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World & Current Events > Star system has record eight exoplanets

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message 1: by Quantum (last edited Dec 15, 2017 05:38PM) (new)

Quantum (quantumkatana) Star system has record eight exoplanets - BBC News
http://www.bbc.com/news/science-envir...


message 2: by Matthew (new)

Matthew Williams (houseofwilliams) Okay, new record! First TRAPPIST-1, now this!


message 3: by Quantum (last edited Dec 15, 2017 08:53PM) (new)

Quantum (quantumkatana) Here's Kepler-90



but Trappist-1 is much closer:



https://en.wikipedia.org/wiki/TRAPPIST-1


message 4: by Matthew (new)

Matthew Williams (houseofwilliams) And so is this!

description


message 5: by [deleted user] (new)

Guys, I have no doubt that there are thousands, millions even of habitable exoplanets in this galaxy alone. However, we still have to get to them, or someone else to get to us from them. Yes, we can certainly write tons of sf novels about them and imagine what could happen one day.


message 6: by Graeme (new)

Graeme Rodaughan My POV is that life is hard coded into the laws of this universe and will occur where it can.

Lot's of planets implies lots of life.

Very occasionally intelligent life capable of creating technology will arise.

Some of those species will manage to space fare.

The universe is still very young.

I don't think we have been visited yet, but you never know what the deep future holds.


message 7: by Matthew (new)

Matthew Williams (houseofwilliams) Michel wrote: "Guys, I have no doubt that there are thousands, millions even of habitable exoplanets in this galaxy alone. However, we still have to get to them, or someone else to get to us from them. Yes, we ca..."

There are roughly 100 billion planets in our galaxy, according to the most recent estimates. As for habitable, that remains debatable. As for "transiently habitable" and willing and able to be seeded with life? Somewhat less debatable!


message 8: by Matthew (new)

Matthew Williams (houseofwilliams) Graeme wrote: "My POV is that life is hard coded into the laws of this universe and will occur where it can.

Lot's of planets implies lots of life.

Very occasionally intelligent life capable of creating technol..."


Are you saying humanity is early to the party? If so, you are not in bad company!


message 9: by Graeme (new)

Graeme Rodaughan Yes. Thanks.


message 10: by Matthew (new)

Matthew Williams (houseofwilliams) And here's the interesting part. First, you got recent surveys that have found a plethora or rocky planets around red dwarf stars, and then studies that have indicated that said types of planets are more likely around these types of stars.

When you consider how long it takes life to emerge (4 billion years before complex organisms emerged on Earth), stars with natural longevity become the more likely places to find it. Considering that red dwarf stars have lifespans of up to 10 trillion years, but take longer to become stable, and it suddenly seems like life in the cosmos might be in its infancy right now.


message 11: by [deleted user] (last edited Dec 16, 2017 07:28AM) (new)

But, will the laws of universal physics keep all intelligent life prisoner of their home solar system forever, due to the limit of light speed? In our own case, I certainly see us be able to travel routinely through our own solar system before the end of the 21st Century (if we don't blow ourselves up first or get washed out by rising seas), but finding a way around the limit of light speed is a lot more questionable, even if we keep 'inventing' ways in our sci-fi books.

The one thing that may realistically get us into contact with alien intelligence (forget flying saucers, secret aliens visiting our past, abductions by aliens, etc.) is radio-astronomy. We already have the means to listen to messages from other solar systems and could quickly build powerful radio communication stations if a genuine alien signal is ever picked up. That, in my mind, is a lot more realistic and probable scenario than inventing some kind of 'warp drive'.


message 12: by Ian (new)

Ian Miller | 1857 comments I am not convinced that many of the planets are rocky. As I recall it, the densities of the Trappist 1 system were calculated, and none of them exceeded 2. A rocky planet like Mars has a density of about 3.8, Earth about 5.5 (from memory). The reason is basaltic silicates have a density >3, and if the iron separates to a core, that lives the density. The density also grows a bit due to compression from gravity, so in my opinion, most of those systems around red dwarfs will be water worlds (or icy planets until they get big enough to hold a lot of gas).

My mechanism of planetary formation requires the stellar disk to reach temperature of about 1200 C to make rocks, and that will not happen around a red dwarf until it gets almost too close to be free, although I suppose tidal interactions could send such a planet out a bit. However, I am not very enthusiastic about the prospects for life around red dwarfs. Basically, in the regions where the planets are, it never got hot enough to make the chemicals necessary to form life independent of a water world, and a water world would probably have great difficulty in getting enough phosphate to the surface. (In the presence of divalent metals, phosphates are insoluble in water. If there are no divalent metals, you can't make many of the catalysts life uses.)


message 13: by Quantum (last edited Dec 16, 2017 05:17PM) (new)

Quantum (quantumkatana) Ah, thought-provoking analysis. Then Kepler-90 seems more likely to host viable candidates.
Because the new world, dubbed Kepler-90i, is so much further in - it completes one circuit of its star every 14.4 days - it's estimated to have a scorching hot surface temperature of around 425C.



message 14: by Ian (new)

Ian Miller | 1857 comments Sounds hellish - more or less like Venus. I think I shall turn down a ticket to go there and stay right here.


message 15: by Quantum (new)

Quantum (quantumkatana) Ha!


message 16: by Matthew (last edited Dec 16, 2017 07:23PM) (new)

Matthew Williams (houseofwilliams) Ian wrote: "I am not convinced that many of the planets are rocky. As I recall it, the densities of the Trappist 1 system were calculated, and none of them exceeded 2. A rocky planet like Mars has a density of..."

Not from what I'm seeing here. Between b and g, the densities range from 3.3 at the lower end to over 6.54 g/cm3. The only one that isn't known is h.

http://www.trappist.one/#system


message 17: by Ian (new)

Ian Miller | 1857 comments Matthew, you are right. I must have had a memory lapse or the figures have changed. Planet c is almost certainly rocky. Some of the others I think it is still open, thus 0.66 +/- 0.56 is still open a the error rang is almost as large as the datum. But c would seem to be rocky.


message 18: by Matthew (new)

Matthew Williams (houseofwilliams) They probably changed. You know how it is, they do multiple surveys, and the estimates get more accurate over time with more data. However, I do doubt that any of these are habitable worlds. The research has been very downer-y when it comes to red dwarf habitability.


message 19: by Nik (last edited Dec 17, 2017 12:17AM) (new)

Nik Krasno | 19865 comments Alex wrote: "Star system has record eight exoplanets - BBC News
http://www.bbc.com/news/science-envir..."


I can smell a possible cheap labor resource for our industrialists -:)
First expedition will consist of sales agents and recruitment officers


message 20: by Ian (new)

Ian Miller | 1857 comments I hope you realize, Nik, that the light output of a red dwarf is mainly in the infrared, so the ability to do photochemistry and grow plants might be a little on the sluggish side. Your "cheap labour" might be somewhat undernourished, and thus sluggish workers. 😞


message 21: by Nik (new)

Nik Krasno | 19865 comments Ian wrote: "Your "cheap labour" might be somewhat undernourished, and thus sluggish workers. 😞..."

Isn't the doctrine to keep workers a little hungry? -:) Well nourished ones might be a little sleepy, hence - higher premiums for work safety insurances, etc


message 22: by Ian (new)

Ian Miller | 1857 comments I can see you are a hard boss, Nik.


message 23: by Nik (new)

Nik Krasno | 19865 comments Ian wrote: "I can see you are a hard boss, Nik."

Me? No. Just know the theory, but have hardships in implementation -:)


message 24: by [deleted user] (last edited Dec 17, 2017 05:36AM) (new)

Well, as long as somebody doesn't decide to use some of those hellish worlds as prison planets. Imagine: space gulags!


message 25: by Nik (new)

Nik Krasno | 19865 comments Michel wrote: "Imagine: space gulags!"

-:)


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