
Rosetta catches dusty organics - okket
http://blogs.esa.int/rosetta/2016/09/07/rosetta-catches-dusty-organics/
======
okket
Just a few days left for Rosetta, you might want to mark the date in your
calendar:

    
    
      On September 29, a rocket burn will essentially cancel out
      Rosetta's orbital motion around the comet, initiating a
      free fall from an altitude of 20 kilometers. The spacecraft
      will impact the comet at a speed of about 90 centimeters
      per second at 04:20 PDT / 07:20 EDT / 11:20 UTC / 13:20
      CEST, give or take 20 minutes. 
    

[http://www.planetary.org/blogs/emily-
lakdawalla/2016/0909102...](http://www.planetary.org/blogs/emily-
lakdawalla/2016/09091029-rosetta-end-of-mission-update.html)

(The rocket burn is on the 29th, the impact on the 30th, of course.)

~~~
celticninja
Is it possible the impact will affect trajectory of the comet?

~~~
symmetricsaurus
No, Rosetta is already in orbit around the comet. By the principle of
conservation of momentum the impact will not change the total momentum of the
system (comet plus spacecraft).

The changes in trajectory happens when the engines are used on the spacecraft.

~~~
dandelany
Would this still hold true if Rosetta were commanded to slam into the comet
hard enough for some of the impact debris to reach escape velocity? (Not
trying to nitpick your argument, it certainly holds true for the soft landing
case, but I'm curious how strong this axiom is)

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zengid
Can anyone comment on how significant this discovery is? Are we talking
unprecedented or has this been hypothesized for a while? Are the conditions on
such comets more conducive for organic molecule formation than the surface of
a planet or large moon might be?

~~~
lorenzhs
According to the article, they were expecting it:

 _From analyses of meteorites and laboratory simulations, the team was also
expecting to identify a wide diversity of organic material in Comet 67P /C-G,
ranging from very small molecules to heavy (or ‘high molecular weight’)
organics._

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the_duke
Organic =
[https://en.wikipedia.org/wiki/Organic_compound](https://en.wikipedia.org/wiki/Organic_compound)

~~~
lorenzhs
I doubt anyone would expect to find organically grown veggies on a comet. Not
sure what you're trying to say. Isn't it pretty clear that they're referring
to molecules containing carbon?

~~~
Practicality
There was a related discussion recently where "organic" in an article was
referring to life-forms. So it's good to clarify which organic is being
discussed.

Of course, if they found microbes on a comet this would be a much bigger
announcement.

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mdup
Genuine question: How do we know the organic compounds seen by Rosetta do not
come from Earth and were not brought by Rosetta itself?

~~~
giomasce
Usually spacecrafts like that are built in clean rooms and care is taken so
they are sterilized when sent to space. I have no specific answer, though.

~~~
ygra
This will be _especially_ true for instruments that are designed to find such
compounds. It would be fairly embarrassing to send the probe into space, only
to notice that apparently interplanetary space is full of organic compounds no
one else has ever seen ...

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CHsurfer
“These particles have remained pristine and untouched for billions of years
until they were released in the days or weeks before being ‘caught’ by
COSIMA,"

I hope they will release the particles back into the wild once they are done
with their analysis.

~~~
aokyler
I'm not against releasing the particle...but any specific reason you hope they
release them once back into the wild after?

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r0muald
Anyone could explain briefly what is the "stretch" theory or hypothesis that
is mentioned in the heated comments section to the blog post?

~~~
scardine
I can't - and hell, I barely understand anything they say - but the style
reminds me of how Asimov would picture an academic dialogue between two
rivals.

