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Our Moon Could Become a Planet
anthemaniac writes "Earth's moon is drifting away from us more than an inch every year. In a few billion years, if the system survives, the moon would be reclassified as a planet under the new IAU definition. You gotta wonder if the astronomers who dreamed this definition up had thought of that."
That's no moon!
both the Earth and Moon will have been swallowed up by the Sun when it becomes a red giant...
Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
"The sun will turn in a red giant before the moon gets far enough away to be classified as a planet"
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In a billion years propably the defintion of planet will have a few thousand updates.
The problem will fix itself in time I guess.
...oh well, forget it, it's still a moon.
...at least the tallest ones.
Reminds me of that old joke telling that a quick computation on the evolution of this distance placed the moon 4 meters away from the earth 65 million years ago and thus explained why the dinausors died.
If you'd bothered to RTFA, you'd find that the moon would be reclassified as a planet when the systems center of gravity no longer resides inside the Earth.
I would gladly send my kid to this elementary school if they could prove that they could teach concepts like orbital decay and barycenters to to nine-year-olds.
Could you tell me what the 'current' definition is?
The problem was that there wasn't a definition before. More of just an accepted method of measurement. And it was arbitrary. I think it was generally based off of 'anything as big or bigger than pluto is a planet'. That's not scientific at all. The new definition is great. It relies on science to determine the status of 'planet' rather than something arbitrary picked out of the sky to satisfy what people had learned in grade school.
I really don't think humans will last another thousand years (with the way we're poluting the environment and declaring war on each other plus the rising threat of nuclear weapons) let alone another few billion years. And provided we do last that long, I'm sure the standards for classifying planets will have changed hundreds of more times by then.
In fact we'll only be able to take one item of baggage, which will be a clear plastic bag containing essential items only.
And no electronic devices. Or Liquid.
Orbiting balls of rock won't even fit through the scanner.
"I would gladly send my kid to this elementary school if they could prove that they could teach concepts like orbital decay and barycenters to to nine-year-olds."
I would only send my kid there if they LEARNED it. I have a feeling they most nine-year-olds would be picking boogers during that class.
If a nation expects to be ignorant and free, in a state of civilization, it expects what never was and never will be.-TJ
I already consider the moon-earth as a bi-planetary system. What's the big deal with these definitions, anyway? No matter where you draw the line, there will always be cases where there will be discussion. Like the criterium that the object has to be "nealy spherical" because of it's own gravity. Lots of planetoids are somewhere on this vague border.
Comets, asteroids, planets, stars, they all have grey areas between them.
"It's too bad that stupidity isn't painful." - Anton LaVey
Wrong, wrong, wrong! Just RTFA. The moon does not have to escape the Earth's gravitational pull in order to be re-classified as a planet. The only thing that would be necessary (according to the new definition of a planet) is that the Moon moves further away from the Earth, just enough so that the barycenter of the Earth-Moon system is above the surface of the Earth. The Moon would still orbit the Earth. Obviously, the moderators who gave a +5 Insightful to your comment have not read the article either.
Please stop giving +1 Insightfuls to people who either a) haven't read the article or b) haven't undestood it. The moon could be reclassified as a planet EVEN IF IT STILL ORBITS THE EARTH. It depends on whether the center of gravity of the pair is inside the earth or not.
Please read my Canon EOS tech blog at http://www.everyothershot.com
We can just build a new moon. With blackjack. And hookers.
Don't blame me; I'm never given mod points.
People are already arguing over things that may happen in a few billion years? I don't even buy green bananas!
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The energy to lift the Moon's orbit comes from the rotational energy of the Earth, which is limited. As the Moon gets higher the Earth rotates slower. There may not be enough energy to lift the Moon high enough to qualifty.
In fact, forget about the moon.
It was a joke! When you give me that look it was a joke.
This is called a Twin Planet. And no it would nolonger orbit the earth the earth, the "moon" would orbit eachother at a common point. Either way, I see no reason that once we have this designation of moon vs planet why we should be so beholden of "our" moon that we can't accept it nolonger being a moon. We shouldn't change the definition just to fit some popular idea.
It was my understanding that the moon affects the level of the tides, not the mean sea level, which is far more a product of the Earths gravity and dependant sea water pressure/density.
Yes all those scientists must have missed that one, eh?, I am glad there are informed people like you in world to set them straight.
You are assuming that all the ice is in the seas, which it is NOT. A large amount sits on land in the form of Ice Shelves, there is enough to cover an entire contient (Antarctica) as well as most of Greenland and Canada, not to mention all the ice in Glaciers. As all this melts (and there is enough in Antarctia to contain 90% of the worlds fresh water) it wil flow into the sea and the sea level will rise, that is 'the big deal'.
But don't worry I am sure Mr President will give you a big pay rise for that wonderfully dismissive comment on the effects of climate change.
If this were really happening, what would you think?
No-one knows if the humans will survive that long, maybe there will be no-one to rename it.
A billion years? If our descendents exist by that time, they won't be considered human by our current definitions. I think it's a safe bet that the only way humans as we know them today could survive that long would be by either time-traveling or becoming a part of some aliens' (or dolphins') "Save the Humans" project.
I'm almost 26 and I'm picking boogers right now while reading these comments. (I'm serious)
A few billion years? Why should they care?
It was projected that in a matter of millions of years, the moon will cause the earth to stop rotating altogether. Without rotation, do you seriously think we will inhabit this planet?
For that matter, in a matter of millions of years, we should have developed a technology for making the earth rotate as fast as we wish, and moving the moon back where we want it to be. All it requires is enough rocket-power by even today's standards.
And over there we have the labyrinth guards. One always lies, one always tells the truth, and one stabs people who ask t
Calling Jupiter a "failed star" is like calling me a "failed super model" - I mean, yeah, there's some similarities between me and a super model but it's extremely unlikely anyone would ever mistake me for one.
IIRC, Jupiter has only about 1% of the mass needed to achieve fusion, so it's a long, long way from being a star. I, on the other hand easily have ten times the mass required to be a super model.
Clear, Dark Skies
If the moon going further away from the Earth causes the barycenter of Earth to drift outside its surface, then the Earth will be orbiting a point outside itself, with its orbit becoming greater the farther the barycenter drifts, until it peaks at one point. This is similar to Pluto constantly orbiting a point outside itself, as illustrated in this NASA chart hosted by Wikipedia. I think that when a moon begins to have that effect, it should be classified as a planet.
Currently, the Earth's barycenter is three-fourths of the way to its surface, causing it to sort of wobble, rather than fully orbit an invisible point. This is like an analogy: This is like a Chippendale stripper doing a pelvic thrust, rather than running around in a circle.
Earth's orbit around the sun currently makes the sun wobble in a barely perceptible fashion. Jupiter's orbit around the sun, however, causes the sun to orbit a point about 7% above its surface. I think that there should be a new class of planets for the purposes of describing a planet that makes a star orbit itself in this manner.
Clearly, all brown dwarfs orbiting a star would also have a similar or greater effect. The best way to describe it, in my opinion, would be by merely affixing "co-orbital" to describe a planet altering the sun's orbit in this fashion, or a brown dwarf orbiting a star doing this.
If this causes a planet to be "co-orbital" for only part of its orbit, or a natural satellite to be a planet for part of its orbit, in some eccentric situations, that's fine with me. There's one other issue with the new definition that makes me uncertain, though. EL61 is a "minor planet" that has a very oblong shape caused by its own orbit around the sun. If it were in a slower, closer orbit, its own gravity would almost certainly be enough to warp it into a nearly spherical shape. Should EL61 be considered a planet, despite its problem?
Consider 2 bodies of equal mass seperated by a distance of X.
The Centre of mass is right in the centre of the space between them.
The distance X increases by 1 unit, does the centre of mass also increase by 1 unit?
Adjust this equation to put it into earth/lunar context and you will understand why scientists don't just "google the math".
liqbase
"Of Time and Space and Other Things"
Which was a collection of essays on various interesting science stuff, though I don't know if any of it was published seperately.