is tidally locked to Earth after all?

not quite, from laser measurements of the moons distance there is an ever so slightly growing distance between the moon and earth so it'll take a LONG time but in a few million/billion years the moon might just break orbit with earth, but by then we'll be able to build moons from plasma I'm sure lol (maybe not quite but you get my point)
I dunno the latest on this data as it was several years ago when I saw this show up in the various tech/space articles and havent really kept up with it.

FoaS_XC · « **Reply #8 on:** August 04, 2011, 11:19:14 pm »

Well, my point was if the "Trojan Moon" was chasing Luna in the same orbit, then the major axis of the orbit of both moons should be the same amount. by Kepler's third law the angular velocity of both moons should be the same. So how could the Trojan Moon chase Luna down - they are going the same speed.... But I think Marstone answered.

marstone · « **Reply #9 on:** August 05, 2011, 01:14:36 am »

Quote from: FoaS_XC on August 04, 2011, 11:19:14 pm

Well, my point was if the "Trojan Moon" was chasing Luna in the same orbit, then the major axis of the orbit of both moons should be the same amount. by Kepler's third law the angular velocity of both moons should be the same. So how could the Trojan Moon chase Luna down - they are going the same speed.... But I think Marstone answered.

Now since the second moon was suppose to be about 1/20th the mass of the moon, wouldn't it's orbit speed have to be different because of the mass? Unless it was in one of the locked positions based on the gravity of the earth and moon together. Thus once it lost it's balance on an unstable point, it would "crash" into the moon.

Or if it wasn't in a locked position. It's speed could have been influenced by the gravity of the moon and was "tugged" alittle faster then it should have been so it would slowly catch up, getting alittle faster as it got closer.

Kreeargh · « **Reply #10 on:** August 05, 2011, 02:11:12 am »

Quote from: Grand Master of Shadows NCC37385 on August 04, 2011, 08:05:50 am

Im the spelling police. Pull this thread over.

Rogue= uncontrolled, unpredictable. Rouge= red, red cosmetic.

Well someone got rid of the spell check sorry I am not as smart as the rest of you all . Infact spelling is the LAST thing i care about . I quoted another theory on how things may have become. If anything is a fact it will come out but for now I

stoneyface · « **Reply #11 on:** August 05, 2011, 06:02:28 pm »

well i will try to help explain this. i have done some more reading on this and there has always been a major collision in the moon's history. we have known about it for a long time. one huge collision was just big enough to shatter the moon but not big enough to over come the moons gravity and it came back together again. that is why it is very un-uniform in make up. now scientist don't know if this collision was the outside influence on the moon and the trojan moon that caused the trojan to crash into the moon. (this is where research is now focusing in some areas)

the trojan moon and the regular moon were in the same orbital path and while you are correct that the trojan slamming into the moon on it's own would violate that law of angular momentum. but! in this case there was an outside influence that disturbed the orbits. and an outside influence means no violation of angular momentum. that outside influence could have been a rogue asteroid, comet, etc.

so, outside influence disturbs the orbits, smaller trojan moon slams into the current moon and obliterates itself.

MyJuliet · « **Reply #12 on:** August 18, 2011, 09:56:10 pm »

It will take a long time, but in the millions / billions of years the moon orbits the earth may just break through, but then we will be able to build from the plasma of the moon, I'm sure, LOL (maybe not, but you let me point) I do not know the data..
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