Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Random thought: Percentage of stars similar enough to our sun to allow for planetary life?

  • Please log in to reply
19 replies to this topic

#1 Ballyhoo

Ballyhoo

    Gemini

  • *****
  • topic starter
  • Posts: 3315
  • Joined: 22 Jul 2011
  • Loc: San Diego

Posted 25 June 2019 - 04:25 PM

I would think that in order for planets to allow life (as we understand per biology, physics etc), the first thing is that the star cannot fry everything nearby, Then the mass of the sun must be the right amount to allow planetary gravity of the right amount. Now then if a star is much more massive, perhaps it being further away from a planet will offset the mass. edit. But, are there a lot of planets out there like our sun?      There are a lot of stars out there similar to our planet.


Edited by Ballyhoo, 25 June 2019 - 05:26 PM.


#2 bobito

bobito

    Surveyor 1

  • *****
  • Posts: 1583
  • Joined: 15 Aug 2014
  • Loc: Litchfield County, CT

Posted 25 June 2019 - 04:43 PM

About 10% of stars are like our sun. 

But, as you surmised, a star doesn't have to be like our Sun to support life.  There could be life that requires large amounts of radiation to survive, they would see our Sun as not able to support life.


Edited by bobito, 25 June 2019 - 04:43 PM.


#3 Dynan

Dynan

    Mercury-Atlas

  • *****
  • Posts: 2719
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 25 June 2019 - 04:51 PM

"But, are there a lot of planets out there like our sun?"

 

No. There are NO planets like our Sun.

 

"Percentage of stars similar enough to our sun to allow for planetary life?"

 

Douglass Adams gave us the answer to every existential question...in this case 42%.



#4 Stellar1

Stellar1

    Mariner 2

  • -----
  • Posts: 285
  • Joined: 08 Dec 2018
  • Loc: Ontario, Canada

Posted 25 June 2019 - 05:07 PM

As mentioned above, a star doesn't have to be like our sun in order to allow for "A" planet or some of its planets to fall within the habitable zone. Imagine two stars, both 5 times the mass of our sun, one may have a planet which orbits too close and therefore too hot for life to evolve, the seconds star may well have a planet or planets which orbit at just the right distance (habitable zone). There are many variables to consider when tackling this question, I'm not so sure the type of star is as important as its planets and, their distance and what matter they are composed of.



#5 Ballyhoo

Ballyhoo

    Gemini

  • *****
  • topic starter
  • Posts: 3315
  • Joined: 22 Jul 2011
  • Loc: San Diego

Posted 25 June 2019 - 05:27 PM

As mentioned above, a star doesn't have to be like our sun in order to allow for "A" planet or some of its planets to fall within the habitable zone. Imagine two stars, both 5 times the mass of our sun, one may have a planet which orbits too close and therefore too hot for life to evolve, the seconds star may well have a planet or planets which orbit at just the right distance (habitable zone). There are many variables to consider when tackling this question, I'm not so sure the type of star is as important as its planets and, their distance and what matter they are composed of.

well in that case there may be a few trillion planets out there supporting life, from one corner of the universe to the other.   And perhaps there are as many unvierses out there as galaxies . But as far as we know, the big bang only involved our universe.



#6 Conaxian

Conaxian

    Ranger 4

  • *****
  • Posts: 354
  • Joined: 06 Oct 2018
  • Loc: Smalltown, South western Ohio

Posted 25 June 2019 - 05:37 PM

For advanced life to develop there is one factor that is very important.  The star has to be stable.  There are stars that have variable or erratic energy output or even go nova from time to time.

We are here because we have a very stable sun that's old and trustworthy, x flares, solar maxes and minimums notwithstanding.

 

I've read that the very hot blue/white stars are young and full of mischief. There is not much chance of complex life being found on their planets.



#7 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 77241
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 25 June 2019 - 05:38 PM

It all supposition, hypothetical..  we really don't know what constitutes a habitable zone.. 

 

There maybe untold numbers of life bearing planets or there may be only one. My guess is untold numbers but that we will never truly know if there's even one beyond our solar system.

 

Jon


  • havasman likes this

#8 ascii

ascii

    Surveyor 1

  • -----
  • Posts: 1696
  • Joined: 04 Jun 2016
  • Loc: Orlando, FL, USA Approximately 28.5ºN,81.5ºW

Posted 25 June 2019 - 06:11 PM

The conjecture that I've heard is that there may only be certain spectral types of stars that are conducive to having planets with "life as we know it."  Obviously, G-type stars, like our sun, is one.  Slightly cooler orange K-type stars maybe even more conducive to life.  M-type stars flare too much, and F-type and hotter emit so much harsh radiation and/or have such short lifespans that they are less likely to have planets with life.  Again, this is conjecture from some scientists.



#9 mistateo

mistateo

    Apollo

  • *****
  • Posts: 1234
  • Joined: 02 Feb 2017
  • Loc: San Diego, CA

Posted 25 June 2019 - 06:14 PM

There is a flaw in determining the "habitable zone."  In OUR definition, it means the planet is located at a distance from it's host star such that liquid water can exist on the surface.  Other life forms may potentially use a different medium (other than water) to base life around.  The other issue is that HUMAN like forms (carbon based water dependents that are radiation sensitive) would likely not evolve around blue stars (lifespan too short) or red dwarf stars (prone to violent solar flares, much worse than our sun).  So in short, we make a lot of assumptions on what constitutes "intelligent life."



#10 MikeHC8

MikeHC8

    Sputnik

  • -----
  • Posts: 47
  • Joined: 09 Dec 2018
  • Loc: San Diego

Posted 25 June 2019 - 06:56 PM

I would like to know how many planets like ours have been wipe out and started all over again.  I had the privilege to work with temperature scientist who took to his last breath that we are the 2nd set of humans on earth, we were wipe out once before.  I always like other peoples  ideals.  I feel that there is much more life out there then we can ever understand, I would just like it proven 100%.     



#11 Ballyhoo

Ballyhoo

    Gemini

  • *****
  • topic starter
  • Posts: 3315
  • Joined: 22 Jul 2011
  • Loc: San Diego

Posted 25 June 2019 - 07:52 PM

I do not think people like to deal with the issue of kinetic energy and how that would affect other life forms. Human beings and the millions of other life forms on earth exist because all of the right conditions occurred. What we know about biology of cellular growth is very adversely susceptible kinetic energy (or too much thereof). So I think life exists where the kinetic energy and radiation is suitable for cellular growth; DNA/RNA synthesis, etc..  But that is just me.  I do not think there is life where the kinetic energy is much lower or higher than ours here. What dos a lot of kinetic energy do? It melts things.  So, the only thing then could be lava monsters, but even then I do not buy into that. Edit, and lower kinetic energy, as we go toward zero kelvin, there is stasis.


Edited by Ballyhoo, 25 June 2019 - 07:56 PM.


#12 Billy Bl.

Billy Bl.

    Mariner 2

  • -----
  • Posts: 209
  • Joined: 26 May 2007
  • Loc: North of 49

Posted 26 June 2019 - 07:19 AM

There is a flaw in determining the "habitable zone."  In OUR definition, it means the planet is located at a distance from it's host star such that liquid water can exist on the surface.  Other life forms may potentially use a different medium (other than water) to base life around.  The other issue is that HUMAN like forms (carbon based water dependents that are radiation sensitive) would likely not evolve around blue stars (lifespan too short) or red dwarf stars (prone to violent solar flares, much worse than our sun).  So in short, we make a lot of assumptions on what constitutes "intelligent life."

Perhaps, but chemistry has the final say. Life is the organised flow of electrons and protons, with "organised" (i.e. not just ordered) being the key word. Water and carbon have unique properties that life on Earth depend on.


  • Dynan likes this

#13 Waddensky

Waddensky

    Mariner 2

  • -----
  • Vendors
  • Posts: 208
  • Joined: 18 Sep 2017
  • Loc: The Netherlands

Posted 26 June 2019 - 08:03 AM

Wikipedia has an interesting annotated list of stars similar to the Sun. Still, as others have said, that doesn't imply they support life nor that other stars can't. But I like the notion of similarity when I observe one - the idea that our Sun looks like that from that distance.



#14 epee

epee

    Gemini

  • *****
  • Posts: 3291
  • Joined: 30 Nov 2006
  • Loc: Suh-van-nuh, Jaw-juh

Posted 26 June 2019 - 08:09 AM

To develop complex life, the only planet we know of to do so features the following:

 

  1. A very circular, low eccentricity orbit.
  2. A long-lived, but bright dwarf star.
  3. A large Moon, generating a large tidal zone around the oceans
  4. A solar system with large -body orbits stable over billions of years 

1 & 4 are likely related. However, those qualities seem to discourage the likelihood of 3.


  • jaraxx likes this

#15 Ballyhoo

Ballyhoo

    Gemini

  • *****
  • topic starter
  • Posts: 3315
  • Joined: 22 Jul 2011
  • Loc: San Diego

Posted 26 June 2019 - 01:11 PM

To develop complex life, the only planet we know of to do so features the following:

 

  1. A very circular, low eccentricity orbit.
  2. A long-lived, but bright dwarf star.
  3. A large Moon, generating a large tidal zone around the oceans
  4. A solar system with large -body orbits stable over billions of years 

1 & 4 are likely related. However, those qualities seem to discourage the likelihood of 3.

These reasons are also why I feel that the habitable zone we live in is much more unique than people give it credit for.  I am not sure the universe is swarming with like like people think, ut I do fee that there have to be other habitable zones out there, however few or numbered.



#16 dgordontx

dgordontx

    Vostok 1

  • -----
  • Posts: 164
  • Joined: 08 Jan 2018
  • Loc: Central, TX

Posted 26 June 2019 - 01:34 PM

Life in general? All of them.

 

A kangaroo rat doesn't need any water in it's entire life. Olms can go 10 years without food. The larvae of a red flat bark beetle doesn't freeze even at -148 F. The sahara desert ant survives at 122 F. The water bear can survive  range of -459 F to 302 F. All according to Nat Geo anyway. Those same water bears can also stand radiation almost 1000x greater than a human can.


  • Dynan likes this

#17 Dynan

Dynan

    Mercury-Atlas

  • *****
  • Posts: 2719
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 26 June 2019 - 04:17 PM

The water bear can survive  range of -459 F to 302 F. All according to Nat Geo anyway. Those same water bears can also stand radiation almost 1000x greater than a human can.

Tardigrades! So sturdy because they know...SCIENCE!


  • payner likes this

#18 chicagorandy

chicagorandy

    Sputnik

  • -----
  • Posts: 41
  • Joined: 12 Jun 2019
  • Loc: Chicago, IL USA

Posted 26 June 2019 - 04:34 PM

I promise to concern myself over intelligent life on other planets the day after it is discovered on this one.


  • dgordontx likes this

#19 sec4aa

sec4aa

    Vostok 1

  • -----
  • Posts: 141
  • Joined: 17 May 2017
  • Loc: Long Island, NY

Posted 26 June 2019 - 06:57 PM

Interesting topic...What come into mind is Drake equation and Fermi paradox.

I do think that there are many intelligent civilizations out there...5 or maybe 500 in our galaxy, I don't know.

I know that it is hard to get to the level of intelligent civilization, it is not hard for such civilizations to self destruct...and we are very very very far away from each other.



#20 sg6

sg6

    Fly Me to the Moon

  • *****
  • Posts: 5253
  • Joined: 14 Feb 2010
  • Loc: Norfolk, UK.

Posted 27 June 2019 - 12:55 PM

Seems a good chance that just about most suitable planets will have life. Life started on earth soon after we cooled down sufficently. So it would seem life can get going fairly rapidly, and by that easily easily also.

 

Stars like our sun (?), define.

Seem also that we can disregard the core, and the outer arms, insufficent metals in the outer arm.

So a G type star "similar" to our own may need to include suitably located with regards distance out from the center and in from the edge.

 

Then comes  "Life" ?

Single cell slime, plants only, big and toothy, intelligent and/or technological (< May include big and toothy I suppose)

 

One of the Drake ideas was that life developes intelligence. Well 3 geological periods of dinosaurs seems to disprove that.

 

Dolphins demonstrate intelligence but on a water world they will not develop steel or electronics.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics