'Megacomet' Bernardinelli-Berstein is largest ever seen, Hubble telescope confirms

[Admin]

A gigantic comet is actually the largest ever seen, new observations by the Hubble Space Telescope confirm.

'Megacomet' Bernardinelli-Berstein is largest ever seen, Hubble telescope confirms : Read more

 

[rod]

I note this about the period of the comet, "This comet, being so far from Earth and originating in the farthest-flung reaches of our solar system, is thought to travel on a 3-million-year-long elliptical orbit around the sun. Scientists think that it might travel about half a light-year away from the sun in the farthest parts of its orbit."

It gives the impression the comet observation, fits nicely with the 4.5 billion years old solar system model. If I asked, how many perihelion passages of this comet is factually observed, consider it takes 3 million years to complete one orbit, what is the answer?

So does the comet observation fit the theory of 4.5 billion years old solar system or is the comet observation fitted into the theory of 4.5 billion years old solar system?

 

[billslugg]

The 3,000,000 year orbit estimate is based on the speed at perihelion and the distance at perihelion. The age of the solar system has nothing to do with it.

 

[rod]

The 3,000,000 year orbit estimate is based on the speed at perihelion and the distance at perihelion. The age of the solar system has nothing to do with it.

Unfortunately, how the comet is reported does have everything to do with the age of the solar system. Here is an example.

4 billion-year-old relic from early solar system heading our way (phys.org)

"Comets, among the oldest objects in the solar system, are icy bodies that were unceremoniously tossed out of the solar system in a gravitational pinball game among the massive outer planets, said David The comet is now less than 2 billion miles from the sun and in a few million years will loop back to its nesting ground in the Oort cloud, Jewitt said."

 

[billslugg]

Here is the only mention of the possible age of the comet. It is a statement without any backup data, source or logic. They are simply making the assumption the comet has been around billions of years. There is no way to tell how long it has been around by looking at it. The only thing we can surmise is its orbital period. It could be on its 1500th trip in to the Sun or its first. It has probably been around since the beginning but that's just my guess. So the answer to your original question is "they fit the comet to the age of the solar system".

"The Oort cloud's comets were tossed out of the solar system billions of years ago by the gravitation of the massive outer planets, according to Jewitt. "

 

[rod]

Here is the only mention of the possible age of the comet. It is a statement without any backup data, source or logic. They are simply making the assumption the comet has been around billions of years. There is no way to tell how long it has been around by looking at it. The only thing we can surmise is its orbital period. It could be on its 1500th trip in to the Sun or its first. It has probably been around since the beginning but that's just my guess. So the answer to your original question is "they fit the comet to the age of the solar system".

"The Oort cloud's comets were tossed out of the solar system billions of years ago by the gravitation of the massive outer planets, according to Jewitt. "

You are on the right track here, unfortunately, the problem is in the published paper too.

Hubble Space Telescope Detection of the Nucleus of Comet C/2014 UN271 (Bernardinelli–Bernstein) - IOPscience

"1. Introduction Long-period comets are considered to be compositionally some of the most pristine leftovers from the early solar system. For most of their lifetime, they have been stored in the low-temperature environment of the Oort cloud, at the edge of the solar system (Oort 1950). Recent years witnessed identifications of several long-period comets active at ultralarge heliocentric distances (rH ≳ 20 au), implying that the long-period comets may be more thermally processed than previously thought (Jewitt et al. 2017, 2021; Meech et al. 2017; Hui et al. 2018, 2019; Bernardinelli et al. 2021). Unlike most comets that are only active within the orbit of Jupiter (rH ≲ 5 au), driven by sublimation of water ice (e.g., Whipple 1950), the cause of activity in distant comets remains unclear..."

As you stated very clearly, *So the answer to your original question is "they fit the comet to the age of the solar system".*

Reporting like this gives the impression that the radiometric age of meteorites used to establish the age of the solar system, determined by Clair Patterson in mid-50s to be some 4.56 billion years old, is a non-falsifiable age for the solar system, my opinion. There are many objects documented today in the solar system that show much younger ages like the lifetime of comets in the solar system. Young ages reported for different objects in the solar system (even short lived asteroids) are simply fitted into the accepted age model.

 

[sam85geo]

An informative discussion, thanks. I'm really interested in what that mega comet will look like in the sky as it ostensibly whizzes by far away from Earth and are there more "Mega Comets" lurking "out there"? IMO. We really need to do more preparations for a possible "Oh! Crap" realization.

 

[billslugg]

It is perfectly reasonable to assume the comet is a pristine example from the beginning of the Solar System. Assumptions are OK if you have no other choice and if you call them out. That is why they say "considered to be" and not "proven to be".

There are plenty of objects younger than 3.56B years. Lots of reprocessing has gone on.

 

[rod]

It is perfectly reasonable to assume the comet is a pristine example from the beginning of the Solar System. Assumptions are OK if you have no other choice and if you call them out. That is why they say "considered to be" and not "proven to be".

There are plenty of objects younger than 3.56B years. Lots of reprocessing has gone on.

This now becomes a good example of post #6 comments. *It is perfectly reasonable to assume the comet is a pristine example from the beginning of the Solar System.*

My observation. None of the comet observations define when the beginning took place.

*Lots of reprocessing has gone on.*

My observation. This cannot be proven, it is a methodology to reconcile conflicting younger age measurements found in the solar system with the meteorite age model keeping it non-falsifiable.

 

[billslugg]

Yes, none of the comet observations define when the beginning took place. We can't tell how old a comet is by looking at it. We just assume it has been here all the time.

Of course reprocessing has gone on. Just look at any volcano on Earth. Look at craters on the Moon.

Younger meteorites do not constrain the age of the Solar System to a more recent time. Older meteorites do place constraints on how old it must be. This if you assume the older ones are not interstellar. They could be, but the chances are against it.

 

[rod]

Yes, none of the comet observations define when the beginning took place. We can't tell how old a comet is by looking at it. We just assume it has been here all the time.

Of course reprocessing has gone on. Just look at any volcano on Earth. Look at craters on the Moon.

Younger meteorites do not constrain the age of the Solar System to a more recent time. Older meteorites do place constraints on how old it must be. This if you assume the older ones are not interstellar. They could be, but the chances are against it.

*We just assume it has been here all the time.*

This is the problem I identified in post #6 comments. My opinion, I doubt Tycho Brahe debating the geocentric solar system model vs. the heliocentric solar system model would accept thinking like this in science (an example is the problem of showing stellar parallax observations that can support the heliocentric solar system or failing to see the phases of Venus). Same for Galileo, Kepler, and Newton. I could assume this for the age of Saturn's ring system too. The Moon and bombardment is a difficult subject. There are no telescope observations showing when all the craters formed or how far away the Moon was from Earth, when the craters formed. This introduces another line of assumptions.

 

[billslugg]

We accept assumptions when we have no other choice. As long as we call them out there is nothing wrong with it.