Extrasolar Planet Discussion - Now Discussing: KEPLER announces hundreds of candidates

What effect would ripping apart Mercury have? It's mass is enough to construct something like 700,000 to 1,000,000 Halo megastructures(yes, the video game thing). Not sure where to put them. Perhaps in a ring between Earth and Mars orbits or have them orbit along the orbit of Mars.

What would be the point of inhabiting Mercury? Does it have any resources we really need?
Colonising it will be wasteful long term when it is destroyed by The Sun and I think most people would object to living in domes for life.

Relative distance also matters. Earth survives because it exists in the so-called "goldilocks ring". It is far enough away not to be too hot (like Venus) and it is close enough not to be too cold (like Mars). Any further in either direction from the Sun and I don't think Earth would be so great at sustaining life regardless of what atmosphere it has.

Atmosphere is also distance relative. Earth has a good sustained atmosphere due to it's living geological state constantly replenishing it at a high level. It is suitable to protect it from heat and solar radiation at the distance Earth is. Go forward and that shielding may no longer be effective.

Maybe Mercury could develop a stronger protection, but that would be equivalent of using a raincoat to stop floodwater coming in. At that distance it's overwhelming and without a living planet to sustain the atmosphere I can't see it surviving very long.

Venus may well be able to have its atmosphere altered, but it got to the state it is in because it lost it's living state thus rendering its carbon cycle useless so the atmosphere became too dense. Even with algae in the cloud to reduce the levels, how long will that last when the surface will no longer absorb anything? The oceans it is believed to have once had are gone and the hydrogen lost in space. With little or no magnetic field and no plate tectonics I can't see how the planet could restore the life it apparently once had.

Well, I honestly don't understand why you're so forcibly against the idea, considering these are all just fun concepts that have been explored from time to time by various scientists and scientific agencies. Honestly, if the internet existed back in 1492, you'd be admonishing Columbus for wanting to sail across that ocean because it's just water and there's already water where he lives. Sure, but what's beyond the known?

Mercury is filled with precious metals and minerals. Imagine if we developed some sort of energy projector, where solar energy was beamed to earth from collector mirrors on Mercury's surface? But besides that, it's adventurous. I'd bet a lot a people would jump at the chance to be space colonists, I certainly would. Everything being discussed won't even begin for decades, if not a hundred years, so it's not like your taxes are going to go up next week in order to finance a manned mission to Mercury.

The point is that some planets are more suitable for colonization than others, so that's why they're hypothesized. Mercury is one, despite it's proximity to the sun.

Colonies on Mercury would be pretty much the same as colonies on the Moon. I wholeheartedly support the idea, but wouldn't want to spent my life lived in there, never breathing fresh air under an open sky, but living always in closed spaces - even when eventually there could be big closed spaces, if you would take into use old lava tubes etc, and create large-scale gardens in them etc. But I think that beyond basic scientific curiosity the only reason to colonize Mercury would be that there wouldn't be any other better place to colonize in the solar system, or just a need to put humans on every possible place on the solar system. Not that Mercury wouldn't have a bleak kind of beauty in it's landscapes and the best views on the Sun.

When it comes to Venus, it's the same as Mars, it's unlikely to ever be a planet where humans could live outdoors like on Earth, and if it's terraformed, that process have to be kept up, it's unlikely ever to be self-supporting. But you could have more hospitable atmosphere, flowing water on the surface and create gene-engineered flora and fauna that could survive on their surfaces and turn them into living planets. And it's at least 400 million years until Sun would start wreaking havoc, and with really large-scale planetary engineering projects, including changing the orbits of the planets, humanity could perhaps put a one more zero in that number. There would be worse ways for humanity to spend the next billion years or so.

I am so exited about this! What an incredible time we live in. Five hundred years ago people still though the earth was the center of the universe.. Yet, i wish i was born in some 2000 years into the future to see what we had discovered by then. I truly believe we will find life on other worlds soon; maybe not intelligent, but even bacterial life will still be a revolutionary discovery! I wish the government would invest more time & money in space technology and such, but i understand that it cannot be our primary concern with all the troubles we have in our world.

So, it's a bit premature (and certainly loaded) to include this in thread, but does anyone have any thoughts regarding the new form of life -bacteria- that NASA discovered in Mono Lake, CA?

Of course, it's far from being ET, but the bacteria has a cell structure that's based on Arsenic and completely different from anything currently known on Earth. Even if it's a mutant and not an alien, it's still very interesting. I wonder what properties an Arsenic based life form would have, and far off it would be from an episode of Star Trek?

There were internet stories circulating before the announcement that the discovery was an "alien" bacteria which had DNA that substituted arsenic for phosphorus. The truth seems to be a lot more mundane. The bacteria was developed in a lab, not discovered at all, and the bacteria were force-fed increasing levels of arsenic until they *might* have started to incorporate it into their DNA.

The story seems to be: bacteria that live in an environment with a high arsenic concentration can develop a tolerance for arsenic. But still, interesting for its own sake, I guess. Knowing stuff is better than not knowing stuff. Mostly.

I don't know about the first part. The NASA account at least says that one their microbiologists, (specifically a scientist named Felisa Wolfe-Simon) discovered the bacteria in sediments collected from the bottom of Mono Lake ecological area. They isolated the specific bacterium in a lab, but the startling thing was that the bacterium itself developed on its own in the lake bed.

That's a lot more dynamic than just engineering bacteria in a test tube. (assuming that the biologists aren't faking the discovery or anything of that nature.)

The other startling fact of the discovery is that the Mono Lakes themselves are between 8 and 28 million years old, and were formed by the last phases of volcanic activity in the region. Certainly, if extra-terrestial bacteria had fallen to Earth 8 million years ago in a meteorite or similar, and then buried under sediment, they could have sat dormant for all these years. Or even if it's not alien in origin, the time frame matches up for a completely new form of life to have naturally evolved.

Obviously, it would be big news if life turned out to be so common it crops up more than once in the same solar system. Talk about devaluing the coin of the realm!

My sense is, the rarer life is in the universe, the better it is for humans. And that's not just because I've seen all the right movies and read all the right books. As a matter of survival, the last thing we want is to be visited by a species advanced enough to visit us. If it's an arsenic DNA bacteria hitching a ride on space debris, maybe that's ok. But I've also seen the Andromeda Strain, the first one, the good one, and that was very unsettling.

I don't get what the fuss is about. The universe is mostly made up of hydrogen, oxygen, and carbon. All known life is mostly made up of hydrogen, oxygen, and carbon. So if there's other life out there, wouldn't it be more likely to be made up out of one of those three elements, rather than some obscure element?

Sure, maybe this widens the scope, but only by a measly bit.

But Watto, don't you think any discovery of new life should warrant some fuss? Even if it just widens the known life form scope a measly bit, it's a bit that we didn't know about before.

Even if it's just alien bacteria, the thought of other life is a big deal. But of course the extra-terrestrial claims are all just fun conjecture. I doubt that the bacteria is going to hypergrow into a giant monster, or is a prelude to an alien invasion. But the fact is that there is bacteria sitting at a bottom of 20 billion year old lake that was able to adapt its DNA to incorporate Arsenic. That's pretty cool in its own right, and may give insight into how other bacteria becomes resistant to penicillin, and such.

Just want to point out that the exoplanet database app for the iPad is hours and hours of relentless entertainment. I'm not kidding.

buy an iPad just for this. Seriously.

Obviously, it would be big news if life turned out to be so common it crops up more than once in the same solar system. Talk about devaluing the coin of the realm!

I thought that was established years ago with the fossil discoveries on Mars. I thought they'd seen evidence of microbial life along with the evidence of water.

In any case, I think life itself is a lot more common than has been previously thought. Since the 80s I believe it has been proven that you can create life in a vacuum from non-living materials. It would seem the necessary components might have more to do with a planet's distnace from its Sun than most other factors.

Given that, extraterrestrial life in whatever form is probably a foregone conclusion. Evolved life somewhere out there is probably very, very likely.

Inelligent life on the order of human beings would probably still be extremely rare to non-existant -- and if it did exist we'd probably never meet it since interstellar travel seems at this point less likely than existant extraterrestrial societies -- but I think we're starting to see that if we're alone in the universe, it's not for the lack of life in it.

One of the nice things about the exoplanet app is how it relates the orbits of the newly discovered planets to their solar systems' habitable zones, however that's defined.

The details are riveting, but in general it's fascinating to see the big picture forming of the extent to which so many of the stars we see have planets orbiting around them. I'm more convinced than ever there is life elsewhere in our galaxy. Thank the heavens for large, heavenly distances.

Ok really, this is simply Earth size and that's all there is to it. 1.4? I mean would they actually say that if it were .9 X Earth that it would not be detected? I'd make a Go Science thing on this but it'd die. There is an astronomy thread though.

I wish I had an extra billion or two to donate to a massive telescope project.

very exciting news. Within years maybe we'll get some very reasonable calculations of the potential number of earth-sized exoplanets within their stars' habitable zones. Kepler still seems like pure science fiction to me - the possibility that habitable planets are only a few hundred light years away.

Here's hoping that if there is life out there, it's very, very far away.

[image=http://aether.lbl.gov/www/classes/p139/speed/planets.gif]

A diagram of our nearest stars and their habitable zones. It is my understanding that the Alpha A&B stars are just too bright right now for our technology to detect a world in the habitable zones for stars that are so close. Irony.

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