First interstellar comet in our solar system?

[Obi]

As you can see (starting here) it could very well be that the comet cluster (or parts of it) have already entered the solar system a while ago (around the year 2000) and have left their first imprints in the system (including earthh, itself). In fact, I think the cluster has already been detected throughout the solar system but just not officially recognized or called as such. I think it is likely that the whole solar system is already experiencing the effects of the first waves of the cluster, including earth.

Yeah, I agree. It could very well be that this comet is in fact part of the cluster.

 

[The Mechanic]

Some good papers about Oumuamua published last week:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JE006706

Plain Language Summary​

1I/‘Oumuamua is very strange and it is hard to explain where it came from. We looked at several different ices and the push they would give ‘Oumuamua as they evaporated. We found that the best ice is nitrogen (N2), which would explain many of the things we know about it. ‘Oumuamua was small, about half as long as a city block and only as thick as a three story building, but it was very shiny. The shininess is about the same as the surfaces of Pluto and Triton, which are also covered in nitrogen ice. We suggest ‘Oumuamua was probably thrown out of a young star system about half a billion years ago. Bodies like ‘Oumuamua may allow us to see what the surfaces of a so far unknown type of exoplanet, “exo‐Plutos”, are made of. In a following paper (Desch & Jackson, 2021) we show that orbital instabilities in which giant planets move around, as happened in our own outer solar system 4 billion years ago, could make and throw out large numbers of small pieces of nitrogen ice like ‘Oumuamua. ‘Oumuamua may be the first piece of an exoplanet brought to us.

and https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JE006807

Plain Language Summary​

Our Kuiper belt originally had much more mass than today, but an instability caused by Neptune’s migration disrupted their orbits, ejecting most of this material from the Solar System, and simultaneously causing numerous collisions among these bodies. There were thousands of bodies like Pluto, with N2 ice (like the gas in Earth’s atmosphere, but frozen) on their surfaces, and this instability would have generated trillions of N2 ice fragments. A similar fragment, generated in another solar system, after travelling for about a half billion years through interstellar space, would match the size, shape, brightness, and dynamics of the interstellar object 1I/‘Oumuamua. The odds of detecting such an object, as well as more comet‐like objects like the interstellar object 2I/Borisov, are consistent with the numbers of such objects we expect in interstellar space if most stellar systems ejected comets and N2 ice fragments with the same efficiency our solar system did. This implies other stellar systems also had Kuiper belts and similar instabilities. There are hints that some N2 ice fragments may have survived in the Oort cloud of comets in our Solar System. ‘Oumuamua may be the first sample of an exoplanet born around another star, brought to Earth.

The first paper goes a bit into why the nitrogen ice led to the 'pancake' shape basically by rounding the sun and losing a lot of mass. Though a lot of it is a bit beyond me

A picture from the second paper is attached to this message. It shows what is the theorized journey of it. And it entered the solar system in 1995 already!

Also, a video explanation of those papers from a nice person on youtube starts here:

In the video thumbnail is pretty much the shape and color it is theorized this body has. A bit like the surface of Pluto, nitrogen and tholins, but just 50m across. Pretty cool if you ask me!