Earth-like planets may be more common than you think

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Anaxagoras
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Earth-like planets may be more common than you think

Post by Anaxagoras » Mon Aug 19, 2019 11:18 pm

How many Earth-like planets are around sun-like stars?

For purposes of this study, the planets they are including in this category are as follows:
Based on their simulations, the researchers estimate that planets very close to Earth in size, from three-quarters to one-and-a-half times the size of earth, with orbital periods ranging from 237 to 500 days, occur around approximately one in four stars. Importantly, their model quantifies the uncertainty in that estimate. They recommend that future planet-finding missions plan for a true rate that ranges from as low about one planet for every 33 stars to as high as nearly one planet for every two stars.
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Abdul Alhazred
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Re: Earth-like planets may be more common than you think

Post by Abdul Alhazred » Mon Aug 19, 2019 11:31 pm

So that "earth like" may be a valid term of art for astronomers, but gee whiz what the science journalists will make of it.
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Re: Earth-like planets may be more common than you think

Post by Anaxagoras » Mon Aug 19, 2019 11:43 pm

Right. Obviously, not all planets in that category would be hospitable to life. Some will probably be like Venus, and others like Mars. Probably fewer earths than marses or venuses.

But it is one number in the Drake equation.
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Re: Earth-like planets may be more common than you think

Post by Anaxagoras » Mon Aug 19, 2019 11:52 pm

Out of curiosity I looked up the orbital periods of Mars and Venus. Venus is 225, so just under the lower limit, while Mars is 687, above the upper limit. I think Mars is also too small to fall into the category. Still, planets in the category might be closer to Venus or to Mars than to Earth if they lack a magnetic field.
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Re: Earth-like planets may be more common than you think

Post by Abdul Alhazred » Tue Aug 20, 2019 12:48 am

Anaxagoras wrote:
Mon Aug 19, 2019 11:43 pm
But it is one number in the Drake equation.
A sort of progress I suppose.

One input to the Drake Equation is almost no longer an ass pull.
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Re: Earth-like planets may be more common than you think

Post by Rob Lister » Tue Aug 20, 2019 2:36 pm

Anaxagoras wrote:
Mon Aug 19, 2019 11:52 pm
Out of curiosity I looked up the orbital periods of Mars and Venus. Venus is 225, so just under the lower limit, while Mars is 687, above the upper limit. I think Mars is also too small to fall into the category. Still, planets in the category might be closer to Venus or to Mars than to Earth if they lack a magnetic field.
I don't want to second guess an article I haven't read because I'm too lazy, but isn't the size and type of star is part of that formula.

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Re: Earth-like planets may be more common than you think

Post by Anaxagoras » Tue Aug 20, 2019 10:22 pm

Rob Lister wrote:
Tue Aug 20, 2019 2:36 pm
I don't want to second guess an article I haven't read because I'm too lazy, but isn't the size and type of star is part of that formula.

Yes, I think that stars that are either too big or too small are not considered "sun-like".

ETA: Specifically, they only considered FGK stars. The Sun is a G type, F is one size larger and K is one size smaller.

https://iopscience.iop.org/article/10.3 ... 881/ab31ab
http://astro.vaporia.com/start/fgkstar.html
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Re: Earth-like planets may be more common than you think

Post by Witness » Wed Aug 21, 2019 1:46 am

The Universe wrote:A glut of Earth-like planets, with Earth-like inhabitants? Oh gOD, no! :x

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Re: Earth-like planets may be more common than you think

Post by Abdul Alhazred » Wed Aug 21, 2019 1:55 am

It'll be like that Pluto bullshit.

They'll change the proportion of earth-like planets up or down by adjusting the definition. :evil:
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