16 exoplanets found huddled around 12 lightweight stars A team of astronomers have spotted 16 exoplanets, including a ‘super-Earth’ that might hold liquid water, hovering around 12 low mass stars hundreds of light years away from the Solar System. One of the most luminous red dwarf stars, codenamed K2-155, in the dozen is of particular interest. Located about 200 light years away, …
I wonder how long until it's discovered that the dynamically variable seashore environment caused by tides are a critical part of life's eventual rise to intelligence. A similar point might be made for seasonal temperature extremes caused by a tilted axis. It'd be funny if both (the Moon and the Earth's tilted axis) were caused by the very same collision.
Perhaps boring planets only have green goo.
Never been too hot on the "tidal requirement" argument when it comes to "advancing life". Even when the Moon was a lot closer to us, and tides were .. a bit more pronounced.
Thing is, life over here progressed from Green Goo up to Fishes, Crustaceans, and Other Stuff well away from any tidal zones, in the ocean. The fossil record is clear enough about that. So really.. Moon Not Needed.
I think the metal content of the stars is more significant. More metal = more chance on a viable metallic core = a solid magnetic field. Which is the first buffer a planet, and anything living on it, has against several shades of Nastyness happening to it. The way Mars lost its water and atmosphere to solar wind shows what happens if that magnetic field fails..
I think the list of variables that give rise to complex life might wind up being quite long and include such things as a decent sized gas giant (or two) to catch incoming rocks also.
Although everywhere we look on Earth we find life, so maybe life is really adaptable and can arise in almost any circumstance.
We won't really know until we go and have a look.
Tides, metallic core etc etc ineresting to discuss as to how it affevted evolution of intelligent life, but what might be more interesting is, what components are needed to support human life of a human race with the technology for interstellar travel.
I guess rocky and having at least some zone with temperature 0-30 degrees with only minor variations. Beyond that? a human race capable of interstellar travel would surely be able to set up some protective domes with controlled atmosphere and radiation filtering, and with sufficient energy (dare I hope that controlled fusion will be cracked in a few hundred years, if we survive that long), comets / other space junk can be harveted for water and minerals, crops can be grown hydroponically etc etc.
For interplanetary travel, it's already quite well studied / established what might be required to support human life on Mars. In effect the biggest obstacle is heavy launch capacity from Earth's gravity well, and the gigantic associated costs. We already have most of the required technology, it just needs refining / minitiarising / commoditising to be reliably usable on a large scale (which again is limited by cost).
I think the metal content of the stars is more significant. More metal = more chance on a viable metallic core = a solid magnetic field
That's a nice theory, except that when astronomers and astrophysicists talk about the metal content of stars, they mean any element that isn't hydrogen or helium. Yes, that means that oxygen and nitrogen are, in stellar composition terminology, metals.
The thing about tides is, you don't need a moon for them. The sun also causes tides. Not as much as our moon's tides, but enough to make a difference between spring and neap tides (or swede tides, if you're Scottish). Which is a good thing, because our moon is abnormally large and it's likely to be very rare for a planet to have a moon that large. Yes, there are larger moons in our own solar system, but not as large as ours relative to the planets they orbit.
I doubt seasonal temperature variations speed up the evolution of multicellular or even intelligent life. But I could be wrong about that.
It's possible you need a molten core for life. One hypothesis for abiogenesis is the convection currents and supplies of chemicals around hydrothermal vents being ideal for polymerizing nucleotides. Those vents tend to have a lot of archaean extremophiles, and archaea predate bacteria.
The magnetic field associated with a molten core also seems important to shield the planet from harmful radiation.
send a probe, someone has finally worked out how to make my perpetual generator to replace the blades on wind turbines and have a constant 10MW every hour https://www.youtube.com/watch?v=KkV8QGU1UV4
no someone other then BAE Systems needs to workout my EM Drive, but someone is close to that too https://youtu.be/6gszIwmpsO0?t=1m16s
Not even that.
Voyager took decades to get to Jupiter.
Just getting a system that could get a serious fraction of light speed would be big start.
So far this looks at various "laser launch" ideas and the "fission fragment rocket." Turns out the fission fragments from a nuclear reactor (normally trapped inside the Uranium Oxide pellets) are moving at about 5-10% of the speed of light. Very tricky engineering, but no new physics needed.
The problem is that even at light-speed, it's 200 years away. And when you get there (if you get there), it'll likely be most dull and you won't be able to tell anyone who cares for another 200 years.
Not only does it need to be FTL, but significantly so... maybe twice as fast. And even then you're 200 years from finding out and telling anyone. In that 200 years, you'll almost certainly be overtaken by something that'll do a better job. Imagine that - 199 years in transit, generations cooped up on a ship, and then all of a suddenly "Whoosh," and Flash Lockhart appears... "WWWAaaaahhhaahhhey! What're you guys still doing here?! Jump on and I'll give you a lift! We colonised that planet last century... by now about 99% of them have my DNA in them.... WOOF!".
To say you'd be slightly irritated at the waste of time, effort and money involved would be understating it a little.
We not only need FTL, but FTL comms, and to know that in the time we get there, nobody's going to overtake us. Who's going invest in a dead-end that 20 years later will be overtaken by its competitor and become worthless? Maybe the first one, but after that?
Voyager took decades to get to Jupiter.
Voyager 1: Launch: September 5, 1977, Jupiter closest approach: March 5, 1979: flight duration 18 months.
Voyager 2: Launch: August 20, 1977, Jupiter closest approach: July 9, 1979, flight duration 23 months.
So, yes, it was decades. 0.15 decades for one of them, 0.19+ decades for the other.
my EM Drive will blast a craft off at 256 million MPH in 0.5 seconds, if you base the spec's and repelling forces on BAE Systems railgun, and just multiply them by 1000, you have a 100 ton shuttle
256 million MPH is as fast and human tech can go, or the craft will out run, radar signals for navigation systems etc
the basis' of everything for the MoD's black project of skylon 8 is in https://forums.theregister.co.uk/forum/2/2017/07/27/nasa_lights_bloody_big_rocket_that_doesnt_go_anywhere/#c_3245239
the deciding factor on why britain is really getting space plane ports
What is the point of getting excited about this, apart from the soapbox of pure science, when you have no, even theoretically, viable means of reaching them is anything like a reasonable time? No way of supporting any enterprises set up to exploit the resources available if you managed to get there in one piece.
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