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Interstellar (not the movie) #fireball

Ken Jamrogowicz
 

Denis Vida
 

I was actually meaning to write something about this today, as I noticed this event reared its head again. It's interesting to read it from Amir's perspective.
The story behind it is long, but I'll try to summarize the key points.

Recording an interstellar meteor has been somewhat of a holy grail for meteor scientists. It would mean that we have direct evidence that other Solar Systems work the same as ours, and we would be able to use its direction to figure out something about our neighboring planetary systems. After 'Oumuamua was discovered, it raised more questions than answers (it had a very unusual shape and showed no activity). Borisov was actually a comet (as expected), but it was humongous (we expected something smaller).

If you look into any meteor orbit database, you will find a plethora of "interstellar" meteors. The problem is that if you look into any of them closely and really try to robustly determine if they really are interstellar, you will soon run into problems (there are plenty of papers on the topic). The problem is that meteor velocity is very hard to measure, and in certain configurations even a tiny error in velocity can mean a huge difference in the final orbit. And guess what, all "interstellar" meteors we have seen so far are right on that border and can go either way. The old adage (that Amir mentions) is that "extraordinary claims require extraordinary evidence", which we simply don't have.

The CNEOS website (https://cneos.jpl.nasa.gov/fireballs/) lists bright fireballs that top secret US government sensors (spy satellites) observe from orbit. The utility of the website is simple - if there's a huge explosion in the atmosphere, they want the general public to know that it was not a nuclear weapon but a fireball. The final data product is public, they publish the time of the event, nominal velocity, radiant direction, and the total energy of the event (conveniently given in kilotons of TNT equivalent). The whole meteor and asteroid community monitors this website and we have learned over the years not to trust it. There are typos, some radiants can be off by as much as 40 degrees (!), and the velocities can also be quite off. We know this because we compared the measurements to high-accuracy ground-based observations (systems similar to GMN cameras). The energies are usually accurate though, which is the most important thing for these bright events which saturate all other ground-based sensors, and that's what we all use in our papers.

Cue Avi Loeb and his undergrad student, theoretical astrophysics from Harvard. They found this object from 2014 on the public CNEOS list, noticed it's nominally interstellar, and published a pre-print in 2019 claiming it's >99% interstellar using a made up measurement precision. Of course, no journals wanted to touch it because people who had previous experience with the data set know how inaccurate it is, and you can't get your hands on the data because it's classified. So Avi starts pulling FOIA requests left and right, and the Space Force comes up with a document saying the measured speed is correct. They say nothing about the radiant nor do they say anything about the measurement precision. Amir claims that they got in touch with the analyst who originally measured the data, but we have no way to check their work and only have to take his word at face value. We simply can't do science by decree, no matter who signs the document. The data remains classified - for a good reason, as releasing the data would reveal too much information about these systems.

In the aftermath, even the NASA's head of planetary defense denied the accuracy of those claims: https://skyandtelescope.org/astronomy-news/u-s-space-force-releases-data-on-bright-fireballs/ From the looks of it (and the tone of the tweet), it appears that the Space Force had good intentions of helping out the scientific community and getting some good publicity in the process. But they made a terrible blunder in judgment and failed to check their science.

So in the end we are left with no extraordinary evidence for this extraordinary claim, and the search continues. However, the analysis they do in the pre-print is actually what one would do if good data was available. The theoretical approach is sound, but the practical experience is lacking.
There's also something else at play here with Avi, but I'll just leave a link to a relevant comic: https://www.smbc-comics.com/comic/2012-03-21

Cheers,
Denis
Hamish Barker
 

Thanks Denis for the thorough treatment. 

And the comic ... /* chef's kiss */

On Thu, Apr 14, 2022, 14:18 Denis Vida <denis.vida@...> wrote:
I was actually meaning to write something about this today, as I noticed this event reared its head again. It's interesting to read it from Amir's perspective.
The story behind it is long, but I'll try to summarize the key points.

Recording an interstellar meteor has been somewhat of a holy grail for meteor scientists. It would mean that we have direct evidence that other Solar Systems work the same as ours, and we would be able to use its direction to figure out something about our neighboring planetary systems. After 'Oumuamua was discovered, it raised more questions than answers (it had a very unusual shape and showed no activity). Borisov was actually a comet (as expected), but it was humongous (we expected something smaller).

If you look into any meteor orbit database, you will find a plethora of "interstellar" meteors. The problem is that if you look into any of them closely and really try to robustly determine if they really are interstellar, you will soon run into problems (there are plenty of papers on the topic). The problem is that meteor velocity is very hard to measure, and in certain configurations even a tiny error in velocity can mean a huge difference in the final orbit. And guess what, all "interstellar" meteors we have seen so far are right on that border and can go either way. The old adage (that Amir mentions) is that "extraordinary claims require extraordinary evidence", which we simply don't have.

The CNEOS website (https://cneos.jpl.nasa.gov/fireballs/) lists bright fireballs that top secret US government sensors (spy satellites) observe from orbit. The utility of the website is simple - if there's a huge explosion in the atmosphere, they want the general public to know that it was not a nuclear weapon but a fireball. The final data product is public, they publish the time of the event, nominal velocity, radiant direction, and the total energy of the event (conveniently given in kilotons of TNT equivalent). The whole meteor and asteroid community monitors this website and we have learned over the years not to trust it. There are typos, some radiants can be off by as much as 40 degrees (!), and the velocities can also be quite off. We know this because we compared the measurements to high-accuracy ground-based observations (systems similar to GMN cameras). The energies are usually accurate though, which is the most important thing for these bright events which saturate all other ground-based sensors, and that's what we all use in our papers.

Cue Avi Loeb and his undergrad student, theoretical astrophysics from Harvard. They found this object from 2014 on the public CNEOS list, noticed it's nominally interstellar, and published a pre-print in 2019 claiming it's >99% interstellar using a made up measurement precision. Of course, no journals wanted to touch it because people who had previous experience with the data set know how inaccurate it is, and you can't get your hands on the data because it's classified. So Avi starts pulling FOIA requests left and right, and the Space Force comes up with a document saying the measured speed is correct. They say nothing about the radiant nor do they say anything about the measurement precision. Amir claims that they got in touch with the analyst who originally measured the data, but we have no way to check their work and only have to take his word at face value. We simply can't do science by decree, no matter who signs the document. The data remains classified - for a good reason, as releasing the data would reveal too much information about these systems.

In the aftermath, even the NASA's head of planetary defense denied the accuracy of those claims: https://skyandtelescope.org/astronomy-news/u-s-space-force-releases-data-on-bright-fireballs/ From the looks of it (and the tone of the tweet), it appears that the Space Force had good intentions of helping out the scientific community and getting some good publicity in the process. But they made a terrible blunder in judgment and failed to check their science.

So in the end we are left with no extraordinary evidence for this extraordinary claim, and the search continues. However, the analysis they do in the pre-print is actually what one would do if good data was available. The theoretical approach is sound, but the practical experience is lacking.
There's also something else at play here with Avi, but I'll just leave a link to a relevant comic: https://www.smbc-comics.com/comic/2012-03-21

Cheers,
Denis

On Wed, Apr 13, 2022 at 8:39 PM Ken Jamrogowicz via groups.io <ke2n=cs.com@groups.io> wrote:
maybe of interest

https://www.scientificamerican.com/article/spy-satellites-confirmed-our-discovery-of-the-first-meteor-from-beyond-the-solar-system/




Ken

Mark McIntyre
 

To echo Denis' remarks, an appreciable percentrage of matches in the UKMON database are 'hyperbolic' implying their origins are extrasolar. However closer examination invariably indicates that these are also the data with the lowest confidence, for example only two stations, with a narrow convergence angle, at extreme range, etc.

On 14/04/2022 05:32, Hamish Barker wrote:

Thanks Denis for the thorough treatment. 

And the comic ... /* chef's kiss */

On Thu, Apr 14, 2022, 14:18 Denis Vida <denis.vida@...> wrote:
I was actually meaning to write something about this today, as I noticed this event reared its head again. It's interesting to read it from Amir's perspective.
The story behind it is long, but I'll try to summarize the key points.

Recording an interstellar meteor has been somewhat of a holy grail for meteor scientists. It would mean that we have direct evidence that other Solar Systems work the same as ours, and we would be able to use its direction to figure out something about our neighboring planetary systems. After 'Oumuamua was discovered, it raised more questions than answers (it had a very unusual shape and showed no activity). Borisov was actually a comet (as expected), but it was humongous (we expected something smaller).

If you look into any meteor orbit database, you will find a plethora of "interstellar" meteors. The problem is that if you look into any of them closely and really try to robustly determine if they really are interstellar, you will soon run into problems (there are plenty of papers on the topic). The problem is that meteor velocity is very hard to measure, and in certain configurations even a tiny error in velocity can mean a huge difference in the final orbit. And guess what, all "interstellar" meteors we have seen so far are right on that border and can go either way. The old adage (that Amir mentions) is that "extraordinary claims require extraordinary evidence", which we simply don't have.

The CNEOS website (https://cneos.jpl.nasa.gov/fireballs/) lists bright fireballs that top secret US government sensors (spy satellites) observe from orbit. The utility of the website is simple - if there's a huge explosion in the atmosphere, they want the general public to know that it was not a nuclear weapon but a fireball. The final data product is public, they publish the time of the event, nominal velocity, radiant direction, and the total energy of the event (conveniently given in kilotons of TNT equivalent). The whole meteor and asteroid community monitors this website and we have learned over the years not to trust it. There are typos, some radiants can be off by as much as 40 degrees (!), and the velocities can also be quite off. We know this because we compared the measurements to high-accuracy ground-based observations (systems similar to GMN cameras). The energies are usually accurate though, which is the most important thing for these bright events which saturate all other ground-based sensors, and that's what we all use in our papers.

Cue Avi Loeb and his undergrad student, theoretical astrophysics from Harvard. They found this object from 2014 on the public CNEOS list, noticed it's nominally interstellar, and published a pre-print in 2019 claiming it's >99% interstellar using a made up measurement precision. Of course, no journals wanted to touch it because people who had previous experience with the data set know how inaccurate it is, and you can't get your hands on the data because it's classified. So Avi starts pulling FOIA requests left and right, and the Space Force comes up with a document saying the measured speed is correct. They say nothing about the radiant nor do they say anything about the measurement precision. Amir claims that they got in touch with the analyst who originally measured the data, but we have no way to check their work and only have to take his word at face value. We simply can't do science by decree, no matter who signs the document. The data remains classified - for a good reason, as releasing the data would reveal too much information about these systems.

In the aftermath, even the NASA's head of planetary defense denied the accuracy of those claims: https://skyandtelescope.org/astronomy-news/u-s-space-force-releases-data-on-bright-fireballs/ From the looks of it (and the tone of the tweet), it appears that the Space Force had good intentions of helping out the scientific community and getting some good publicity in the process. But they made a terrible blunder in judgment and failed to check their science.

So in the end we are left with no extraordinary evidence for this extraordinary claim, and the search continues. However, the analysis they do in the pre-print is actually what one would do if good data was available. The theoretical approach is sound, but the practical experience is lacking.
There's also something else at play here with Avi, but I'll just leave a link to a relevant comic: https://www.smbc-comics.com/comic/2012-03-21

Cheers,
Denis

On Wed, Apr 13, 2022 at 8:39 PM Ken Jamrogowicz via groups.io <ke2n=cs.com@groups.io> wrote:
maybe of interest

https://www.scientificamerican.com/article/spy-satellites-confirmed-our-discovery-of-the-first-meteor-from-beyond-the-solar-system/




Ken

tegla hunter
 

Hi,

Has the GMN captured an interstellar meteor?
Is it possible to determine the interstellar origin of a meteor based on the data uploaded and made publicly available on globalmeteornetwork.org?
Mark McIntyre
 

Denis answered this question earlier in this thread. (on Apr 13th). Worth reading his comments. 

On 21/07/2022 02:08, tegla hunter wrote:

Hi,

Has the GMN captured an interstellar meteor?
Is it possible to determine the interstellar origin of a meteor based on the data uploaded and made publicly available on globalmeteornetwork.org?

David Rollinson
 

Mark McIntyre
 

Avi Loeb has somewhat wild theories in respect of various meteoroids' origins.  Meteor science is quite far of his specialty (he's a cosmologist) and i believe he's significantly misinterpreting the data.  As for the chance of it being an alien artefact, sorry but he's just making that up to get his fishing trip funded. 

And the chances of dredging up an actual fragment of that meteor from the seabed? Heck, we struggle to find them on dry land !!  If they retrieve anything, it'll be a completly unrelated fragment of a bog standard iron meteor which tehy will doubtless claim is alien...

See this detailed debunking from last year
https://www.imcce.fr/recherche/equipes/pegase/hypermeteor

and also on this forum:
https://globalmeteornetwork.groups.io/g/main/message/7084


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