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Three Neptune-sized Planets Found Nearby
WillAffleckUW writes "CNN reports the discovery of three Neptune-sized planets found in orbit around a sun 41 light years away. The star they orbit is similar to our Sun, and the planetary distribution is probably similar to our Solar System. Recent observations by NASA's Spitzer Space Telescope last year revealed that HD 69830 also hosts an asteroid belt, making it the only other sun-like star known to have one. No word on if they have habitable moons, or monoliths yet."
I'm curious how you came to the conclution the odds of a more advanced society is only 50-50.
There are two things involved in this: one, do they have the ability to become more advanced (or are they limited by intelligence to less then current levels), and two: how long would an advanced civilization survive?
If you assume that an advanced society cabable of intersteller transport and teraforming could survive indefinatly (or at least more then 100k years past space travel), there is a far greater chance of them having better technology then worse.
Another interesting question: is it possible to design artificial intelegence smarter then yourself? If so, said intelegence could then create an intelegence greater then themselves ad infintium, meaning that relitive intelegence of the original species is irrelivent.
Does a line appended to your comment give your post meaning in and of itself, or only in relation to those without?
We might not have the technology to travel there physically in my lifetime (or lifespan, whatever) but that should be close enough to warrant some refocusing of more than a few SETI dishes. And for the longer term maybe a satelite designed to last 500 years to send there. This might be a project worth investing in even though we will be long gone before it would achieve fruition.
We are all just people.
To put 41 light years in perspective let's see how long it would take to reach this solar system. We'll assume the spacecraft will be traveling at the same speed as the Hellos 1 spacecraft, 252,800 km/h (158,000 mph). 41 light years is about 3.9 × 10^14 kilometers. That would take roughly 175,000 years to reach. As far as I know Hellos 1 and 2 were the fastest space crafts ever made, though I could be wrong. Suddenly 41 light years doesn't seem to close.
In the scale of the universe 41 light years is pretty insignificant, but just because it's insignificant in a cosmic sense doesn't mean it's insignificant to a species stuck on a backwater planet on the fringe of one of many galaxies.
I'm really impressed by the speed of progress here. I'm hoping that in ~30 years, we'll actually be able to SEE these planets. That's really exciting!
I'll form my OWN solar system! With blackjack! And hookers!
I realize you were citing Contact, but consider that inhabitants of said planet would be watching on TV right now. They're only about four years away from seeing a broadcast of our first moon landing.
after we started beaming massive amounts of radio and tv into space
What with dispersion, atmospheric absorption, and general background interference from the sun and other far more powerful sources of radio waves, I reckon aliens would have a hard time picking up TV stations from mars, never mind light years away. I mean in real terms, what are the odds that anything except a very, very powerful radio telescope pointed directly towards earth and listening on the correct wavelengths is going to pick up anything but background static? Fairly minimal I reckon.
Besides which given another 200 years or so we are probably going to invent or discover some entirely new and far more efficient means of communication than radio, and the first scientist to turn it on is going to be blasted out the window by the storm of alien TV and radio he just tuned in to.
What he can't kill, he has sex on. Trent.
I agree that aliens finding US, by way of travelling through our radiosphere is far more likely than us finding the aliens, and I even expect that to happen well before my hundredth birthday, in 2065. It's easy to see why this is likely: plot a sphere 150 light years in radius against the size of the milky way galaxy, and you will see it is a non-trivial portion of the entire thing. (i.e. our radiosphere is actually easily visible when viewing the entire galaxy.)
However, I can not for the life of me figure out why you say the chances are 50/50 of them being more advanced than us.
I think that it is almost impossible any radio-using aliens exist within a hundred light years of Earth - as SETI would already have picked up those signals.
So, given it is 41 light years away - it is easy to say that no inteliigent life forms which use radio waves exist there.
Of course, us looking for radio waves might be like Sioux Indians trying to intercept telegrapgh signals by looking for smoke signals on the horizon...
It's likely that no self respecting civilisation would ever THINK about using the electromagnetic spectrum to communicate with, and it seems likely (to me at least) that all emerging civilisations will go through an electromagnetic "phase" until they find gravity waves, or FTL comms. This being the case, we'll never intercept ANY radio waves at all from aliens.
Mostly because, if we lean towards Drake, then the number of space-faring civilisations in our galaxy is at best, 40, and at worst 1 (That's if you actually DO count Earth as "civilised"!). If it's one, the answer is easy - if it's 40, then the likelyhood of us finding them is exceedingly low. 40 civilisations spread randomly through the "blue donut" of habitable areas in our galaxy would mean being separated by many many hundreds (and probably thousands) of light years - I haven't done the math.
Drake boils down to "Number of alien space-faring civilisations in galaxy = number of years those civilisations last". Ours has lasted 40 years... and that's giving us a HUGE benefit-of-the-doubt.
Anyway, the chances of any other civilisation being more advanced than us (if we believe Drake) is almost zero. If he is correct, then WE are the most advanced race, and are close to self destruction, while the others still attempt space travel.
The longer we survive, the more likely it becomes, that we will discover other races, and the longer we survive, the more likely it is that we will encounter them at levels BELOW where we are today. That's if we find THEM.
Of course, I'm convinced that THEY will find US, and they'll be far more advanced than us. The only question is - when?
How many escape pods are there? "NONE,SIR!" You counted them? "TWICE, SIR!"
Assuming that Bode's Law applies there, it's a reasonable assumption that a planet resides within the habitable zone around that star.
However, unless it has through some miracle of coincidence a large moon to provide the environment of constant change via tides and crustal flexing, I doubt that Darwinian processes would have had the time to produce an ecosphere like ours. Maybe something along the lines of the Paleozoic era might be possible.
But then, with an asteroid belt comes catastrophic encounters, and maybe that would be the larger driving influence for Darwinian change.
But in any case, I doubt that the coincidence would be strong enough to extend to a similarity of geography that would support an ecological mechanism similar to ours, that regulates climate change between two quasi-stable regimes.
Quite possibly, once life developed on such a world it might quickly drive it into a greenhouse state like Venus, without the mechanisms that switch us between greenhouse and icehouse that we have.
Yes, there is a limit.
That limit is 6 solar masses. Think about it: 6 times the mass of our sun. Made of rocks.
Why the limit? Because that is the mass of an object, after which it will collapse in on itself to form a black hole. I don't know enough of the science to be able to state at what point the center of the planet begins to form neutronium, but the surface at least, will remain rocky, until the object does completely collapse.
Rocky is just "rocks" and rocks are happy to sit in a very high level of gravity. Your 5 solar mass rocky world might have mountains that reach as high as 3 or even 4 millimetres, and fantastically deep trenches up to 2 mm deep might form during "earthquakes".
The only questions in my mind are:
1) How long after the thing stops accreting material does it take to form a rocky surface?
2) What is the surface gravity of a 5 solar mass rocky world?
3) At what point does the interior begin to form Neutronium.
How many escape pods are there? "NONE,SIR!" You counted them? "TWICE, SIR!"
http://outcampaign.org/
Suppose one light year is 1 km. Then the tinyest speck of dust on the monitor is about 5 times bigger than Earth (1 micron), Sun is about half the size of the dot above i (0.1mm), distance from Earth to Sun is the length of the word "length" (1.5cm). The size of the Solar system (Pluto orbit) is about the size of your computer - 0.7 meter. The most distant objects in Oort cloud are probably within your room (a few meters). The nearest star - 4km away, like a gas station. The new planets are 41km away - the state border :-). Our Miky Way galaxy is a few times larger than Earth, maybe half way to the Moon. The nearest spiral galaxy is not too far - just 8 times more distant than Moon. The edge of the Universe (12 bln l.y.) is about the size of Sedna orbit.
So, 41 light years is relatively near :-).
IANAP (I Am Not A Physicist), but my bet would have been on the Chandrasekhar limit there, which puts the limit at a little under 1.5 solar masses. (Admittedly, that does change with the chemical composition, so no idea how that works for heavy enough elements associated with "rocks".) Since we're talking a planet, not a star, I'll assume there was never nuclear fusion in the centre to generate extra pressure, so the limit would be purely and only the limit at which degenerate electron pressure is no longer enough.
Also, rocks (solids, metals, whatever) may be happy to sit in high gravity, but not _that_ high, or not without remaining the same kind of thing one calls a "rock" in casual conversations. A mass supported by electron degeneracy pressure isn't quite the same as the mostly crystalline structure you'd have in mind for a "normal" rocky planet.
I'm also not sure if it would form mountains or trenches (even 3 to 4 mm high) at that point, since the whole thing is held together by the quantum pressure of a "gas" made of electrons. It's, so to speak, some atoms "floating" in that electron gas. What keeps it from collapsing at that point isn't a crystalline structure that can be re-shaped to form a mountain or a trench, but just the fact that getting any denser would force the electrons to occupy even higher energy states, thus increasing the pressure, thus pushing it back into shape. So at a wild guess, that thing couldn't form any long lived mountains any more than you can get mountains on Jupiter.
I'm also not sure if you can get just a little neutronium in the centre, while leaving the surface intact. The way I understood it (but again, IANAP) once it does start to collapse into neutronium, then it goes all the way. (Maybe also blowing a part of itself into space, supernova style. The fast collapse will produce enough energy for that.) If the pressure is enough for the centre to collapse, this will just produce an avalanche reaction where the collapse both increases the gravity (less R --> more g) _and_ takes out some of the electron gas that supported the star to start with. So basically it's like puncturing an inflated balloon: it won't stop at losing just a little gas.
That's why we talk about the Chandrasekhar limit as a hard limit. In fact, hard enough to use Type Ia supernovae as a standard candle for really long range astronomy. You can know pretty exactly at what mass the star went *BOOM* and exactly how bright that explosion was. Because it happened as soon as the star went even a just a tiny little bit above that limit. When that happened, it didn't just get a little neutronium in the core, but started the final countdown.
But again, IANAP, so I'd be curious to hear about it from a real physicist.
A polar bear is a cartesian bear after a coordinate transform.
Their response could come in 2018. Cool.
Seems to me that some form of pacifism would pretty much be a necessity for any intelligent species to survive beyond a certain technological threshhold
I've heard this before, and the reasoning is a bit suspect. I mean, do you think its coincidence that the greatest advances in technology were achieved during times of war (hot or cold)? I certainly don't. Chances are that the most advanced species are the most competitive or warlike, and the pacifists reach a state of equilibrium (stagnation) with their environment for a few million years before the other races find them and wipe them out.
What he can't kill, he has sex on. Trent.
Come on man. This is Slashdot, wtf is football?
Look it up.
How many more world wars can we sustain before we either detroy ourselves or knock ourselves back into the bronze age?
When open war is no longer a feasable option, the battlefield merely shifts, as history has shown us (for example the cold war).
But you have very little to base this prediction on.
Except, for example, Genghis Khan. I'm sure a few hundred other examples could be applied.
Look at Europe, for example. They've FINALLY found peace after hundreds of years of nearly constant warring.
Sixty years of peace hardly qualifies as a good example. And I should point out that the formation of the EU began on economic grounds, in the face of a far more competitive US.
Look at Japan. They have almost no military.
Japan has no military because it is under the aegis of the US, with US bases and forces in place to protect it. Furthermore is has received massive amounts of foreign aid from the US to prop up its economy, in the name of being a bulwark against communist China, aid which extended until relatively recently. Now that the aid has ceased, guess what? They are jockeying for their own military forces again.
So I don't buy this idea for a second that we must continue fighting and competing with our brother in order to avoid "stagnation."
Oh I didn't say that. I'm just pointing out the iron hard evidence to the contrary. Frankly I really don't have an opinion on the matter, but if it looks like a duck and quacks like a duck...
And if we go out into space with guns blazing, they might just decide to squash us like annoying bugs.
I completely agree. Therefore the likelihood of us getting squashed like bugs is quite high, I reckon.
I'm sure someone already knows we are here.
I'm not sure where you get that certainty from; unless you have access to some information the rest of us don't possess, I'd say rather the chances are extremely high in the opposite direction, based on what I know.
In summary I should say I am as pro-peace as the next man, and I think war is an evil that must be stamped out, and soon. The preponderance of evidence is distinctly in favour of aggressive expansionist cultures gaining the upper hand technologically however.
What he can't kill, he has sex on. Trent.
I should point out that using the Doppler techinque can only provide an estimate of the MINIMUM mass of the object. The masses of the planets are not smaller than that of Neptune. It depends on the inclination of that solar system to our line of site. Only when we see the system edge-on, is the actual mass the same as the minimum mass. Since we can detect the asteroid belt with Spitzer, it's a pretty good guess that the system is close to edge-on in this case. But in most cases, you can't tell. Press releases of exoplanet detection tend to neglect this issue.