B How hard is it to detect extinct comets?

[xpell]

TL;DR Summary

Since cometary nuclei have such a low albedo, are they very difficult to detect?

Hi! I have read that cometary nuclei have a very low albedo, even lower than coal or asphalt. Because of this, they absorb lots of light and heat rather than reflecting them. So I was wondering how hard is it to detect extinct comets. Could the solar system be full of dead nuclei buzzing around that we are just unable to "see" using current technology, or are they usually detected somehow?

Thank you in advance!

 

[davenn]

hi ya

Summary:: Since cometary nuclei have such a low albedo, are they very difficult to detect?

I have read that cometary nuclei have a very low albedo, even lower than coal or asphalt.

"I have read..." is not a good thing without context or links to where as we don't know what you
were reading, how reliable it was or if you may or may not have taken it out of context ( misunderstood).

Generally, comets are classified as dirty snowballs, and don't always have a completely solid nuclei.
Hence why I would like to know what you were reading.

So I was wondering how hard is it to detect extinct comets.

Have to say, I had never heard of "extinct" comets had to google that and after reading I get the idea.

Wiki has a reasonable article on such things
https://en.wikipedia.org/wiki/Extinct_comet

Their suggestion is that some 6% of near Earth asteroids are likely to be extinct comets.
And this sort of answers your question about their detection, it would be much the same as
any other asteroid with size and albedo being the main factors in their detection.Dave

 

[xpell]

Hi, Dave,

"I have read..." is not a good thing without context or links to where as we don't know what you
were reading, how reliable it was or if you may or may not have taken it out of context ( misunderstood).

Well, I have read it in many different places, including that Wikipedia article. Their average albedo seems to be around 0.05, which is really low...

Their suggestion is that some 6% of near Earth asteroids are likely to be extinct comets.
And this sort of answers your question about their detection, it would be much the same as
any other asteroid with size and albedo being the main factors in their detection.

...and that's why I was wondering if there's the possibility of lots of "non-near-Earth" objects orbiting the Sun which are no longer outgassing and are impossible to detect using currently available observation technology, or there are instruments or techniques to find them.

Another possible, closely related question would be: "Is it possible to detect a comet before it starts outgassing? How big / far away?"

 

[davenn]

Hi, Dave,
………………………...

Another possible, closely related question would be: "Is it possible to detect a comet before it starts outgassing? How big / far away?"

Would depend on size but as a generalisation most start outgassing between the orbits of Jupiter and Saturn.
There, of course, depending on the composition etc, will be variations