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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."
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 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.
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 :-).