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Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

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Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#81

Post by rendall »

moloch-hai wrote: post #50
rendall wrote: post #42

Earlier quoted context omitted.

You're saying that all Earth-sized planets without moons are tidally locked?

All such planets orbiting so close to their star are certainly tidally locked. Even Venus is almost tidally locked, tens of millions of miles away from the sun. All moons in our solar system are locked. It is the norm.

Thanks. TIL.

I have read a science fiction story or two set on tidally locked planets, and the humans occupy the slim twilight belt between the hemispheres facing towards and away from the sun, where the temperatures are less extreme.

If it has an atmosphere, though, I imagine its expansion and compression cycle would make it quite stormy.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#82

Post by enkid »

loxias wrote: post #30
bloaf wrote: post #23

So I thought this would be big news, so I did some reading. Turns out that in like the past 5-6 years we've gone from "who knows how many habitable zone planets there are" to "we're finding them all freaking over the place!" Does anyone have a good blog/news site that covers topics like this? Because evidently I'm missing out.

Over the course of the past 2 decades we've gone from "perhaps some day we'll find extra solar planets" to "most if not all stars have planets". JWST's already found water. At this point it's no longer a matter of if but when extrasolar life will be confirmed, and with which instrument. Might be JWST, might be WFIRST, might be HabEx.

Water is incredibly common in space, so doesn't really prove anything.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#83

Post by exitb »

moloch-hai wrote: post #40

None of these "habitable" planets is really plausibly habitable. In particular, orbiting so close, they are all tidally locked 1:1 to their star, presenting always the same face. If they have any water, it is frozen on the dark side. But they might have no water anyway because they (might!) have no magnetic field to fend off the solar wind that would take away all their hydrogen, as happened to Venus. Earth has its b…

There's probably much more complexity to it, but I wonder if a tidally locked planet could have a habitable ring of mild weather along the terminator.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#84

Post by 867-5309 »

Insanity wrote: post #76
sph wrote: post #59

Earlier quoted context omitted.

Weird popsci analogy. Travel to the nearest star takes a very long time. Michael Jordan can train for thousands of years and will never leave atmosphere with his jump.

Agree it is odd, but I guess they mean through successive jumps always starting from the previous height. (Like jumping up a large staircase).

they obviously didn't, choosing a person with extraordinary jumping ability implies they achieve it in one jump

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#85

Post by 867-5309 »

govg wrote: post #46
skykooler wrote: post #29

Earlier quoted context omitted.

Then we'd better start as early as possible.

There's a funny paradox-like situation that arises in space flight where because of the distances involved/ time taken, it might be better to wait some time for a faster method of flight to develop. Of course, it is up for debate whether there are many more ways of propulsion that are yet to be invented.

incessant obsolescence

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#86

Post by anovikov »

exitb wrote: post #83
moloch-hai wrote: post #40

None of these "habitable" planets is really plausibly habitable. In particular, orbiting so close, they are all tidally locked 1:1 to their star, presenting always the same face. If they have any water, it is frozen on the dark side. But they might have no water anyway because they (might!) have no magnetic field to fend off the solar wind that would take away all their hydrogen, as happened to Venus. Earth has its b…

There's probably much more complexity to it, but I wonder if a tidally locked planet could have a habitable ring of mild weather along the terminator.

Certainly it must have, more than that, it helps widening the definition of habitability as slightly too cold planet must be still habitable further out to the sunny side, and slight too hot one must still be habitable deeper into the twilight zone.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#87

Post by causi »

sammalloy wrote: post #75
loxias wrote: post #71

Earlier quoted context omitted.

I never claimed to have proof, just that it's true. ;-) Personally, it "feels true" that life exists as a undeniable consequence of statistical thermodynamics (see: http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsre... referenced in https://www.quantamagazine.org/a-new-thermodynamics-theory-o... ). But I know I'm an engineer, not a scientist or mathematician. I'm perfectly comfortable with things being true…

I always go back to people like Drake and Shostak. They seem pretty convinced that "they" are out there, but the problem is that there’s no known way to communicate with them due to distance and time. If there’s a way to solve this problem, please let me know. Sagan and others seemed to think that if we could communicate (a very big if), then we could exchange our knowledge, but how exactly could you do that? The pro…

I think we'd better hope that we're alone. If creatures like us are common then that's bad new for us, because "life that behaves like humans and exists for millions of years" and "a galaxy that hasn't been completely filled long before now" are mutually-exclusive states. If we have any chance at all of conquering the stars we'll be doing it alone.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#88

Post by caf »

bryanrasmussen wrote: post #61

If Science Fiction has taught me anything then going to a planet named Wolf {alphanumeric sequence} is a really great idea that won't get most of your crew horribly killed.

Max Wolf catalogued over a thousand high proper motion stars, which tend to be relatively nearby which I guess makes them popular locations for sci-fi.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#89

Post by mcv »

irq wrote: post #63
moloch-hai wrote: post #53

Earlier quoted context omitted.

Mercury and Venus are very near to being tidally locked, despite being thousands of times farther from the sun than the planet cited is from its star. Mars is a good distance off. Earth got its moon via a nearly , but not quite, fatal collision. Probably most other planets did not. Ganymede's magnetic field is news to me. I don't think we know exactly what gives a body a magnetic field, or how it is maintained, but r…

> I don't think we know exactly what gives a body a magnetic field, or how it is maintained, but rotation seems to be important. The magnetic field on Earth is caused by electrical currents flowing in the rotating molten metal of the outer part of our planet’s core. You’re right, rotation is an important factor.

I've long suspected that tidal forces from our moon may be a big factor in keeping the outer core liquid, and thereby keeping our magnetic field active. I have no idea if that's actually true, but if it is, both rotation and a large moon might be requirements for advanced life.

Re: Wolf 1069B: Earth-mass planet in the habitable zone of a nearby, low-mass star

#90

Post by mcv »

sph wrote: post #59
vkou wrote: post #55

Earlier quoted context omitted.

We're likely never to meet or hear from them even if they were a mere 5 light-years. It's easier for Michael Jordan to jump to the Moon, than for man to travel to the nearest star.

Weird popsci analogy. Travel to the nearest star takes a very long time. Michael Jordan can train for thousands of years and will never leave atmosphere with his jump.

And we have gone to the moon, despite it having been impossible for millennia.

And we understand the basic physics of traveling to another star. The only problem is: it's going to take a ridiculous amount of time, and we don't want to do that for a myriad of reasons (money, risk, time), but if we really absolutely wanted to, we could, and there'd be a non-zero chance we'd succeed. Unlike Michael Jordan jumping to the moon.

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