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Though for earthlings info about the project would come far in the future.

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ORIGINAL: BarkellWH

There are so many interesting discoveries being made, and yet to be made, regarding the Cosmos. The W.M. Keck Observatory on Mauna Kea, Hawaii, put out a news release on the findings of some astronomers who have discovered a massive galaxy that consists almost entirely of dark matter. They named it Dragonfly 44, and it has so few "stars" and other "normal matter" that it would fly apart were it not for the dark matter providing the mass.

To quote from the Keck Observatory news release:

"The mass of the galaxy is estimated to be a trillion times the mass of the Sun – very similar to the mass of our own Milky Way galaxy. However, only one hundredth of one percent of that is in the form of stars and "normal" matter; the other 99.99 percent is in the form of dark matter. The Milky Way has more than a hundred times more stars than Dragonfly 44."

The concept of "dark matter" is intriguing. It surely has mass, but it is interesting to speculate what it consists of? Does it have form and shape? Does it have a consistency that can be felt in a tactile fashion? Does it consist of subatomic particles of some sort?

Bill

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ORIGINAL: timoteo

Alpha Centauri has long been a choice for a habitable planet in science fiction. Partly because it's so close, partly because Alpha Centauri A is a G-class sun much like ours. For example, 50 years ago Larry Niven in his Known Space series chose Alpha Centauri as the first human extra-solar colony ('Wunderland'). There are probably earlier examples, that just the one I remember best. So it's not surprising that Avatar made the 'safe' choice of Alpha Centauri. Postulating an earth-like world there is pretty much a no-brainer, since we think that planets are plentiful in the universe, and it's not a great stretch to guess there might be a planet in the goldilocks zone of almost every star. We just don't have the ability to detect them yet.

Proxima Centauri in contrast is a super dim red dwarf (0.2% the brightness of our sun, and all in the red spectrum not in the yellow/green like ours). It would be like having an electric space heater in the sky - warmth but very little light. And red light at that. People would go crazy there. Even here in Seattle people have problems with seasonal affective disorder because we have very short days in the winter. Further north it's a much bigger problem. Imagine living on a planet where daylight is dimmer than the full moon, and the light is always a dark red so you wouldn't see any colors!

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ORIGINAL: Ricardo

A bit off topic but here is something cool about mapping dark matter. The moon is about 30 thousand miles away and another 570 thousand miles out we can find the first concentrations of dark matter that pertains to earth. While we can't detect it on earth sending a sensitive probe out to that distance might turn up results as to whether the stuff is particles or what. https://www.rt.com/usa/323364-dark-matter-earth-hair/

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Oh God you're right, we just might be Proxima Centauri's Mexicans. Probably going to have to pay for that wall over there...

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ORIGINAL: Richard Jernigan

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ORIGINAL: Ricardo

A bit off topic but here is something cool about mapping dark matter. The moon is about 30 thousand miles away and another 570 thousand miles out we can find the first concentrations of dark matter that pertains to earth. While we can't detect it on earth sending a sensitive probe out to that distance might turn up results as to whether the stuff is particles or what. https://www.rt.com/usa/323364-dark-matter-earth-hair/

Sorry, I still haven't gotten over a 43-year career as mathematician, physicist and engineer, but

http://spaceplace.nasa.gov/moon-distance/en/

says he moon ranges between 252,088 and 225,623 miles away in its elliptical orbit around the earth.

RNJ

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Sorry, I still haven't gotten over a 43-year career as mathematician, physicist and engineer, but

http://spaceplace.nasa.gov/moon-distance/en/
says he moon ranges between 252,088 and 225,623 miles away in its elliptical orbit around the earth.

RNJ

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any of these organisms live in complete independence of both solar energy and oxygen. I read recently that they had discovered one particular organism that could produce oxygen using only the glow from the hydrothermal vents. Apparently it is the only known case of photosynthesis using a source other than the Sun. This means that theoretically, other aerobic organisms could develop without the Sun, since oxygen is being produced from a process that doesn't require it. It makes you wonder what could be lurking beneath the ice sheets of Europa, much closer to home than proxima centauri and also completely outside of the so-called habitable zone.