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Kepler Mission Could Detect Exomoons
Lord Northern writes "According to several news sources, NASA's Kepler mission is said to be able to detect habitable moons orbiting planets in other star systems. Kepler is a space telescope designed to detect exoplanets. Its mission will have it orbiting the Sun for 3.5 years, after which we'll be able to tell if any of our neighboring stars actually have planetary systems around them. However, apparently we will be able to detect not only exoplanets, but also exomoons orbiting those exoplanets. The Kepler team came to that conclusion after running a computer simulation which found that the telescope was sensitive enough to detect the gravitational pull of an orbiting moon (PDF). This means that the data expected by the end of the mission is going to be very rich, and it is said that moons as small as 0.2 times the mass of earth could be detected. Further details about the Kepler mission are available from NASA."
Actually, according to the lightcurve measured by Kepler, it is one. My bad.
... that's no moon
by that logic a habitable zone is a complete farce as well considering that not all places in the habitable zone are habitable. [eg. Earth's moon]
It was on July 20th, 1969.
Table-ized A.I.
exactly. referring to the Earth's moon as habitable is dishonest.
How we know is more important than what we know.
I don't think their use of it is wrong. The title is "On the detectability of habitable exomoons", and the abstract clarifies that to detect "habitable exomoons", this research proposes to detect "habitable-zone exomoons" (that phrase with the -zone qualification appears 4 times in the abstract), because presumably the actually habitable moons will be some subset of those.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Or is it just that it never existed? (For certain values.) ^^
Any sufficiently advanced intelligence is indistinguishable from stupidity.
Given that Mars weighs only 10% of Earth, a 0.2 Earth-mass moon is large indeed.
That my generation (I'm 27) will never get to space, at the current rate nasa is being funded. Id kill to go to space or to another planet. I wish that instead of wasting money on worthless crap we focus more on ditching this rock and finding a better rock! Seriously though going to space would be total pwnage hopefully we will be able to do some 6th day shit and clone ourselves till the day we can go to another planet!
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Our moon is about 0.12 times the mass of earth.
So much fail. Being in a habitable zone doesn't mean it has to be habitable (hint: habitable means "can be habited"). That's like being a hobo in a rich area, it doesn't mean it's dishonest to call it a rich area just because there's hobos in it. That's like confusing "global warming" for "uniform warming".
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You just got troll'd!
We do we spend time looking for exomorons? As if we didn't have enough morons already.
If they're horny then what's the problem?
When talking about "habitability" in the context of Kepler Mission, it's more like "as much as Kepler can say about this object's Habitability". It's not necessarily that the planet or the moon are within the so called habitable zone. Since Kepler is able to analyze the atmosphere on some of the bigger objects, a planet within the habitable zone but with an invalid atmosphere or for example a gas giant would not be considered "habitable" by Kepler's standards. It also includes many other factors. Not just the location of the object within the habitable zone of its star.
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Distinctions are only meaningful if they clarify or help avoid confusion. In what way is "habitable moon" confusing at all? Certainly your first wording is more precise, but "habitable moon" loses nothing truly meaningful in translation.
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I think we should just call them moons instead of exomoons. In context, we already know they orbit exoplanets.
The summary makes one error, suggesting that Kepler is capable of detecting the gravitational 'wobble' caused by a moon. Rather, Kepler, or any system of similar sensitivity, is able to detect the transit of a moon, and recognize it as being distinct from that of the parent planet.
Understandable mistake, since all of the early exo-planet detections were made using the 'wobble' method (detecting the Doppler shift corresponding with a stars motion due to a heavy, close planet). However, the transit method, which measures small dips in the brightness as the planet passes in front of its parent star is far more sensitive, though more difficult to use due to noise constraints.
Basically, imagine if you were looking at our sun from another star system, and Jupiter stood out clearly as a dip in the light curve, reappearing every 8 or 9 years(?). With this, something like Io or Europa would show up as a smaller periodic variation overlaid on that larger dip. Only noise levels are standing in the way of detecting it, and apparently they think Kepler can handle it.
any given point in earths orbit is completely inhabitable for most of the year as well. The only exception is when the earth is there. Earths moon lacks the mass to contain an atmosphere at its temperature.
A planet like jupiter or larger (as many such large planets have been found) in the "green" zone around a planet could easily have an earth sized moon orbiting it. That is what they are talking about when they mention habitable moons.
It was only habitable with whatever they brought from Earth (air, food, water). Not exactly vacation home material.
Lame-ass physics geeks have no appreciation for puns.
I'm already surrounded by Exomorons. Who'd choose to live with them?
No not zero at all. Nowhere near zero in fact. Chance is probability, and the probability is defined by the number of planets, which mathematically works out to "quite a lot".
Only if you ignore reasonable sub-light travel times. If you don't, it becomes "very, very few" instead. This comes up with the SETI project when you consider the number of starts with in a mere 100 light-years of us. There are only 511 G stars (those like our sun) in that distance and if you narrow the volume to a 50 ly radius, there are only 63 G stars. Within 20 ly, you can count the number on one hand -- 4.
(Note: We don't have any known, non-speculative technology that could get us above 0.1c, so I think I'm safe in considering a 1000 year trip to be unreasonable.)
The closest Earth-like planet we've found is 20.5 light years away around Gliese 581. The Wikipedia article I linked to goes through a lot of the possibilities for habitable planets, but there's a lot of uncertainty there.
Keep in mind that if you want to find a planet as good as Earth (much less better) you need to match all of the following criteria:
1) Earth-like gravity.
2) Earth-like temperatures and season.
3) Earth-like atmosphere (right mixture of nitrogen and oxygen; no toxics; right pressure; not too turbulent).
4) Earth-like rotational period (daily and yearly for growing crops).
5) Earth-like sunlight (intensity and wavelengths).
6) Earth-like water (not too dry; not completely water-covered; not iced over; non-toxic).
7) Earth-like tectonics.
8) An ozone layer and strong magnetic belts or some other means of deflecting harmful solar emissions.
Additionally, you might like to find arable soil, edible native species, a good supply of metals and other heavier elements, and other niceties. You might also hope not to find any surprising difficulties like high radioactivity, pervasive heavy metals, highly aggressive native species, etc.
That's just to find a *livable* planet. To find one that's *better* is just probably never going to happen. Not only is it hard to define what "better" means to a species that's adapted to its own world (and not only is "better" likely to only apply to a narrow subset of the available biomes of an entire planet), but it's just so improbable in the space we have to work with. If we ever do live on a better world, it will be because we *made* it that way, and it won't happen in our lifetimes without a radical breakthrough in physics followed by an equally great breakthrough in economics and politics.
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It was certainly a lot more hospitable than the "surface" of Jupiter, or even more realistically, the surface of Titan or Io. Neither of those two places are something I'd like to visit, even if the vistas are stunning.
The problem with defining a habitable zone is that currently we have a sample size of one. That makes statistical analysis of the topic difficult to do on an extreme level.
Assuming that the sample size can be increased, perhaps more statistical confidence can be gained to gain a proper conclusion. Discovery of life on Mars or Europa, to give some examples, might at least open up some potential and allow finer gradients of classification for "habitable" as well.
Even those two worlds being added as a "maybe" only puts the statistical sample size at 3. Not exactly a huge confidence interval for conclusions.