Other Solar Systems: What Are They?

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Discussion Overview

The discussion revolves around the existence and characteristics of other solar systems, particularly focusing on exoplanets and their potential for supporting life. Participants explore various aspects of astronomical observations, imaging techniques, and the implications of discovering habitable planets.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that technically there is only one solar system, referring to the system around our sun, while others discuss known stellar systems and exoplanets.
  • There are claims that most exoplanets resemble Jupiter rather than stars, and direct observation of these planets is challenging.
  • One participant mentions a specific case of a brown dwarf and its imaged planet, highlighting the rarity of such observations and the conditions required for them.
  • Another participant states that several exoplanets have been directly imaged, including some in visible light, but emphasizes that this remains uncommon.
  • Discussion includes the Gliese 581 system, with details about its planets, including a potentially habitable rocky planet, and the methods used to infer its characteristics.
  • Some participants express thoughts on the implications of discovering a habitable planet, including the challenges of interstellar travel and human behavior in such scenarios.
  • There are reflections on humanity's potential actions if a habitable planet is found, with some skepticism about human nature and historical behavior towards new frontiers.
  • Concerns are raised about the conditions necessary for a planet to support life and the limitations of current knowledge in this area.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of exoplanets and the implications of discovering habitable worlds. There is no clear consensus on the specifics of these topics, and multiple competing perspectives are present throughout the discussion.

Contextual Notes

Participants acknowledge the limitations of current observational techniques and the assumptions underlying their claims about exoplanets and the potential for life. The discussion reflects ongoing uncertainties in the field of astronomy.

mreq
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What are the others known solar systems ?
Thanks!
 
Astronomy news on Phys.org
http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm

Technically, there is only one Solar system, as this is derived from Sol, our sun's name. So these are the known stellar systems.:smile:
 
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These planets look like stars!
 
No, they don't - most look like Jupiter. And in any case, we can't see them directly anyway.
 
russ_watters said:
And in any case, we can't see them directly anyway.

Why not?

From the caption:
Biller and her colleagues obtained this image of a very cool brown dwarf orbiting a star near our sun using a camera on the Very Large Telescope in Chile. (Credit: Beth Biller and Laird Close, UA Steward Observatory, 2006)
 

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Wow, I didn't realize that was possible...

Anyway, this article implies that that is the only such photo yet taken and it is only possible because the planet is large and orbiting a brown dwarf at a large distance and both are imaged in infrared. A very unusual case. http://www.eso.org/public/news/eso0511/
 
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In the time since then, a handful of exoplanets have been directly imaged, including in the visible.

Of course, seeing the shadow is even simpler.
 
russ_watters said:
Anyway, this article implies that that is the only such photo yet taken and it is only possible because the planet is large and orbiting a brown dwarf at a large distance and both are imaged in infrared. A very unusual case. http://www.eso.org/public/news/eso0511/

There are a few other photos of other planets, but they are definitely still the exception rather than the rule. The http://www.physorg.com/news185795684.html" was captured with visible light! As with so many things in astronomy, it's only a matter of time. We're taking the most amazing pictures ever, and I can't wait to see how the technology improves.

http://news.nationalgeographic.com/news/2010/06/100630-science-space-planets-first-picture-confirmed/
http://www.nytimes.com/2008/11/14/science/space/14planet.html?fta=y
http://apod.nasa.gov/apod/ap050510.html
 
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  • #10
As i recall 3 planets - out of which one was actually a brown dwarf - has been observed directly so far.
But we will be able to see them very soon; New techniques to substract the stellar glare from exoplanets observations, promises to make it possible for todays Earth based telescopes to see them

See the articles at http://www.spacedog.eu/astronomy/exoplanets/

And with the James Weeb 8m spacetelescope in 2015, the ESO 45m OWL telescope and several others, we will soon also have far more raw resolution power to work with.

But to answer the question:
The Gliese 581-system is a small dwarf-star surrounded by at least 4 planets, out of which 2 are gas-giants and one is an icy planet. But the fourth planet - Gliese581C is a rocky planet5x heavier than Earth, which is covered with a deep ocean!

How do we know this?
Fairly "simple": It has been discovered through the transit method, which allow the astronomers to measure its diameter, based on how much light it's shadow "steals" from the mother-star. Based on the start wobble, it's mass camn be measured.

This has lead to tyhe conclusion, that it has density of 2,5. And since gas is <1, ice is 1 and rock is 4, it has to have a large rocky core, but mixed with plenty of ice, liquid (water, COx or methane) or gas (atmosphere).

Considering that it is in the bio-zone from the star it has been estimated that it has a surface temperature of 0-20'C.

See more on Gliese581 on Wikipedia

/Best regards

Kometkaj
 
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  • #11
If we do finally a detect a habitable planet it will be frustrating for mankind to have to wait until interstellar travel becomes possible in order to visit it. That's it ever does become possible of course.
 
  • #12
Radrook said:
If we do finally a detect a habitable planet it will be frustrating for mankind to have to wait until interstellar travel becomes possible in order to visit it.

it won't be frustrating at all. if a habital planet is ever found, each and every human on Earth will demand vacations there and ALL research will be directed toward reaching it... I PROMISE YOU THAT
 
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  • #13
FawkesCa said:
if a habital planet is ever found, each and every human on Earth will demand vacations there and ALL research will be directed toward reaching it... I PROMISE YOU THAT
If history is any guide a small proportion of people will move there and then spend large amounts of time, money and effort keeping those other aliens out
 
  • #14
mgb_phys said:
If history is any guide a small proportion of people will move there and then spend large amounts of time, money and effort keeping those other aliens out

lets just hope we've evolved better than that...who am i kidding, those aliens are FRAKKING SCREWED
 
  • #15
That's the pity of it all. We take all our foibles with us and that's not good for us nor for others.
 
  • #16
I think there's a lot of conditions to be accomplished for a planet to support life. And i think that we don't know everything of that.
 
  • #17
I doubt we much competion for seeding the galaxy with humanity. Until we find a big sign saying "%& $^*" [eat more embryonic amphibians], the galaxy is our plumb.
 
  • #18
What's a star for us is a sun for them.
Wanna see what an alien looks like?
Look in the mirror.
 

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