A super-Earth beyond Mars would have made Earth nearly uninhabitable

The video in this article is interesting. It shows small rocky planets sublimating from dust at a particular radius in the protoplanetary disk and migrating inward toward the star, making room for another planet to form at the original radius and then also move inward. The concept is that the process makes smaller rocky planets from a less dense disk and larger rocky planets from more dense disk.

Which gets me to thinking about the difference between that and the development of the giant gas ball planets farther out.

In our solar system, there is an asteroid belt between the 2 classes of planets. I am wondering if that is not actually a demarcation of the transition in the formation processes between the 2 types of planets. I doubt we could detect an asteroid belt around even the closest star to us, with current technology. So, I am wondering how common some sort of asteroid belt really is.

The video also shows part of a graphic depicting the relative sizes of planets in the systems we have found (for the planets in them that we have been able to detect, so far). That part of the graphic displayed in the video does not show any mix of small and large planets at all, not even one like our own solar system, with small rocky inner planets surrounded by larger gas giants.

So, I am wondering if we are even detecting all of what is our there around each star.

And, I am wondering why a rocky "super earth" would for outside a batch of smaller rocky planets, anyway. As the dust disk is depleted, I would expect smaller planets, not larger ones.

And, if the largest gas giant forms outside of the zone where rocky planets tend to form, then that might well disrupt the development of a rocky planet near its orbit, just like the simulations suggest a large planet in the location of our asteroid belt would disrupt the inner planets.

Questions:
1. Does anybody know where I can find the full graphic for exoplanet sizes in each star system?
2. What is the total mass of the asteroids in our system? How many "Earths" would that make?

Answer for Q2: "The total mass of the asteroid belt is estimated to be 2.39×1021 kg, which is just 3% of the mass of the Moon." from https://en.wikipedia.org/wiki/Asteroid

So, it seems that the rocky planet material in the inner disk was scant at that radius. Was that because it was accumulated into Jupiter? Do we know how much rocky material lies in the center of Jupiter?
 
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Nov 26, 2024
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Has anyone ever simulated our solar system *without* the presence of Mars?
What effect would that have on Earth's climate, make it milder to the point that life does not evolve?
 
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The giants are formed past the Frost Line, where gas density is much higher in ice form, as I understand it. The protonsun was about 25% cooler, so the frost line was not as far out.

But migration seems to be likely in all systems. Gas and dust are held out by stellar radiation and winds, so they revolve slower. But as they form into planetismals, these pressures aren’t so effective, thus inward migration occurs.

Even the more distant giants can migrate very close to their host (e.g. Hot Jupiters).

IIRC, Nice (France) has a Monte Carlo model that models our solar system fairly well, except for Pluto. Serious migrations took place, according to the model. Jupiter migrated inward until resonant with Saturn, when they both moved outward, I think.
 
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Thanks Helio,

What I would be interested in seeing is any system with a gas giant in a closer orbit than some rocky planet the size of Earth or Mars. Do you have a way to scan the table for parameters like that (e.g.,, is it in Xcell)?
 
Here is a quick table showing M-class systems. The Solar Equivalent distance is calculated.

The bright green highlight are the exos that are the largest in a multisystem and are also closest to the star.

Note that many radii are similar, so the error bars could change the results somewhat. I also estimated the radii given a known distance that could be used to get an approximate density. So if mass is stated, then these radii are estimated.





 
Thanks for the table, Helio.

I am only seeing one entry with a radius that looks like a "Jupiter" - AU Mic c at 30. 61 earth radius. And that seems to be outside of the other rather large planet at 4.69 Earth "radius" (diameter ?). Is that inner planet a large rocky super-earth?

I thought we had more "hot Jupiters" on our exoplanet list. But I am not seeing them here.

The green highlighted entries all look like various sized rocky (?) planets with other similar sized rocky neighbors. Not really different than mars being outside Earth, and Venus from a formation consideration.

I guess we really are not detecting enough planets to draw any firm conclusions. If we can find a "hot Jupiter", can we also expect to detect a much smaller rocky planet in a wider orbit? Or, does the mass of the large inner planet make it hard to see small wobbles in the star's position. I guess we should still be able to see transits of smaller planets.
 
I had limited time so I took some short cuts for now. The M class likely has smaller planets, I think. The K, F, and G-class have many more exos. Also, I think I limited the sizes a bit.

Have a nice Thanksgiving. I’ll have more time in a few days for a bigger gulp.
 
Helio, to save you some work, I am not trying to focus on the relative sizes of the rocky planets as a function of distance from their star. What I am looking for is the relationship of the rocky planets to the gas giants around the same star. So, I would mainly be interested in where we have found gas giants, and where any rocky planets more the size of Earth and Venus are found in the same systems.

I am sort of seeing a pattern in our own solar system that has small rocky planets nearest the Sun, with thin atmospheres, then gas giants farther out with maybe small rock cores but extremely dense and thick atmospheres, the ice minor planets outside those, with thin atmospheres, mainly because the gases have solidified onto their surfaces.

I am wondering if other planetary systems follow a similar pattern, or if we see a lot of divergences from that pattern.

Thanks for your efforts so far, and have a safe and happy Thanksgiving. No need to hurry your response.
 
Sounds interesting.

To determine if an exo is “rocky” we can set an orbital range. Using solar equivalent distances, perhaps 0.1 to 3 AU (~ Frost line)? I’ll likely use an exo size < 2.5 Earth radius for these. [ Frost line during the protoplanet period was ~ 2.7 AU, apparently, possibly less.]

For some reason, exoplanet.eu includes massive bodies including brown dwarfs. But I’ll not set any limit for the first run.

I’ll list all systems that have both the giants — Re > 9 (Saturn), unless you have another minimum — and one or more rocky planets.
 
Helio, to save you some work, I am not trying to focus on the relative sizes of the rocky planets as a function of distance from their star. What I am looking for is the relationship of the rocky planets to the gas giants around the same star. So, I would mainly be interested in where we have found gas giants, and where any rocky planets more the size of Earth and Venus are found in the same systems.

I am sort of seeing a pattern in our own solar system that has small rocky planets nearest the Sun, with thin atmospheres, then gas giants farther out with maybe small rock cores but extremely dense and thick atmospheres, the ice minor planets outside those, with thin atmospheres, mainly because the gases have solidified onto their surfaces.

I am wondering if other planetary systems follow a similar pattern, or if we see a lot of divergences from that pattern.

Thanks for your efforts so far, and have a safe and happy Thanksgiving. No need to hurry your response.
I've come up with something in my limited kit of magical programing tricks, but I thought the Exoplanet Stats might be the better place for it...here.
 
Interesting to see computer simulations showing how Earth evolved in a spinning disc without being destroyed :) There are now 7360 confirmed exoplanets at this site, https://exoplanet.eu/home/

Just looking at exoplanets in the range from 0 to 3 au from their parent stars, simple descriptive stats shows how different we really are here in our solar system.

4343 are found 3 au or closer, average host star mass is 0.93, average exoplanet mass is 5.21 Jupiter mass, much more than we have from Mercury to asteroid belt at 3 au here. The largest exoplanet is 70 Jupiter masses.
 
Rod,

If seems you’re very right in seeing the solar system as more unique. Look at the list as linked to in post 14.

The solar system would be a 22277…. ignoring Mercury. I see almost none that have inner small planets followed by massive larger ones.

The sample size is, admittedly, smaller than I would like to see in order draw any conclusions, but the trend favors our uniqueness. The fact that there are no models, apparently, of our solar system where a more serene disk-to-planet formation process could’ve taken place helps explain our uniqueness. The best model, IIRC, has Jupiter migrating and creating havoc, but was pulled back by Saturn once in resonance.

iPhone
 
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We are so unique in the Milky Way that there are probably only hundreds of thousands to some few millions of solar systems with Earth-like to near Earth-like planets orbiting in the right zones.

But thanks to our own visions of in-space customized colonization and settlement I have to wonder how many possible billions of star systems -- out of hundreds of billions and more -- might already be partially occupied by life due to advanced life gone [far-flung-frontier-colonizing] mode in hordes of colony 'Space Arks' from their originating homeland systems.
 
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earth-like exoplanets is an interesting concept IMO :)

https://exoplanet.eu/home/, this site reports 329 with radii 1.1 or less earth size. The mean au is 0.06 au from host star, min is 0.0034 au and max 1.137 au. Mean or average mass is 15.75 earth masses. TRAPPIST-1 system is in the query too.

https://exoplanetarchive.ipac.caltech.edu/index.html, this site reports 286 with radii 1.1 or less earth size. The mean or average mass is 8.93 earth masses. TRAPPIST-1 system is in the query too.
 

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