Astronomers find record-breaking haul of starless 'rogue' planets

Near the end of the report, "The researchers saw infrared energy emitted by 70 to 170 gas-giant rogue planets, they report in the new study, which was published online today (Dec. 22) in the journal Nature Astronomy. (Young rogues of this heft glow with the heat of their formation for the first few million years of their lives.) "

Most if not all seem to be within 420 light years from Earth. That is a bunch of rogue exoplanets floating around in space :) Doing follow up observations like direct imaged exoplanets, radial velocities, primary transits, etc. looks difficult. Bunches of potential free floating planets near the Sun will be challenging to explain their origin. Perhaps gas clouds that evolve into people are very rare :)
 
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Most if not all seem to be within 420 light years from Earth. That is a bunch of rogue exoplanets floating around in space :) Doing follow up observations like direct imaged exoplanets, radial velocities, primary transits, etc. looks difficult.
Yes, they radiate much less light than red dwarfs, which are also hard to see.

Bunches of potential free floating planets near the Sun will be challenging to explain their origin.
Perhaps, but I kinda doubt it. Most star systems have one or more companion stars. Their disks would have been more massive than most single star formations, I would guess. So, more larger planets would be likely. Migration is now highly favored for formation models, so to find many rogues out there would seem logical. There would be far more smaller rogue planets, I suspect, but these are even harder to see.

Perhaps gas clouds that evolve into people are very rare :)
We disagree on our gaseous nature. Do you not eat frijoles? ;)
 
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Perhaps in 3+GY when Andromeda and the Milky Way galaxies get friendly, our solar system may be torn apart and Earth flung into the "orphanage" for sunless planets. An event I'll gladly miss.
 
Perhaps in 3+GY when Andromeda and the Milky Way galaxies get friendly, our solar system may be torn apart and Earth flung into the "orphanage" for sunless planets. An event I'll gladly miss.
All that astronomy gear should be held until that day as prices will get high as more people see the great light show.

I wonder, however, what the odds are that our solar system would be significantly altered. Collisions are extremely rare, but close encounters seem likely. But how close does a star have to come? My guess far less than one light year for a solar mass star.

Over time, we've had many visitors wave hello. Here is one that came within the Oort Cloud only about 70k years ago... Scholz's star.
 
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After more reading on this intriguing report I pass along these observations.

Astronomers uncover largest group of rogue planets yet, https://phys.org/news/2021-12-eso-telescopes-uncover-largest-group.html

Reference paper, A rich population of free-floating planets in the Upper Scorpius young stellar association, https://www.nature.com/articles/s41550-021-01513-x, 22-Dec-2021.

My observation. From the abstract cited, "Therefore, ejections due to dynamical instabilities in giant exoplanet systems must be frequent within the first 10 Myr of a system’s life." My note. All these possible rogue planets reported are dated very young in the area near the Sun studied (relative to the age of the Sun, some 4.6 billion years old), perhaps 10 million years old or less. One possible formation mechanism identified is ejection from other planetary systems that formed (obviously very recently too relative to the solar system age). This seems to require much catastrophism and violence during protoplanetary disk evolution events postulated to explain the origin of planets. Another question, what is the MMSN protoplanetary disk mass and size needed for large scale, planetary ejections to create a population of rogue planets in the MW? Recent studies on interstellar objects (much smaller than rogue planets) said to pass through our solar system, were ejected from massive disks. Our Sun MMSN is only about 3,330 earth masses or so in many models. My note, from the phys.org report, "We did not know how many to expect and are excited to have found so many,". This indicates that a specific origin model using gas clouds and protoplanetary disks, did not predict how many rogue planets could be found, so the exact formation of rogue planets is not certain, like heliocentric solar system astronomy. Example, measurements for the solar parallax based upon Mercury and Venus transits, used to define the distance between Earth and the Sun or observations of the phases of Venus. My note. The phys.org report states, The study suggests there could be many more rogue planets that have not been discovered. "There could be several billions of these free-floating giant planets roaming freely in the Milky Way without a host star," Bouy explains." My note. This suggest that billions of rogue planets may exist, free floating in the MW. Do observations like this impose constraints on the postulated evolutionary events in the solar, protoplanetary disk that Earth is said to evolve from? Example, what constrained our Earth from evolving, *naturally* into a wandering, rogue Earth in the MW?
 
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This suggest that billions of rogue planets may exist, free floating in the MW.
Yes, but that is a SWAG at this point. The total no. of planets in the galaxy could be close to one trillion, also a SWAG, so one billion would be only 0.1% that are rogue.

Do observations like this impose constraints on the postulated evolutionary events in the solar, protoplanetary disk that Earth is said to evolve from?
I don't think so, especially not as far as constraints. It may, however, better explain a massive planet in the far Kuiper Belt (Planet 9), if such a thing exists.

It's likely that the multiple star systems, during the early dynamic period -- sometimes described using a pin ball machine analogy -- provided the ejection forces to send a mass that of a planet to go sailing out of the system.

Example, what constrained our Earth from evolving, *naturally* into a wandering, rogue Earth in the MW?
It takes more than one massive object to combine with another in order to send a third, large object sailing. Although Jupiter and the Sun might greatly effect the Earth's history, the odds are small, IMO, that Jupiter would have migrated in far enough to do so.
 
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Helio, your post #7 does not answer *what constrained our Earth...*. You said, "It takes more than one massive object to combine with another in order to send a third, large object sailing. Although Jupiter and the Sun might greatly effect the Earth's history, the odds are small, IMO, that Jupiter would have migrated in far enough to do so."

You are ignoring all the hot jupiters documented, sub-neptunes, super-earths documented, all moving around their parent stars inside of where Mercury is today in our solar system. Such planetary evolution like this in our solar system, we may not be here today :) There are no constraints offered using the MMSN protoplanetary disk when many other exoplanet systems suggest an Earth size body would face serious problems forming and being habitable today around our Sun based upon exoplanet observations. Apparently time, chance, random collisions, and various postulated initial disk sizes and masses that accreted at different rates and likely different ejections, allowed Earth to evolve into the habitable planet we live on today. Even something like Theia hitting the proto-earth, wrong configurations here destroy the proto-earth, thus no Earth today.
 

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