
'Oumuamua could be a shard from a dead planet - egfx
https://www.nationalgeographic.com/science/2020/04/perplexing-interstellar-object-starts-revealing-its-secrets/
======
robocat
Has National Geographic gone downhill since the media part became
[https://en.wikipedia.org/wiki/National_Geographic_Partners](https://en.wikipedia.org/wiki/National_Geographic_Partners)

This reads like “Disney” science: take some facts and spin them to be
entertainment. I thought the same of this article where I thought the
reporting was twisting facts to make a headline:
[https://www.nationalgeographic.com/science/2020/04/lost-
your...](https://www.nationalgeographic.com/science/2020/04/lost-your-sense-
of-smell-it-may-not-be-coronavirus/)

~~~
astro123
I read a lot of astronomy journalism that I think is absolutely awful (one of
the main reasons I made this account was to point out garbage
articles/comments). I actually think that this is pretty good.

It mostly follows the paper (here's what looks like an earlier version of this
paper that is easily available [1]), doesn't engage in too much hyperbole,
isn't publicizing something widely outside of the consensus.

Disclaimer that I don't work on planetary formation/dynamics so am not an
expert on this, but still, pretty impressed.

[1]
[https://www.hou.usra.edu/meetings/apophis2020/pdf/2018.pdf](https://www.hou.usra.edu/meetings/apophis2020/pdf/2018.pdf)

~~~
robocat
Here’s a 2019 preprint that concludes “We show that cigar-shaped models suffer
from a fine-tuning problem and have only 16 per cent probability to produce
light curve minima as deep as the ones present in `Oumuamua's light curve.
Disc-shaped models, on the other hand, are very likely (at 91 per cent) to
produce minima of the required depth.”

[https://arxiv.org/abs/1906.03696](https://arxiv.org/abs/1906.03696)

So it seems like there is still a lot of conjecture involved... Yet the
National Geographic article misleads by showing an artists impression
(pictures are truthy) while treating the elongated shape as fact on every line
(the alternate disc model was also mentioned in original paper trying to
deduct the shape, although the paper concluded it was less likely). Poor
reporting IMHO.

I am not an astrophysicist, but this is the second Nat Geo article that I’ve
read recently that has really failed my good reporting sniff test. Edit:
failed to meet the high standards I expect from Nat Geo.

~~~
laumars
Did you read to the end? The article does actually make that point:

> _But [Bannister] and Laughlin introduce a new wrinkle to the mystery:
> They’re skeptical that ‘Oumuamua is actually a cigar-shaped object, pointing
> to a paper published last summer that revisited the original observations of
> the object. The newer analysis concludes that ‘Oumuamua may actually have a
> pancake-like shape—a shape that Bannister likens to an overstuffed pita,
> similar to an object in the outer solar system called MU69, or Arrokoth._

I get your point that the article doesn't promote the significance of the
disc-shape analysis enough however my takeaway from the article wasn't that it
was claiming the origin of Oumuamua was solved but rather new research has
identified potential scenarios where cigar-shaped objects could be naturally
created (research which was spurred on by the discovery and mystery of
Oumuamua).

If that was what the article intended to cover then it doesn't make sense to
cover the disc-shaped analysis extensively throughout the article however for
clarity the mention of Oumuamua probably should also have been demoted in at
least the title. Sadly I think there's little chance of putting click-bait
headlines back in the proverbial genie bottle.

------
corysama
I realize an iPhone 6+ is an old phone. But, this is a simple page with some
simple text and simple images that is working so hard to track me that it is
completely unreadable even though they really want me to read it.

~~~
ErikAugust
Here you go, 4 MB to 25 KB:
[https://beta.trimread.com/articles/11029](https://beta.trimread.com/articles/11029)

~~~
bottled_poe
I love it! But it must be breaching copyright/terms etc...

~~~
fnord123
Maybe it fits under fair use as critique. It's a critique showing the
bloatedness of the original article. And it's only using 0.6% (0.006) of the
original to make its point.

~~~
crispyporkbites
> it's only using 0.6% (0.006) of the original

When you think about it this way it’s clearly fair use.

~~~
pbhjpbhj
Usually copyright laws refer to a substantial part of a work, it maybe be 0.6%
of the delivered web page, but it's 100% (presumably) of the article. The
article counts separately as a work (and each image within an article could
count as a separate work, there are conditions on that). But, in any case if
all the textual context was copied that's still substantial. Interpreting
things in a purely numerical way like that would be clearly ridiculous.

Such gotchas don't work in law in general (in my very limited experience).

~~~
fnord123
Gotchas absolutely do work in this way in law. You just need to be willing to
fight it in court.

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nathell
Nitpick: it's ʻOumuamua, not 'Oumuamua. The initial letter is the ʻokina
(U+02BB), representing a glottal stop.

[https://en.wikipedia.org/wiki/%CA%BBOkina](https://en.wikipedia.org/wiki/%CA%BBOkina)

~~~
lordgrenville
There was a discussion the other day about whether it's bad when HN gets
derailed from TFA by incredibly minor details. I'm in favour of the tangents,
which can often be more interesting than the primary topic - as is the case
(for me) with your comment. Thanks for sharing :)

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DonHopkins
How is Oumuamua even pronounced?

It's the funniest sound I ever heard! I can't understand a single word. Is he
serious or is he playing?

[https://www.youtube.com/watch?v=eHvhRenwbb0](https://www.youtube.com/watch?v=eHvhRenwbb0)

~~~
TLightful
[https://www.youtube.com/watch?v=UwUM4t4GOcY](https://www.youtube.com/watch?v=UwUM4t4GOcY)

Not difficult at all.

------
LatteLazy
Could be, could be something else, let's speculate widely!

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bufferoverflow
It "could be" almost anything. Billions of years, hundreds of billions of
stars in our galaxy alone.

------
Papirola
Metal Hurlant...

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mihcsab
why is this upvoted?

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fizixer
I don't see how this is a new discovery. That line of thinking was pretty much
the implicit null hypothesis.

The question at that time was, is it something more than that? and that's what
made it interesting.

~~~
goodcanadian
We didn't know how to make shards in the presumed shape of `Oumuamua,
naturally. There is now a plausible model of planets being ripped apart by
tidal forces which can result in such shapes.

------
aaron695
I'd still like a good take down of why this couldn't be from our solar system.

Seems highly unlikely these crazy 'from outside the solar system' ideas are
likely.

This meme spreads well, but that to me means there is far more chance it is
not true. The fact no one questions it also seems suspicious.

~~~
astro123
The argument is actually really really simple. If it started from within the
solar system, it would not (barring some three body interaction) have enough
energy to escape. But, we know from observations that it does have enough
kinetic energy to escape. There are two options,

1\. It may have stolen some energy from another object (an accidental gravity
assist), but we know that it didn't come close enough to anything big on its
way though.

2\. It came from outside the solar system and so entered with some velocity,
and therefore will leave with roughly the same velocity it came in with.

We have well known mechanisms to eject objects from star systems so it isn't
crazy to have things passing through. No-one questions it because high school
level physics is enough to show why it is the only reasonable explanation.

~~~
aaron695
> We have well known mechanisms to eject objects from star systems so it isn't
> crazy to have things passing through.

We know it's 'possible' for a tennis ball to go through a wall. But it's not
actually within the realms of the possible.

So I guess I still question the 'crazy' part. What are the mathematics here.

If a planet breaks into 5000000000000000 (Earth / Oumuamua) pieces how many
hit another solar system? I'd expect zero, but have no idea.

I think it's more likely 1. We missed the fact it went close to another body
or it's in a complicated gravity assist eons in the making.

~~~
btilly
See [https://www.space.com/43015-interstellar-visitor-oumuamua-
no...](https://www.space.com/43015-interstellar-visitor-oumuamua-not-that-
special.html) for the math.

But you're still focusing on the wrong thing. The idea of "a complicated
gravity assist" getting something going this fast in the Solar System is
laughable. The only thing in the Solar System heavy enough to do a gravity
assist on the necessary scale is the Sun itself, and it started nowhere near
the Sun.

~~~
aaron695
That link is great thanks.

For it to be real I'd expect billions of things passing through yearly, maybe
daily. For something as large as Oumuamua I'd intuitively expect millions or
billions of small rocks coming through.

"We find that such objects collide with the Sun once every 30 years, while
about 2 pass within the orbit of Mercury each year."

But I worry about anything like this talking in human years, like "30 years".
I'd expect every million years or millions a year when talking about the
universe.

I understand as our technology grows, first we find yearly events and then
improve. But the theoretical must make sense to me in non human timelines.

~~~
btilly
There could well be millions or billions of sand particle sized objects coming
through constantly.

The Solar System is big. Almost all of them will pass through and miss
everything. We literally have no way to notice them.

Incidentally we have spotted a second interstellar object.
[https://en.wikipedia.org/wiki/2I/Borisov](https://en.wikipedia.org/wiki/2I/Borisov)
is more what we were expecting them to look like.

