My fav thing about the universe is the idea that evolution + ingredients in another order could create something totally bizarre and wonderful!!
Seven earth-sized planets discovered circling a star 39 light years from Earth
331–340 of 754 posts
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#332Earlier quoted context omitted.
That actually sounds... more plausible than I would have expected. Like, doable with technology I can imagine being within reach in the next 50 years even if we don't achieve any currently-unforseen breakthroughs.
Which begs the question, why haven't we at least even tried to have done anything like this already? Do we really need to repeatedly spend comparable amounts of money on yet another dramatic TV special about humans traveling to Mars, as narrated by a favored celebrity? We really are running out of time. And it almost seems like it's pre-determined to happen. :\
The engineering issues are really tough, though surmountable. Currently, we just can't engineer the parts that will last that long in hard vacuum. Mostly because we can't test in that environment easily. Also, what do you do when all the light bulbs have burned out or gone haywire, what does that fault-tree look like for the billion and one parts on the craft? For a short journey of ~7 years, it's not a very big deal, it's just engineering issues. When you get into generation ship discussions then it becomes a human rights nightmare to trap newborns in a ship for their entire life and the lives of their descendants.
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#333Earlier quoted context omitted.
Of course, #askNasa didn't win me a question, but could any astrobiologists comment on this question: Tidal locking means the planets would always have a side facing the star, leading to very different thermodynamics in terms of climate and weather on the planet, not to mention radiation. Doesn't that very much hurt the chances for life on those planets?
The debate rages. The problem is that one side of the planet is essentially exposed to space and thus tends to be at cosmic background temperature, and the other side exposed to the star. It is thought by a lot of people that anything volatile enough to be a gas, ever (so, including water), would rapidly end up migrating over to the frozen side, so even if the planet started with the right mix of water and whatever o…
If water freezes on the dark side, moisture in the atmosphere would probably move from warm to dark side and fall down permanently as a snow gradually removing liquid water.
If the oxygen and nitrogen freezes and snows down in the dark side (-220 C or so), the warm side can't have atmosphere either.
Unless there is some way tidally locked planet can have stable air or sea convection between the sides. I don't think they have.
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#334"Due to its mass, the star has the ability to live for up to 4–5 trillion years" So when the rest of the universe cools off and stars start to die, Trappist one keeps on shining and shining... We need to get there. But first, let's get rid of our genocidal tendencies.
It's not just that one. The vast majority of stars, by number (but not by light), are stars like these. The universe might dim, but it won't be dark for a long, long time.
Yes, in all bayesian likeness this is a class of star systems that populates the universe. Suddenly the universe does not seem so dark and foreboding anymore.
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#335Earlier quoted context omitted.
What determines my speed limit? Is it set at 0 here on earth? What if I travel to another galaxy, this one was going at .5c relative to me when I was on earth. Then after trillions of years, inflation causes all of the galaxies to separate beyond sight from me in this new galaxy. Now, the centre of this galaxy appears at rest. Does my velocity get "reset?"
inflation/expansion of space is not limited to the speed of light.
I know. That understanding is already illustrated in my question... I don't see what that has to do with answering it?
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#336Earlier quoted context omitted.
Which begs the question, why haven't we at least even tried to have done anything like this already? Do we really need to repeatedly spend comparable amounts of money on yet another dramatic TV special about humans traveling to Mars, as narrated by a favored celebrity? We really are running out of time. And it almost seems like it's pre-determined to happen. :\
Isn't part of the problem that any ship capable of interstellar travel is also capable of being turned into a WMD? I imagine a lot of people would get really nervous if someone for instance parked a bunch of radioactive material in low earth orbit, and even with fusion there would be the fear that someone could turn the ship around.
To be fair kinetic bombardment is stupid easy to do once you can put stuff into orbit. Put a few, 20 foot long tungsten rods into orbit and you can effectively nuke, without radiation, any location that you orbit over [1].
Sure this is a problem but it's one that already exists today, not necessarily only when we start building space craft in orbit.
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#337See? I told you that seven is a magic number.
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#338Earlier quoted context omitted.
Which begs the question, why haven't we at least even tried to have done anything like this already? Do we really need to repeatedly spend comparable amounts of money on yet another dramatic TV special about humans traveling to Mars, as narrated by a favored celebrity? We really are running out of time. And it almost seems like it's pre-determined to happen. :\
The engineering issues are really tough, though surmountable. Currently, we just can't engineer the parts that will last that long in hard vacuum. Mostly because we can't test in that environment easily. Also, what do you do when all the light bulbs have burned out or gone haywire, what does that fault-tree look like for the billion and one parts on the craft? For a short journey of ~7 years, it's not a very big deal…
Yeah I'm to be honest just trying to awaken people to the priority being that we need to establish a self-sufficient colony somewhere other than Earth.
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#339Earlier quoted context omitted.
Just going that fast isn't really risky at all (assuming you don't hit anything, which isn't actually a safe assumption). The tough part is making something capable of a constant 1g of acceleration for a 7 year trip. Most of the craft we make only accelerate for the first small percent of a trip. We can do accelerations that high, but not for very long, and we can't even manage acceleration for such a long duration e…
If you go fast enough doesn't any incoming radiation just get blue shifted into gamma rays? Just running into cosmic dust at the speed of light would not be fun.
Isn't that the whole relativity theory: that if you emit a photon while at celerity 1c, it looks like it goes away at 1c both from you and from a still reference? hence blue is still blue at 1c?
Re: Seven earth-sized planets discovered circling a star 39 light years from Earth
#340To get a spacecraft there it would take: Accelerating at 1g the 1st half, and decelerating at 1g the 2nd half, the traveler would experience 7.3 years of time. For observers it would take 41.8 years at a max speed of 0.998c If you had a near perfect hydrogen -> helium fusion engine, it'd take about 6 million tons of fuel (about the mass of the Pyramids of Egypt or 2,000 Saturn V rockets)
That actually sounds... more plausible than I would have expected. Like, doable with technology I can imagine being within reach in the next 50 years even if we don't achieve any currently-unforseen breakthroughs.
The problem is far easier to state than implement.