Speaking of a moon- could part of this planet's calculated mass be a moon?

Space/Science » in reply to re: Did some digging. maybe this will help. Thanks, REB.

Speaking of a moon- could part of this planet's calculated mass be a moon?

REB — 4/26/2007 2:34:40 PM (archived)

For example, could the planet have a mass of 3 Earth's and a moon with a mass of one Earth? But we are seeing it as one world with a mass of 4 Earths?

That could be an Earth size moon?

As for being tidal locked or not. One thing I have learned from studying our Solar System, things donâ€™t always conform to our predictions and conceptions. Jupiterâ€™s moons were all supposed to be cold, dead, crater, uninteresting moons. The relation of water on Mars has changed numerous times. Venus was not supposed to be so hot. And Triton and Enceladus geologically active- oh please, they are far to small in mass.

So with Red Dwarf stars and their planets. Some will probably be tidally locked, but I bet not all. There will be factors we donâ€™t see right now that have them rotating. Massive impactors, large moons, or who knows what else. True, physical laws are the same across our universe, but we just donâ€™t know all the factors that come into play.

Each system will have its own behavior based on certain conditions there.

The whole thread (70 posts)

Earth-like planet, with water, around red dwarf Gliese 581? - REB - 4/24/2007 7:31:46 PM
- Are we *sure* it'd have volatiles? - dtb - 4/26/2007 1:13:42 PM
  - No such thing as sure - nick hoffman - 4/26/2007 11:37:36 PM
- It's actually has a diameter 50% larger than our world. - Jacob Samorodin - 4/25/2007 11:16:43 PM
  - re: Would the absense of a magnetic field be as catastrophic to the atmosphere of a red-dwarf planetary system? - The Artist formerly known as Scott Evil - 4/26/2007 3:15:47 AM
    - Solar wind - nick hoffman - 4/26/2007 9:53:47 AM
      - re: Solar wind - Joe P. - 4/26/2007 4:49:47 PM
        
        "day" and "year" - nick hoffman - 4/26/2007 11:47:47 PM
      - very interesting... Now we need a imaging telescope that can tell us more! - The Artist formerly known as Scott Evil - 4/26/2007 1:40:37 PM
- re: The discoverer - Raoul - 4/25/2007 6:24:36 AM
- Two interesting facts... - TB - 4/25/2007 6:12:00 AM
- Couple of questions: - TB - 4/25/2007 5:46:25 AM
  - re: Couple of questions: - REB - 4/25/2007 1:37:28 PM
    - Splitting Hairs - 3 days per 2 years - M.A.E. - 4/25/2007 9:06:37 PM
      - Who needs an atmosphere? - nick hoffman - 4/25/2007 11:10:46 PM
        
        Good point but - M.A.E. - 4/26/2007 2:31:25 AM
        
        re: Good point but - Excellent points by both of you (MAE & Nick). - Marcia - 4/26/2007 8:44:42 PM
    - re: Couple of questions: - Raoul - 4/25/2007 2:15:50 PM
      - Did some digging. maybe this will help. - REB - 4/25/2007 2:30:44 PM
        
        re: Did some digging. maybe this will help. Thanks, REB. - Marcia - 4/26/2007 2:03:16 PM
        
        Speaking of a moon- could part of this planet's calculated mass be a moon? - REB - 4/26/2007 2:34:40 PM
        
        Not 4 Earth masses- 5 Earth masses. - REB - 4/26/2007 2:57:26 PM
        
        I would love to see a true binary-planet... Where two relatively equal planets are sharing the same center of gravity. - The Artist formerly known as Scott Evil - 4/26/2007 4:25:03 PM
        
        I wonder what it would have been like to have Venus as our moon. - REB - 4/26/2007 9:57:49 PM
        
        Very Good point! - The Artist formerly known as Scott Evil - 4/26/2007 2:50:57 PM
        
        Good detective work. You were correct! - ER - 4/25/2007 3:13:11 PM
      - re: Couple of questions: - REB - 4/25/2007 2:22:58 PM
  - re: Couple of questions: - ER - 4/25/2007 11:19:37 AM
    - re: The flares could themselves result in "seasons" on such a planet. - The Artist formerly known as Scott Evil - 4/25/2007 2:44:07 PM
      - Interesting... - nick hoffman - 4/25/2007 11:07:18 PM
        
        I've always thought of seasonality as being critical to drive evolution. - The Artist formerly known as Scott Evil - 4/26/2007 3:26:56 AM
        
        re: I've always thought of seasonality as being critical to drive evolution. - Joe P. - 4/26/2007 4:55:37 PM
        
        Interesting idea, I've started a new thread on it, I hope you don't mind. (n/t) - ER - 4/26/2007 2:36:15 PM
        
        Not at all. - The Artist formerly known as Scott Evil - 4/26/2007 2:53:31 PM
        
        Well Evolution Requires Either Genetic Drift Or Selective Pressure - M.A.E. - 4/26/2007 2:07:13 PM
        
        Getting wiped out can be good for evolution. - The Artist formerly known as Scott Evil - 4/26/2007 4:40:25 PM
      - Donâ€™t Red Dwarfs flair when they are young and calm down as they get older? - REB - 4/25/2007 2:48:57 PM
        
        Flares last minutes, maybe an hour or so (n/t) - phil - 4/25/2007 2:52:33 PM
        
        I mean a Red Dwarfâ€™s Flare frequency goes decreases as the star ages. - REB - 4/25/2007 2:55:23 PM
        
        rI'm specificly referring to red dwarf flare times (n/t) - phil - 4/25/2007 2:59:20 PM
  - Found a few answers - TB - 4/25/2007 6:13:19 AM
    - Also, what about moons, double planets - Sawyer - 4/25/2007 1:10:56 PM
      - Massive solar tides - ER - 4/25/2007 1:37:21 PM
        
        Tides - phil - 4/25/2007 2:58:39 PM
        
        Not sure about that... - TB - 4/25/2007 2:34:07 PM
        
        I think it would depend on the specific make-up of the planet and it's atmosphere (if any) - The Artist formerly known as Scott Evil - 4/25/2007 2:46:52 PM
        
        You're right about the tides, senior moment on my part. - ER - 4/25/2007 2:44:57 PM
        
        Don't be too hard on yourself - TB - 4/25/2007 4:25:37 PM
        
        re: You're right about the tides, senior moment on my part. - REB - 4/25/2007 2:57:21 PM
        
        re: Massive solar tides - REB - 4/25/2007 1:51:15 PM
        
        re: Massive solar tides - ER - 4/25/2007 3:09:29 PM
        
        Mercury - nick hoffman - 4/25/2007 10:50:38 PM
- Well, that's not fair... - TB - 4/25/2007 5:44:30 AM
- Data on this Star (from 2nd Gleise Catalog) - ER - 4/25/2007 12:03:02 AM
- Wow! - Peter Bruener - 4/24/2007 9:28:05 PM
  - re: Wow! - Raoul - 4/24/2007 9:41:52 PM
  - I got the size wrong. This planet is 50% larger than the Earth. - REB - 4/24/2007 9:38:30 PM
    - 2.2Gs at 5 Earth masses and 1.5 Earth radii - phil - 4/24/2007 9:50:09 PM
      - Thanks Phil - Peter Bruener - 4/25/2007 5:03:02 AM
        
        AP says 1.6G; I don't get it (n/t) - phil - 4/25/2007 4:01:24 PM
        
        Either way it would be a great place to train athletes (n/t) - FrankC - 4/26/2007 9:43:21 PM
        
        That seems high. Jupiter is something like 2.3-2.4 with over 300 times the mass of Earth. (n/t) - REB - 4/25/2007 4:17:52 PM
        
        Huge Difference In Density - M.A.E. - 4/25/2007 9:27:29 PM
        
        How do they know the radius? - ER - 4/25/2007 10:30:48 PM
        
        They Don't - M.A.E. - 4/26/2007 2:17:47 AM
        
        Radius - depends on density which depends on compositionj which depends on.... - n - 4/25/2007 11:24:02 PM
        
        A relevant paper online... - Adam - 4/27/2007 2:04:02 PM
        
        re: That seems high. Jupiter is something like 2.3-2.4 with over 300 times the mass of Earth. - ER - 4/25/2007 4:59:18 PM
- re: ESO discovery ! - Raoul - 4/24/2007 8:50:06 PM
  - D'oh! 50% larger than the Earth, not smaller. - REB - 4/24/2007 8:57:43 PM

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