
Is ‘Oumuamua an alien spacecraft? First scans show no signs of technology - pmoriarty
https://www.theguardian.com/science/2017/dec/14/is-oumuamua-an-alien-spacecraft-first-scans-show-no-signs-of-technology
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twic
Okay, so it's a stealth ship:

[http://toughsf.blogspot.com/2016/10/the-hydrogen-steamer-
ste...](http://toughsf.blogspot.com/2016/10/the-hydrogen-steamer-stealth-
spaceship.html)

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wasx
I'm kind of glad to hear that to be honest. It's already too far away from us
and going too fast for any spacecraft that could currently be built to reach
it. It would have been a very cruel joke if the first opportunity for
interaction with extra terrestrial intelligence flew past us so
unceremoniously.

Of course it's certainly disappointing that it isn't an alien spacecraft, but
would have been doubly so if it were and we missed our window of opportunity.

~~~
cantrip
I dunno I think if it were an alien spacecraft we should just keep our heads
low and not draw any attention to it. Our first window of opportunity might be
our last.

~~~
wasx
I've gotta disagree with you on this. Personally I think intelligent life is
probably very rare in the universe, the sheer number of factors that need to
go right for it to arise, and then the sheer number of factors that need to
_not_ go wrong for it to continue to exist mean any intelligent life out there
is probably going to find us way more valuable and worthy of co-operation and
interaction than say destruction of us for the measly resources of Earth, or
enslavement (although I guess enslavement could be possible).

I do also have faith in the "humanity" of any interstellar life that may exist
out there, after all a society based on oppression tends to be rife with
conflict, and societies rife with instability and conflict don't tend to last.
And in my view it would be very unsustainable for any life to maintain that
sort of conflict, and at the same time hope to extend a society out into the
universe.

Nothing ventured, nothing gained. I think it's worth the risk.

~~~
dv_dt
What if intelligent life is rare because at some point some other intelligent
life set up a systematic process of keeping the universe clear of it?

~~~
andrepd
You've been playing too much Mass Effect 2 :^)

~~~
dv_dt
I've actually never played any Mass Effect...

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netinstructions
They mentioned that they're scanning a frequency range from 1 to 12 GHz.

Why that range? And what if it's transmitting at 0.5 or 13 GHz, or 500 GHz?
Would that show up, just weaker or..?

~~~
rmonroe
As a radio-astronomer: 1\. Well, few radio-telescopes have instantaneous
bandwidth as wide as a factor of 12 -- they are usually optimal on a narrow
region, and therefore hoping that another group with instruments optimized for
lower/higher frequencies will do the job 2\. Lower frequencies require larger
antennas to achieve useful gain. It is more likely that they would go higher
than 500 MHz vs lower. Also, dispersion (correctable with a position solve)
and scattering (not correctable) eventually become problems with low enough
frequencies and long enough distances 3\. If we observe at the wrong
frequencies, it will most likely not show up. RF filtering and antenna
response will ensure that.

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everdev
What if it's shields are up?

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hprotagonist
"Plane change maneuvers are expensive"

~~~
yoodenvranx
I wish that book had a better ending.

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idbehold
Which book is that?

~~~
vanilla_nut
Seveneves, if I'm reading the OP correctly. By Neal Stephenson.

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bleke
First thing what I do if it is my spacecraft i will not send anything until
I'll far away enough to not be detected and probably won't point transmitter
to planet which are investigated (I know that signal can be reflected back
from cosmic debris, but who can send rock to other solar system won't have
problem to calculate signal path which doesn't point to us)

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jbob2000
Maybe it's the interstellar equivalent of throwing a rock at someone's window
to get their attention? An alien race could have used a gravitational
slingshot to send it our way.

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ceejayoz
Obviously, this indicates they're using technology far exceeding ours that's
undetectable to our sensors.

~~~
pmoriarty
It could also be just a dead spacecraft, than was once operational but is no
longer so. That could also be why it's tumbling now, whereas once it may have
flown in a more aerodynamic fashion.

~~~
0bfus
it's obvious what you're describing but just wanted to point out that
aerodynamic is a poor choice of words to describe an interstellar body :)

~~~
stcredzero
If it's tumbling to provide artificial gravity, then the crew needs something
like 8.94595e-7 g to feel comfortable.

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bitwize
Coming up next on the History Channel: Preliminary scans indicated 'Oumuamua
was just a lump of space rock. But could it be... a _derelict_ alien
spaceship?

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hbcondo714
Perhaps like the _derelict_ spacecraft discovered in Alien[1]. Check for a
warning signal!

[1]
[http://alienanthology.wikia.com/wiki/The_Derelict](http://alienanthology.wikia.com/wiki/The_Derelict)

~~~
bitwize
Or perhaps it's like the _Macross_ , so completely inert -- but set to go off
once the Zentraedi come around to investigate.

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emptybits
The article makes a much more limited claim than what the headline suggests:

"the search for alien signals has so far found nothing in the 1.7 to 2.6GHz
range"

Scanning continues.

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mirimir
> The cigar-shaped object ...

All they have is a light curve, right? No imaging, right?

If so, "cigar-shaped" is just speculation.

~~~
Sir_Cmpwn
It rotates, so its brightness changes over time. From examining this data they
can draw some conclusions about its shape.

~~~
mirimir
Sure, but "some conclusions" is a long way from "cigar-shaped".

~~~
Sir_Cmpwn
When a factual mistake is called out, it's probably better to do some research
instead of doubling down.

>The astronomers figured out its elongated shape when they noticed its
brightness varied when it rotated every 7.3 hours. When the asteroid’s long
side faced the Earth, more of its surface area could reflect sunlight, making
it more visible to us. And when the tip of the rock faced us, it was a very
dim point of light.

>“What we found was a rapidly rotating object, at least the size of a football
field, that changed in brightness quite dramatically,” planetary astronomer
Karen Meech, who led the University of Hawaii team, said in a statement. “This
change in brightness hints that ‘Oumuamua could be more than 10 times longer
than it is wide — something that has never been seen in our own solar system.”

Source: [https://www.pbs.org/newshour/science/a-cigar-shaped-
asteroid...](https://www.pbs.org/newshour/science/a-cigar-shaped-asteroid-
just-boomeranged-through-our-solar-system)

Statement from the team in Hawaii: [http://www.ifa.hawaii.edu/info/press-
releases/Oumuamua/](http://www.ifa.hawaii.edu/info/press-releases/Oumuamua/)

You would be surprised how much we can infer with p>0.05 based on information
that looks scarce from the outside. Much of what we know about the universe is
found from surprisingly simple sources.

~~~
mirimir
We'll never know.

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kmm
Maybe it's just one stage of a rocket that is slowing down?

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chisleu
Any headline with a question mark can be answered: no

~~~
chisleu
[https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...](https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headlines)

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Giorgi
it is on scout mission, invasion is now imminent

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kurheim
take me now. this world is too crazy for me. :(

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agumonkey
ego blow, we're not even probe worth

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sp332
There's only one apostrophe in the name. It's not quote marks.
[https://en.wikipedia.org/wiki/ʻOumuamua](https://en.wikipedia.org/wiki/ʻOumuamua)
Or to be really specific
[https://www.fileformat.info/info/unicode/char/02bb/index.htm](https://www.fileformat.info/info/unicode/char/02bb/index.htm)
"typographical alternate for U+02BD or U+02BF used in Hawai`ian orthography as
`okina (glottal stop)"

