Also it depends if it's a lone object or if it has a large moon or moons. A Super-Earth could conceivably have a large habitable moon.RJDiogenes wrote: ↑Wed Feb 10, 2021 11:51 pmWell, not necessarily habitable by us.Now "potentially habitable" should probably be taken with a grain a salt as the planet might be the size of Neptune- making it a super-Earth at best.But I wonder what its actual surface gravity is-- the larger the planet, the farther the surface is from the center of gravity. It would really depend on the mass what the thing is actually made of.
Science Tidbits #6
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Re: Science Tidbits #6
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True. A large moon could also possibly throw off the data, making the planet look bigger than it is.
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And here on Earth, it looks like Stonehenge might have been moved at some point in the distant past.
You might say it became unhenged.
You might say it became unhenged.
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That's remarkable. Moving that thing is as great a feat as building it to begin with.
They should have used that for the documentary.You might say it became unhenged.

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^ That Stonehenge finding is remarkable. Maddie only lives about an hour's drive from the current location.

Good one, Lupy

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^That's been part of a "Plan B" for some time, though this is the first I've heard of any real plans.
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Interesting. It strikes me as a possible "old lady who swallowed the fly" scenario, but it could work. At the very least, it will be fun to watch the contrail conspiracists go nuts. 
There was a similar plan, I think, to work it from the other end by putting certain metals in the ocean (in a controlled fashion) that would absorb carbon dioxide, but I'm not sure where they are with that.
I kind of like the idea of flying an adjustable screen out to L1 that could reduce the amount of solar radiation slightly to reduce warming. It seems like the most easily controllable possibility.

There was a similar plan, I think, to work it from the other end by putting certain metals in the ocean (in a controlled fashion) that would absorb carbon dioxide, but I'm not sure where they are with that.
I kind of like the idea of flying an adjustable screen out to L1 that could reduce the amount of solar radiation slightly to reduce warming. It seems like the most easily controllable possibility.
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Hmmm. What is L1 and how would this work?RJDiogenes wrote: ↑Wed Mar 03, 2021 11:20 pmI kind of like the idea of flying an adjustable screen out to L1

Re: Science Tidbits #6
^It's one of the Lagrange Points in Earth's orbit. The screen would be positioned between Earth and the sun, cutting down the heat we receive and cooling the Earth. It does sound like the best bet as it can be quickly reversed unlike the other options being discussed.
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^That's really cool. How big a screen are we talking about?
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Also, it could be adjustable, like a giant Venetian blind.Lupine wrote: ↑Sat Mar 06, 2021 3:55 pm^It's one of the Lagrange Points in Earth's orbit. The screen would be positioned between Earth and the sun, cutting down the heat we receive and cooling the Earth. It does sound like the best bet as it can be quickly reversed unlike the other options being discussed.
Miles, but that's not as bad as it sounds. The screen itself would be as insubstantial as a solar sail, and because the shadow would spread with distance it would be relatively small compared to the size of Earth (and even the shadow wouldn't have to encompass the entire hemisphere-- just enough to reduce the sunlight a percentage point or two).
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That's really fascinating. Is this really feasible? Wouldn't all countries of the earth have to agree to have this done?RJDiogenes wrote: ↑Sat Mar 06, 2021 11:42 pmMiles, but that's not as bad as it sounds. The screen itself would be as insubstantial as a solar sail, and because the shadow would spread with distance it would be relatively small compared to the size of Earth (and even the shadow wouldn't have to encompass the entire hemisphere-- just enough to reduce the sunlight a percentage point or two).
And on a different topic, here's a cool observation:
"To compare the relative physical scale of the Milky Way, if the Solar System out to Neptune were the size of a US quarter (24.3 mm (0.955 in)), the Milky Way would be approximately the size of the contiguous United States."
Re: Science Tidbits #6
It's feasible though so expensive that it would have to be an international effort- and it wouldn't necessarily have to be a solid structure. A series of hundreds or thousands of satellites could be used.scottydog wrote: ↑Sun Mar 07, 2021 1:36 amThat's really fascinating. Is this really feasible? Wouldn't all countries of the earth have to agree to have this done?RJDiogenes wrote: ↑Sat Mar 06, 2021 11:42 pmMiles, but that's not as bad as it sounds. The screen itself would be as insubstantial as a solar sail, and because the shadow would spread with distance it would be relatively small compared to the size of Earth (and even the shadow wouldn't have to encompass the entire hemisphere-- just enough to reduce the sunlight a percentage point or two).
I've heard comparisons like that before and they really illustration the scale of things. If I remember correctly on that same scale Alpha Centauri would be 3 miles away.scottydog wrote: ↑Sun Mar 07, 2021 1:36 amAnd on a different topic, here's a cool observation:
"To compare the relative physical scale of the Milky Way, if the Solar System out to Neptune were the size of a US quarter (24.3 mm (0.955 in)), the Milky Way would be approximately the size of the contiguous United States."
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Actually, I'm not sure if the Outer Space Treaty even addresses anything beyond Earth orbit (there's a separate treaty for the Moon), but given that it's something that would affect the entire planet (and would require, as Lupy says, an international effort to build), I'm sure the UN would be involved.
Indeed. Space is immense. Which is one of the reasons I think interstellar travel is very rare."To compare the relative physical scale of the Milky Way, if the Solar System out to Neptune were the size of a US quarter (24.3 mm (0.955 in)), the Milky Way would be approximately the size of the contiguous United States."
That's a good point. Construction would be just as complicated, but maintenance probably a lot easier.
Re: Science Tidbits #6
An interesting article on whether we should seed life on alien worlds.
Personally I'm not against it. Sure, you would have to be absolutely certain that no indigenous life exists there. But as the article points out it would be highly instructive on where life can actually proliferate and how it changes its environments. And if my some chance life in the universe is rare or nearly unheard of, we should take steps to make sure it continues if something were to happen to Earth.
Personally I'm not against it. Sure, you would have to be absolutely certain that no indigenous life exists there. But as the article points out it would be highly instructive on where life can actually proliferate and how it changes its environments. And if my some chance life in the universe is rare or nearly unheard of, we should take steps to make sure it continues if something were to happen to Earth.
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I laughed when they mentioned Genesis. The first thing I thought of when I read your post was Chekov saying, "Does it have to be completely lifeless?" 
It's an interesting question, certainly, but the impracticality of it probably makes it moot. Any experiments would have to be limited to our Solar System because of the pesky size of the Universe, and even then they're talking about experiments thousands of years in duration. Plus, I suspect that any place where life is possible will already have it-- although it's not impossible that life could be successfully introduced into places where it is not possible on its own. I'm kind of rooting for those little tardigrades on the Moon and I'm more optimistic than the guy in the article. It also makes me think that any experiments along these lines will probably be accidental.

It's an interesting question, certainly, but the impracticality of it probably makes it moot. Any experiments would have to be limited to our Solar System because of the pesky size of the Universe, and even then they're talking about experiments thousands of years in duration. Plus, I suspect that any place where life is possible will already have it-- although it's not impossible that life could be successfully introduced into places where it is not possible on its own. I'm kind of rooting for those little tardigrades on the Moon and I'm more optimistic than the guy in the article. It also makes me think that any experiments along these lines will probably be accidental.

Re: Science Tidbits #6
^Probably already have- considering some bacteria have almost certainly already arrived on Mars.
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That's true. And we've been poking deeper and deeper holes in the ground, so who knows?
The itinerary for the first year of the Webb Scope has been released. I haven't looked at the whole thing, but there's some pretty groovy stuff going on in the Exoplanet category. The next couple of years could be pretty amazing.
The itinerary for the first year of the Webb Scope has been released. I haven't looked at the whole thing, but there's some pretty groovy stuff going on in the Exoplanet category. The next couple of years could be pretty amazing.
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^That's a busy scheduled they got laid out. Weirdly though I couldn't find any missions that are specifically looking for oxygen on exo-planets. You'd think that would be among the top priorities. Though 2589 will be looking at the atmospheres of the TRAPPIST planets, so there's hope there.
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Yeah, I saw a few spectroscopy items. Maybe they granted them based on the likelihood of success.