New Moon Found Orbiting Neptune 120
Dave Knott writes "A tiny, previously unknown moon circling Neptune has been spotted by astronomers using the Hubble telescope. The moon, which is currently known as S/2004 N1, was found on July 1 by Mark Showalter of the SETI Institute in Mountain View, Calif., NASA announced Monday. It is less than 20 kilometres wide and its orbit is 105,000 kilometres from Neptune, between those of Larissa and Proteus, two of Neptune's other 14 known moons. It circles Neptune once every 23 hours."
But wait... (Score:4, Insightful)
Since Pluto is not a planet anymore, we shouldn't be allowed to call a 20 km wide rock a moon. Let's have a big convention to decide how we should call it.
Re:But wait... (Score:5, Funny)
Re:But wait... (Score:5, Informative)
The dividing line between "moons" and "rings" seems to be shared orbits, otherwise every little rock and/or ice ball in the outer planets' rings would have to be a "moon". A 20 km rock (or whatever) has enough gravity to sweep the space through which it passes, either clustering smaller bits into rings, adding them to its mass, or ejecting them from the planetary system.
Remember, Pluto was only a "planet" because we didn't realize it was an instance of a much larger class of KBOs. Now it appears to be more like a cluster of bits orbiting a mutual center, different from the planets and their moons, which have an orbital center deep inside the respective planets. Even without the companion bits, though, it's still a KBO.
We had already separated the "asteroids" from the 8 planets.
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Remember, Pluto was only a "planet" because we didn't realize it was an instance of a much larger class of KBOs. Now it appears to be more like a cluster of bits orbiting a mutual center, different from the planets and their moons, which have an orbital center deep inside the respective planets. Even without the companion bits, though, it's still a KBO.
Also, we once found a "planet" (Ceres) between Mars and Jupiter, and then another (Pallas), and then came Vesta and Hygiea. And then we realized that what was in between Mars and Jupiter was an asteroid belt.
We don't go around demanding Ceres be called a planet again because (a) it isn't, and (b) all the people who may have thought of it that was are now dead. This 'Pluto Restoration Society' will go away when those that can't adjust their mind to the reality of the universe die off. See Kuhn's "The Structu
Re:But wait... (Score:4, Interesting)
Also, we once found a "planet" (Ceres) between Mars and Jupiter, and then another (Pallas), and then came Vesta and Hygiea. And then we realized that what was in between Mars and Jupiter was an asteroid belt.
The asteroids were known long before Pluto was discovered, though. And classified as asteroids for over a century by then.
As for which one was discovered first, Ceres was the first registered, but there are historic data hinting at Vesta having been known in earlier times - it's at times visible to the naked eye.
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Perhaps more relevant ... Ceres (the first asteroid) was discovered in 1801, but the increasing number of bodies discovered in that region didn't lead to the proposal and implementation of the term "asteroid" until 70-ish years later after the introduction of photography as an astronomical technique (and several years more to become accepted practice) ; Pluto was discovered in 1930, and
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The Earth and Moon are "a cluster of bits orbiting a mutual center".
The center-of-gravity of the Earth-Moon system is inside the Earth. For the Pluto-Charon system, the COG is outside of Pluto.
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Remember, Pluto was only a "planet" because we didn't realize it was an instance of a much larger class of KBOs.
No, Pluto was a planet because it was a predicted discovery - it was named a planet before it was discovered. Percival Lowell calculated a possible path for "the missing planet" based on what looked like discrepancies in Neptune's orbit.
Clyde Tombaugh then found "it", and was convinced it was Lowell's Planet X. That what he found near where the incorrect calculations pointed wasn't going to have any noticeable effect on Neptune's orbit didn't stop Lowell Observatory and the press from calling it a planet.
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Cite please.
No. Do your own homework. Googling "pluto discovery" should give you boatloads of material.
As for the part you bolded, you cited that just fine.
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A cheek?
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That's no comment!
Re:But wait... (Score:5, Informative)
The IAU uses "moon" and "natural satellite" synonymously, which in this context refers to any natural body in a bound orbit of Neptune. I'm not sure why you think a 20km rock would fail to meet that definition.
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So you are saying it is a no-go? Damn it, I had a lot of fun last time I was at the assembly in Prague. Since I am solar system specialist, for sure I would have had budget from my employer to go to Honolulu in 2015 but I guess you just ruined everything...
http://www.iau.org/public/themes/pluto/ [iau.org]
http://www.iau.org/science/meetings/future/general_assemblies/1024/ [iau.org]
http://astronomy2015.org/ [astronomy2015.org]
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See if you can start an argument over whether "stable orbit" is properly defined given the many-body problem. I figure that's got at least one good weekend symposium in it.
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Moon shaped!
Re:But wait... (Score:5, Informative)
How about specifying it must have enough gravity to make it round to be called a moon and not just a satellite?
That would reduce the number of moons in the solar system rather dramatically. Mars, for example, would no longer have any "moons" as neither Phobos nor Deimos meet this definition. In fact both Phobos (11.1 km) and Deimos (6.2 km) are smaller than this newly discovered moon of Neptune (20 km).
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Re:But wait... (Score:5, Funny)
Too small to call it a moon, huh? Well... how about a "planet-orbiiting object" or "poo" for short?
As in, Neptune has a bit of poo right over there... Scientists suspect it came out of the moon.
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would have been MUCH better if it had been around Uranus...
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Pluto was the eleptical orbit witch
I always knew orbital mechanics was a dark art.
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As the title reads... New moon found orbiting Neptune.
Not Pluto.
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Let's have a big convention to decide how we should call it.
It doesn't matter how you call it -- it's not gonna come. :p
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Hehe ;-) you would be surprised on how good I am to call things.
https://www.youtube.com/watch?v=b1y_U4s6jfs [youtube.com]
Meh.... (Score:4, Insightful)
I like our moon better.
But honestly I have not been to either.
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Our moon doesn't even have a name.
Neptunes are called "Larissa", "Proteus" or even "S/2004 N1", ours is just called "moon".
It's like living in "country" in the village of "village" in a house on "street" or naming all your offspring "child".
well (Score:1)
Neil Armstrong commonly referred to it as 'Luna' and if anyone should know its proper name, it would be him
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He didn't refer to the moon by name. He referred to it with the Latin word for it. In science, you know, Latin is pretty often used... :)
Re: Meh.... (Score:3)
... Luna isn't proper enough for you?
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Same problem non-name in a different language.
""The moon is a moon" in English is "La luna es una luna" in Spanish.
(I trust Google translate is good enough not to mess up the spanish in this simple sentence).
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I don't get the point you're making about the translation. Are you saying that google translate should be able to pick up the nuance in that sentence and return a different word for moon if the Spanish use different words for our moon and a moon?
You're general point is interesting though - are there any languages that do use different words for the two?
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You're general point is interesting though - are there any languages that do use different words for the two?
That's not very likely, seeing as the generic term is derived from the original proper name.
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Same problem non-name in a different language.
""The moon is a moon" in English is "La luna es una luna" in Spanish.
(I trust Google translate is good enough not to mess up the spanish in this simple sentence).
But, "Luna es una luna" is not just Spanish, "Luna" is latin, it just happens to be spelt the same way as a Spanish word.
Bender, is that you? (Score:2)
Being derived from != equivalence. You aren't your grandfather, are you?
Also, in Latin the word declines. In Spanish it doesn't.
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At least it has a dark side. I wonder how many moons have a dark side in the solar system. Meaning, rotation period around its planet equals rotation period on itself.
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Dark in "Dark Side of the Moon" means "unknown", in the same sense as "Darkest Africa" or "Dark Arts". Nobody thought the sun didn't rise in unexplored Africa - though there seems to be a convention that Dark Arts are practised at night in dark robes.
Hey, if I do my Dark Spells on the beach in a Hawaiian shirt, maybe nobody will notice. World domination, here I come!
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There is no Dark Side of the Moon really...
Matter of fact its all dark...
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This phenomenon is called tidal locking [wikipedia.org].
From Wikipedia:
Most significant moons in the Solar System are tidally locked with their primaries, since they orbit very closely and tidal force increases rapidly (as a cubic) with decreasing distance. Notable exceptions are the irregular outer satellites of the gas giant planets, which orbit much farther away than the large well-known moons.
Pluto and Charon are an extreme example of a tidal lock. Charon is a relatively large moon in comparison to its primary and also has a very close orbit. This has made Pluto also tidally locked to Charon. In effect, these two celestial bodies revolve around each other (their barycenter lies outside of Pluto) as if joined with a rod connecting two opposite points on their surfaces.
The tidal locking situation for asteroid moons is largely unknown, but closely orbiting binaries are expected to be tidally locked, as well as contact binaries.
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Eventually the Earth will also become tidally locked to the moon, so a month and a day will be the same.
Apparently builders and plumbers already operate on this calendar.
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Or living on a lump of earth called "Earth" orbiting a sun called "Sun" in a universe called "the Universe".
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Due to sitting inside it, rather than on or outside it, it had a name bases on its appearance seen from the inside long before we realised that there wer other similar things, which we saw from the outside. Though "galaxy" is only "Milky Way" in Latin.
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Our moon doesn't even have a name.
Yes it does - it's called 'The Moon'! :)
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Neptune is singular, and it's called Neptune.
Stop making shit up, you idiot.
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I think the point is that the planets were named after various gods long before they were recognized as other worlds (the word planet originally meant "wandering star") Those names stuck (Neptune, Venus, Mars, etc), and by the same convention the Moon was named after the goddess Luna (or Selene, depending on the source mythology). The two remaining major celestial bodies, the Earth and Sun, get special treatment because from our perspective they are special. Earth is named after what we see of it: dirt,
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Me too. The tidal forces it creates makes Earth a far more diverse place. And interestingly enough, there are biological rythms based on it. There are no other planets in our solar system with such a significant moon.
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It was identified using data that was originally gathered in 2004-2009, but it was only found this year; it would appear that by convention the earliest data indicating its presence provides the discovery date, regardless of when the data was actually looked at.
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There was a moon in that search result?
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Planets and moons are just objects (Score:4, Interesting)
Thinking of 'planets' and 'moons' is all nineteenth century 'science' - the edge of ascribing to God's plan and capturing everything observable in orderly lists, so that school-children have something to recite in groups: five continents, five senses, five races, seven seas, seven wonders of the ancient world, order species genus family class kingdom, and nine planets.
In reality, things don't work out that way.
Re:Planets and moons are just objects (Score:5, Insightful)
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> Jupiter doesn't even have a well defined solid surface
To be fair that is only speculation. Scientifically sound speculation perhaps, but until we can actually probe its depths there's plenty of room for surprises.
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Right then. So 'objects' are out. Does 'celestial bodies' work for ya? Oh, and you mention that 'the distinction between planets and moons is still a useful one' - can you give an example?
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defining that it goes around another object in a trajectory that it goes is more useful than knowing if it's a planet, moon, asteroid, comet or what.
just like it's better about a car to know how fast it is and how well it turns than it is to know if was labeled a sports car when it was sold.
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I remember having a discussion with my biology teacher: he claimed that humans don't have instinct - none, and why? Because the definition of 'instinct' involved stating that it didn't apply to humans. That's what these lists are: a way to win a discussion and if you can't win it, you just change the rules.
Yes, people need something they can relate to. Sure. But I'm not so sure that it would hurt if things were taught a little bit more to their specific merits: I remember how distraught I was when I learned
New Moon Found Orbiting Neptune? (Score:1)
Oh, god, not even the aliens are safe from Stephenie Meyer's literature!
I don't mean to troll but... (Score:1)
Trekkies (Score:2)
That's no moon... (Score:2)
... almost 12 hours till someone said it? Really?
That's no moon... (Score:2)
well, maybe it is.