Earlier quoted context omitted.
Why is it certainly tidally locked when Mercury is not?
Mercury orbits in 88 days. This other place orbits in 5 days. And Mercury is almost tidally locked. Venus will be, before long.
Thx
Earth-like planet spotted orbiting Sun’s closest star
251–260 of 351 posts
Re: Earth-like planet spotted orbiting Sun’s closest star
#252Earlier quoted context omitted.
"Unlike the Sun, which will evolve into a red giant in 6.5 billion years and reach the end of its life at an age of about 10 billion years, Proxima will stay on the main sequence for another four trillion years due to its low mass and low energy production." They laughed at me when I bought investment property on Proxima Centauri b, but who'll be the one laughing in 10.000000001 billion years?
“Stars with a mass of less than 0.25 solar masses do not evolve into red giants.… Toward the end of the blue dwarf phase, Proxima will become considerably more luminous, reaching up to 2.5% of the Sun’s luminosity. Once it runs out of hydrogen fuel, it will evolve into a white dwarf, skipping the red giant phase, and gradually lose all its heat energy.” So we just need to tackle climate change and learn to live susta…
A good place to learn how to reverse entropy.
Re: Earth-like planet spotted orbiting Sun’s closest star
#253Earlier quoted context omitted.
This is absolutely, objectively, incorrect. You might as well argue that you can build a self-sustaining base on Antarctica. Of course you can't, because Antarctica can't support life. No amount of shouting into a bullhorn about adventure will change that. It might be possible with an absolutely epic effort to airlift soil, nuclear reactors, nuclear and other fuels, machinery for every eventually (including chip fabs…
> soil Both aquaponics and aeroponics provide ways to grow plants without soil. Breeding insects or algae may provide nutrition with very small amounts of mass needing to be transported. > nuclear reactors Yes, these are a necessity but we've sent one to Antarctica before and we could send a more modern one to Mars. > nuclear and other fuels The good thing about nuclear fuel is that you need a very small amount of it…
> Mars (and Antarctica for the most part) do lack anything biological in origin, no oil or wood or crops as feedstock for chemical reactions but there are always alternatives.
Ignoring energy sources (solvable using by a fission reactor), the entire Earth has a similar feedstock problem as Antarctica. There's plenty of hydrogen and oxygen there. CO2 can be mined from the atmosphere by plants. Nitrogen is the remaining building block of life. At this point, most of the nitrogen in human tissue was extracted from the atmosphere using the Haber-Bosch method (which, roughly speaking, converts atmospheric Nitrogen and energy to fertilizer).
I agree that Antarctica would be an easier (and safer) place to build the first self-sustained "moon base"
Re: Earth-like planet spotted orbiting Sun’s closest star
#254Earlier quoted context omitted.
Not must be. Is probably achievable, and is worth attempting, even at the cost of lives. You can argue from either the perspective of futility of attempt (no chance of success) or futility of outcome (success wouldn't be worth it), but I'm pretty convinced both would be weak arguments, both logically and historically.
I'm probably an optimist on Mars travel. I think, with a fuck ton of starships, you could get people living on Mars. But there's some big asterisks on that. You'd more or less have to live in the starships, dependent on shipments from earth, with self sufficiency failing on pretty much every category. Over a very long period, most people would probably die a bit earlier from radiation and dust. Not much would be prod…
Sounds like the early days of Australia. Maybe build a new Botany Bay? (Only half joking.)
Re: Earth-like planet spotted orbiting Sun’s closest star
#255Earlier quoted context omitted.
I only counted 5 (including Proxima Centauri). What are the six that you see?
Barnards Star, Lalande 21185, then Alpha Centauri, then Proxima Centauri, then Ross 248, then Gliese 445 makes 6. There are 6 if you count Proxima Centauri and Alpha Centauri separately; 7 if you count both stars in the Alpha Centauri pair separately, and 5 if you count Alpha and Proxima Centauri separately. Alpha Centauri is the binary system of Alpha Centauri A and Alpha Centauri B, which are separated by about 10-…
For reference, Saturn is about 9-10 AU from the Sun.
Re: Earth-like planet spotted orbiting Sun’s closest star
#256Earlier quoted context omitted.
Then they should have just called it a rocky planet. Earth-like is a massive misnomer/clickbait here.
It is the term used in planetary science. Not understanding something doesn't mean clickbait
Being the accepted term in the field doesn't it make it not click-bait. That just comes down to whether or not using the term in the headline baits people to click.
The abstract refers to it as "sub-Earth", and a "Earth-mass".
Re: Earth-like planet spotted orbiting Sun’s closest star
#257Earlier quoted context omitted.
I believe we are discovering that space isn’t as empty as we once imagined. Rock-hopping could be a viable method of (slow) interstellar travel.
Eh, we're talking about a section of an arm on a galaxy that we're in. I'm pretty sure there's nothing in between most galaxies.
Re: Earth-like planet spotted orbiting Sun’s closest star
#258Another point for anyone considering whether we should send a space-probe there... The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth. So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri. You'd b…
A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…
"...with today's technology..."
So we have the ability today to move 50K tons of parts into orbit, and come up with vast quantities of helium-3?
Re: Earth-like planet spotted orbiting Sun’s closest star
#259Earlier quoted context omitted.
If we really wanted to, i don't see why we couldn't establish a self-sustaining base in Antarctica. Of course, it's forbidden.
Then create one in the Sahara or the Atacana desert at 5000m elevation. Still way easier than Mars.
They are certainly easier, but how useful are they? A base on Mars will bring down the fuel requirements to exploring and exploiting the belt and outer planets tremendously. Missions that are impossible or uneconomical to do from Earth could be made possible and cheap if launched from Mars.
Re: Earth-like planet spotted orbiting Sun’s closest star
#260Earlier quoted context omitted.
Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant. Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a…
> Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Mars might not be sustainable in our lifetime but in a century or two? I think it's within the realm of possibility. As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disa…
> As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disaster.
I mean, you would somehow have to make Earth less hospitable than Mars to make the effort worth it.