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Post by swamprat on Oct 15, 2012 17:55:53 GMT -6
Never Mind Life on Distant Planets. What About Distant Moons?
A new study — and a new book — herald a whole new chapter of exoplanet researchBy Jeffrey Kluger | October 15, 2012 Earthlings have never been terribly sophisticated cosmic tourists. Ask us which worlds we’d like most to visit and our answers are always the same: Mars! Jupiter! Saturn! Neptune! But there’s a shortsightedness in that — a little like going on a world tour and limiting your stops to London, Paris, Tokyo and New York. They’re fantastic places all, but as any global traveler will tell you, if you really want to learn a culture and grasp its richness, you’ve got to visit the provinces. The moons are our solar system’s provinces, and there are loads of them — up to 176 (depending on formal classification) circling six planets. Some are little more than giant bits of cosmic rubble, but many of them are much more — dynamic, even violent, and in one case at least, maybe capable of supporting life. What makes many of these satellites special is what’s known as tidal heating — a gravitational squeezing that takes place as the moon orbits its parent planet and is periodically tugged on by its sister moons in nearby orbits. On Jupiter’s Io, this produces explosive volcanoes; on Io’s neighbor Europa, it means a water-ice crust with what may be a global ocean underneath. On Saturn’s Enceladus it means sparkling jets of frosty exhaust, trailing behind the moon like the smoke in a wake of a steamship. Now, scientists are coming to believe that what happens in our solar system may be happening all over the galaxy. A new study just submitted for publication by a pair of astrophysicists at Princeton University suggests that as investigators discover more and more exoplanets — worlds orbiting other stars — they might also discover tidally heated exomoons. This not only dramatically expands the scope of exoplanet research, it also represents a big step forward toward the field’s ultimate goal: finding worlds like our own — mirror Earths — that just might be home to life. Read more: science.time.com/2012/10/15/never-mind-life-on-distant-planets-what-about-distant-moons/#ixzz29PlSNbxa
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Post by Deleted on Oct 15, 2012 18:23:53 GMT -6
Last night I watched Jupiter occultate Io. I try to watch these occultations every chance I get. The transits are the best though because I can see the shadow of the moons travel across Jupiter's disc, really cool! Last night I had one of the best night's of observing so far and saw many different galaxies and star clusters. It was just amazing !
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Post by satansrini on Oct 15, 2012 22:45:23 GMT -6
Sorry, I haven't read the whole thing and I will read in a bit. However, I will make a post blind based on the topic heading.
Exo-moons yes is the next step to finding life after exo-planets. But from what I have studied and understand, finding exo-moons is atleast 50 times tougher than finding a right sized exo-planet as such. Plus the size of the moons is smaller typically than the size of the rocky planets, let alone the gas giants that have becomes so easy to identify these days.
The relative motion of the moon with respect to a planet, which in itself is not self-luminating makes it tougher to identify the moon itself. And I think the biggest exo-moon if we find one will be about 1 1/2 times the size of earth. Assuming a planet like 10 times size and mass of jupiter and then the exoplanet's size.
They have just started discovering the smaller planets that are about 3 Earth massess. They haven't even identified planets that of the size of Earth and Venus yet. The other planets that they think will support life and they have suspicion about those planets being terrestrial are also today atleast 5 Earth masses.
So Exo-moons I think is another 10 - 15 years away. But ABSOLUTELY. They are destinations too.
Regards, Srinivas
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Post by Deleted on Oct 16, 2012 2:46:37 GMT -6
Sorry, I haven't read the whole thing and I will read in a bit. However, I will make a post blind based on the topic heading. Exo-moons yes is the next step to finding life after exo-planets. But from what I have studied and understand, finding exo-moons is atleast 50 times tougher than finding a right sized exo-planet as such. Plus the size of the moons is smaller typically than the size of the rocky planets, let alone the gas giants that have becomes so easy to identify these days. The relative motion of the moon with respect to a planet, which in itself is not self-luminating makes it tougher to identify the moon itself. And I think the biggest exo-moon if we find one will be about 1 1/2 times the size of earth. Assuming a planet like 10 times size and mass of jupiter and then the exoplanet's size. They have just started discovering the smaller planets that are about 3 Earth massess. They haven't even identified planets that of the size of Earth and Venus yet. The other planets that they think will support life and they have suspicion about those planets being terrestrial are also today atleast 5 Earth masses. So Exo-moons I think is another 10 - 15 years away. But ABSOLUTELY. They are destinations too. Regards, Srinivas I remember you mentioning this on a thread last year I believe which I found interesting and have thought about it quite a bit since . If most of the other solar systems that are out there have the quantity of moons like our solar system does, then that is going to make a huge number of possible candidates for life. Also, since (f) force = (g) gravity x (m) mass starting with the size of the star, than the planet, and finally the moon as being 1,2, and 3 and so on without going deep within the equation the star itself that these bodies are orbiting will play as a huge factor in the calculations . The size of the planet also, whether it be a gas giant or not as well. Consider though, that our own moon has a small amount of gravity which orbits our Earth. Depending on the star being orbited, the size of the planet, and then the size of the moon in question , it would be even better I would think on an Earth gravity scale for the mass of those bodies to be larger so that there would be more gravitational attraction to the lunar body. It's difficult to explain when describing and comparing other systems with similar forces to our own. The odds are in their favor for being possible candidates on lunar bodies. I'll have to look at Drakes equation and see if he included them or not.
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Post by satansrini on Oct 16, 2012 8:13:19 GMT -6
Hmmm.. No.. Drake did not include moons. But Drake Equation is very simple and I think you can expand it by including moons and the say.. "Drake-Touched Equation" ;D
Il call it by that name henceforth!
I was talking about a the concept of a 'moon to moon' yeah. But I don't think they have yet discovered such phenomenon. If i said that to a scientist now, may be he will laugh with his/her "you know what"!
What I said back then was imagine, A star that is like 10-20 times the size of Jupiter, than some planet of say the Size of Uranus will revolve around it and say a moon the size of Earth will revolve around it and then a moon the size of our moon will revolve around the 'moon earth'! Like a moon to a moon. Certainly, the laws won't prevent it. Its is - in my view that is - theoretically possible.
Regards, Srinivas
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Post by skywalker on Oct 16, 2012 11:08:13 GMT -6
Yes, it is possible. The very fact that planets have moons orbiting them while they are orbiting the sun proves that it is possible. I suppose that it would depend some on the size of the moon. The larger the planets and moons are the greater the chance there could be moons orbiting moons with maybe even more moons orbiting those moons. That's a lot of moons! What really amazed me about the article that swampy posted is that the scientists said they were surprised to find that what happens in our solar system might be happening in other solar systems throughout the galaxy. Like...duh. Did they never consider that possibility before?
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Post by satansrini on Oct 16, 2012 11:20:45 GMT -6
Hey Touched,
What is 'occultate' by the way?
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Post by Deleted on Oct 16, 2012 19:13:04 GMT -6
Hey Touched, What is 'occultate' by the way? When a larger body goes in front of a smaller body. This can be our moon going in front of a star or planet, or be another planet like Jupiter in front of Io as it spins in it's orbit. A transit is just the opposite. It happens when a smaller body travels in front of a larger body which is what happened recently when Venus went in front of the sun. In either event, many different precise calculations can be determined.
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Post by Deleted on Oct 16, 2012 19:16:52 GMT -6
Hmmm.. No.. Drake did not include moons. But Drake Equation is very simple and I think you can expand it by including moons and the say.. "Drake-Touched Equation" ;D Il call it by that name henceforth! ;D ;D ;D - I can only wish I was good with math. To an extent, yeah,,,but I have my limitations. It's something I need to refresh on and improve a bit.
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