Feels like we're playing the first round in "Master of Orion" when you start scanning the stars around you ;)
I still love that game.
Two potentially life-friendly planets found orbiting a nearby star
121–130 of 391 posts
Re: Two potentially life-friendly planets found orbiting a nearby star
#122"just 12 light-years away" I love the "just". I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-)
And "just" 24 years over radio if there's anyone there to talk with ;).
Why 24 years? Radio travels at the speed of light, not half the speed of light, right?
Re: Two potentially life-friendly planets found orbiting a nearby star
#123Being that close also offers us a better ability to examine it. The nearer the star, the more arc-seconds (or tiny fractions thereof) the star will appear in telescopes. 12ly is ridiculously close! It also tells us something interesting. If we presume there's nothing special about our little corner of the universe, then the distance to the nearest potentially habitable planets gives us an estimate of how many habitab…
> Only 12ly away and that one has maybe two habitable planets? That tells me the universe is teaming with potential homes for life. This seems like the birthday problem in statistics [0] - that if you have 30 people, it's likely that two people have the same birthday. However, the problem that could also exist (in our corner of the galaxy) that everyone else has a birthday far away from ours, and nobody else shares a…
The birthday paradox works because you are looking for a pair that has the same birthday, regardless of what date that birthday is. It doesn't work in the habitable planet sense because you would be essentially locking the birthday to a fixed date.
Re: Two potentially life-friendly planets found orbiting a nearby star
#124"Habitable" in also relative to our Earthly form of life. There may be other architectures that prefer different temperatures and pressures, perhaps.
Or aren't primarily carbon based whatsoever.
I highly recommend the book The Equations of Life: How Physics Shapes Evolution[0] . While it's be foolhardy to rule out other dramatically different forms of life, there are only so many candidates in the periodic table and only so many of those in common concentrations throughout the universe. The universal laws of physics that continually converge on the same solutions on Earth, and the fact that life has apparently failed to succeed even on nearby planets (perhaps at all, and certainly not advanced life) with different conditions suggests that it's at least unlikely to find life thriving at far different temperatures (atoms just don't hold together or move enough) or bases (I wouldn't completely rule out silicon, either, but the author makes a good case that carbon is far more likely)
[0] https://www.amazon.com/Equations-Life-Physics-Shapes-Evoluti....
Re: Two potentially life-friendly planets found orbiting a nearby star
#125Re: Two potentially life-friendly planets found orbiting a nearby star
#126Re: Two potentially life-friendly planets found orbiting a nearby star
#127Re: Two potentially life-friendly planets found orbiting a nearby star
#128And to think that there is likely an Easy Mode system out there.
A habitable planet on the low end of the mass spectrum needed for a stable atmosphere with other habitable planets in-system. And all that close to another star with habitable planets, possibly in the sub-lightyear range.
Basically everything ripe for a spacefaring civilization to grow without too much trouble and with plenty of motivation.
The Earth is hard to leave and everything else in our system is dead rocks with hellish environments as far as we know with the nearest alternative at least dozens of lightyears away
Re: Two potentially life-friendly planets found orbiting a nearby star
#129Earlier quoted context omitted.
I'm sorry, I'm not at all educated in this subject and I might be misunderstanding what you are saying, but isn't Earth the perfect example to argue against this? We're a life-friendly planet that isn't tidally locked?
It has to do with the class of star. This star is so cool that the only way for the planet to be warm enough to support life is for the planet to be really close to the star. I don't really understand tidal locking but I think it happens vastly faster at closer orbits - because there is a stronger gravitational gradiant closer to the parent body.
Tidal lock is caused by differential gravitational attraction. The half of the Earth currently facing the sun experiences more force pulling it towards the sun then the part facing away - which manifests as the spin of the planet having to do work against gravity to keep the spin going.
As a planet gets closer and closer to it's star, this gets more and more pronounced and all the various deformations and instabilities begin to favor braking the planet rather then it continuing to spin.