Ultradense asteroids hint at elements alien to us here on Earth!

[Leo S]

I found this quite interesting. Are ultradense asteroids made of elements not seen on Earth?

I'm also puzzled, why, if these things really exist, we don't find them as meteorites here on Earth, or detect their signature via spectroscopy, as we would with other elements.

I guess the last part is answered by:

Quote

composed of unknown types of ‘ultradense’ matter that cannot be studied by conventional physics.

 

[Gfamily]

As far as I can tell, there is no good knowledge of the mass of the asteroid.

The best estimate comes from a mathematical model of the solar system that interprets ephemeris data to determine how interactions between Asteroids allow calculations of masses

The asteroid itself is included in the paper for the 2010 version of the model (though that itself notes that the mass is 'unrealistic'). Later iterations of the paper do not include the asteroid in their tabulations.

Using a clearly unreasonable value for the mass as a basis for hypothesising the existence of ultradense matter (almost 4x the density of the most dense element) is umm, a stretch!

A paper containing the density calculation https://arxiv.org/pdf/1203.4336.pdf

Another paper giving the tabulated mass (not included in later versions)

https://arxiv.org/pdf/1011.4419.pdf

Edited October 22, 2023 by Gfamily
Update details of what's in the papers

[Leo S]

Thanks for the reply. That would certainly make more sense.

The papers you cite are quite old however, so I'm not entirely sure that current density estimates are quite so bad given that there has been a big focus on asteroids (due to the impact risk) over the last 10+ years, including multiple sample return missions from asteroids (most recently the sample return from Bennu), which must have given opportunities to calibrate I would have thought.

Either way it'll be interesting to see how (or if) this story plays out.

Edited October 22, 2023 by Leo S

[Gfamily]

The issue as I see it, is that measuring density of individual asteroids is more than a bit tricky. It essentially comes down to measuring the perturbation of the asteroid as it is approached by other asteroids or planets (assuming you know the mass of the other).  

There are some asteroids for which we do have reliable masses, which are generally consistent - S type asteroids having lower density than M type asteroids. Of course, those to which we have sent missions have very precise masses - and Dawn visited both Ceres and Vesta (S type and M type respectively). 

On the basis that we have meteor remains that have densities that correspond to those of well established asteroids, we don't have a problem with most of them.

Nothing so far suggests that there is anything to support the idea of 'elements unknown to science' being part of asteroid 33 Polyhymnia.

[DaveS]

As expected Jordan goes off the deep end...

For myself I think this whole hoo-ha is down to accumulated measurement errors.

 

[Leo S]

On 22/10/2023 at 21:19, Gfamily said:

The issue as I see it, is that measuring density of individual asteroids is more than a bit tricky. It essentially comes down to measuring the perturbation of the asteroid as it is approached by other asteroids or planets (assuming you know the mass of the other).  

There are some asteroids for which we do have reliable masses, which are generally consistent - S type asteroids having lower density than M type asteroids. Of course, those to which we have sent missions have very precise masses - and Dawn visited both Ceres and Vesta (S type and M type respectively). 

On the basis that we have meteor remains that have densities that correspond to those of well established asteroids, we don't have a problem with most of them.

Nothing so far suggests that there is anything to support the idea of 'elements unknown to science' being part of asteroid 33 Polyhymnia.

Thanks again for your thoughts. You are obviously more familiar with the subject than I.

I can certainly appreciate how an error in the estimated density might be misleading, and as you say there is no need to invoke theoretical ultradense elements to explain away a likely error in the estimate.

If it really was the case, then we would have detected them (in meteorites or meteor spectra), which is what puzzled me to begin with, and why I remain skeptical of the claims, although I try to keep an open mind!