
Rosetta Probe Discovers Organic Molecules on Comet - ohaal
http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-12176/#/gallery/17219
======
ihnorton
The underlying data here comes from the Ptolemy instrument, a gas
chromatograph mass-spectrometer (ion trap, in this case) which can measure
ratios of molecules in a range of 14 to 140 Da. (It might also be able to
identify somewhat larger species by inducing fragmentation and measuring the
resulting pattern of smaller molecules within the effective mass range, but I
haven't found if this capability was included).

Some more info here:
[http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1937.pdf](http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1937.pdf)

and:
[http://sci.esa.int/rosetta/31445-instruments/?fbodylongid=89...](http://sci.esa.int/rosetta/31445-instruments/?fbodylongid=896)

The instrument has its own Twitter feed, of course:
[https://twitter.com/philae_ptolemy](https://twitter.com/philae_ptolemy)

~~~
happyscrappy
Apparently the data is from COSAC not Ptolemy. The drill deployed but did not
get a sample.

[https://twitter.com/erichand/status/534413817040867328](https://twitter.com/erichand/status/534413817040867328)

Edit: Changed Rosetta to COSAC.

~~~
InclinedPlane
The article very clearly indicates the data is from COSAC, an instrument on
the lander. It also indicates that the sampling came from the "atmosphere" of
the comet rather than drilling.

~~~
ihnorton
Indeed, good catch - that wasn't in the originally-linked article and I
completely overlooked COSAC when looking up the instruments. So here is some
info on COSAC:

[http://www.mps.mpg.de/1979406/COSAC](http://www.mps.mpg.de/1979406/COSAC)

It is _also_ a GC-MS, but rather than an ion trap, it is a time-of-flight
analyzer with a much higher mass range (up to 1500 Da in the widest mode). It
is neat to have two mass specs on a single relatively small probe. They are
intended to be complementary, as discussed here (briefly, PTOLEMY is designed
to measure isotope ratios and the COSAC TOF is designed for organics as it can
measure chirality with dual GC columns, and also with a much higher mass
range):

ftp://ftp.iwf.oeaw.ac.at/pub/schwingenschuh/ROSETTA_Konrad/Lander/ulamec2007-pdf-
Capabilities%20of%20Philae,%20the%20Rosetta%20Lander%20-space-science-rev.pdf

[edit: for anyone else interested in mass-spec, I found some slides with an
overview of MS instruments on previous probes - I was familiar with several,
but there have been many more than I realized:
[http://jfsm2012.sciencesconf.org/conference/jfsm2012/pages/C...](http://jfsm2012.sciencesconf.org/conference/jfsm2012/pages/C10.pdf)]

------
ealloc
Personally I think the idea that life/prebiotic soup came to earth on a comet
is suspect, for the reasons explained in these blog posts and the links
therein:

[http://sandwalk.blogspot.ca/2011/11/nasa-confusion-about-
ori...](http://sandwalk.blogspot.ca/2011/11/nasa-confusion-about-origin-of-
life.html)

[http://sandwalk.blogspot.com/2009/04/can-watery-asteroids-
ex...](http://sandwalk.blogspot.com/2009/04/can-watery-asteroids-explain-why-
life.html)

Two problems with the 'organic asteroid' theory are the 'racemization problem'
(how to explain why life only uses L isomers rather than both the L and D
isomers present in meteorites), and the fact that the amount of organic matter
in meteors is tiny. Compare that to the opportunities for life to arise on
earth in its diverse chemical environments.

See the calculations by Jeffrey Bada discussed in the second link.

~~~
nitrogen
It's possible that there's no reason life chose L or D isomers, but choosing
one and sticking to it was advantageous (I use the word "choose" loosely
here).

~~~
bduerst
Abiogenesis is one of those things where there is way more speculation than
evidence. Some speculation says that it is because the molecular machinery
maintenance to handle both would be twice as taxing for organisms.

Of course, having the reverse isomer molecules would be advantageous against
predators (who couldn't digest it) and a boon to natural selection.

Like I said, plenty of speculation to be had.

~~~
SixSigma
Not being digested doesn't stop you getting killed.

~~~
bduerst
By predators it does. Unless you're chomping on some raw grass right now ->
then I stand corrected.

~~~
SixSigma
I just ate some bread

~~~
bduerst
Sounds digestible _and_ non-sequitur.

~~~
delecti
I believe what they're getting at is that it's possible to do things to other
species which leaves them digestible when they weren't initially. For example,
human cooking, bird gizzards, cows chewing their cud, or rabbits eating their
feces to give a second pass of digestion.

~~~
bduerst
You talk about cooking meat, but we still have enzymes in our stomachs (e.g.
pepsinogen) that only digest L-peptide chains. As a predator, you do not
digest D-peptide chains.

\- It is analagous to eating raw grass.

\- It is not analgous to eating processed/cooked grains, hence it is non-
sequitur.

\- It is a matter of biochemistry, not culinary arts.

I gave the original speculation as an example of there being too much
speculation around abiogenesis and evolution. This discussion proves it.

------
christiangenco
Oh interesting:

> Once the rechargeable secondary battery has been warmed by sunlight again,
> Philae will restart and the DLR LCC team will take their places at the
> control consoles again.

This is the first I've heard that Philae can wake back up. I was under the
impression that it had no solar capabilities whatsoever, and that the battery
was the only power it had available.

~~~
yason
I've understood it has solar panels. But what would be the reason they didn't
put a nuclear battery on board? That would work for years.

If the direct output power of the nuclear battery was too low, it could still
be used to charge the rechargeable battery until it can make the lander do
work again for a few hours/days.

~~~
skywhopper
Nuclear batteries are 1) heavier, 2) more expensive, 3) politically
complicated.

~~~
Someone1234
Atomic batteries aren't really controversial or politically sensitive and have
been used to great effect by many nations involved in space travel.

There's some problem with Tritium expose if the craft exploded on launch but
those haven't really stopped it usage.

~~~
adestefan
The issue is getting the plutonium.

~~~
virtue3
nasa almost used up the last bits of our reserves of it for the last mars
lander.

Thankfully it appears that the united states department of energy is re-
visiting generating plutonium-238 for NASA:

[http://en.wikipedia.org/wiki/Plutonium-238#United_States_sup...](http://en.wikipedia.org/wiki/Plutonium-238#United_States_supply)

~~~
protomyth
Yet another reason to build thorium reactors since the "waste product" is
PU-238.

------
seccess
"Scientists are analyzing the data to see whether the organic compounds
detected by Philae are simple ones—such as methane and methanol—or a more
complex species such as amino acids"

I feel like there is a big difference between finding methane and finding
amino acids on the comet. Surely, finding methane isn't all that interesting.

~~~
kileywm
It would have interesting implications if it was produced by microorganisms. I
don't know enough to comment further, but I'm guessing that's what the article
was suggesting.

~~~
fsloth
Organic compounds are just molecules that have carbon atoms in them. You don't
need anything that is 'living' to produce them.

All life we have discovered on earth is based on carbon. So, finding these
building blocks of life in space is interesting because it is solid proof you
don't need to be on earth to produce them (something that might or might not
seem intuitively obvious but in science you can't use intuition as proof, only
as a guide). However, while making it a tiny bit more likely, it does not mean
anything is alive out there.

------
codeulike
Organic meaning, in this case, organic chemistry, i.e. stuff containing
carbon. Perhaps hydrocarbons. But it doesn't mean 'life'.

------
mkriss
You can access Wallstreet journal articles by searching title in google (
because if referal is from google then article is free )

------
grecy
We hearing that hopefully when it warms up and gets closer to the sun it will
wake up and start transmitting again.

Do they have an estimate of when it will be destroyed because it's too close
to the sun?

~~~
codeulike
comets go round the sun, not into it

~~~
privong
> comets go round the sun, not into it

But that does not mean all comets survive their close approach to the Sun.
Some, such as the sungrazing comets[0], come quite close to the surface and
can be destroyed by their encounters with the Sun.

As jnevill points out, this particular comet's orbit does not take it closer
to the Sun than the Earth's distance from the Sun. The comet is on a ~6yr
orbit, I believe, and so should survive for a long period of time.

[0]
[https://en.wikipedia.org/wiki/Sungrazing_comet](https://en.wikipedia.org/wiki/Sungrazing_comet)

------
ludoo
"according to the German agency" I was under the impression it's a European
agency...

~~~
Someone
The "Lander Control Center" is German (Deutsches Zentrum für Luft- und
Raumfahrt. See
[http://en.m.wikipedia.org/wiki/German_Aerospace_Center#Curre...](http://en.m.wikipedia.org/wiki/German_Aerospace_Center#Current))

------
gtirloni
Google redirect without paywall:
[https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&c...](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCEQqQIwAA&url=http%3A%2F%2Fonline.wsj.com%2Farticles%2Frosetta-
probe-directly-discovers-organic-molecules-on-
comet-1416256078&ei=TXZrVIfBEY3daLOOgeAN&usg=AFQjCNG59ouzNU_aXv7JBhhdGm4bBDCK5Q&sig2=0BaHL0tkVGarc5Hn7eEzNA&bvm=bv.79908130,d.d2s)

~~~
piyush_soni
Thanks. Just a note to others, if you have already opened the link 'with' the
paywall, even this might not work. Just open this link in another browser.

~~~
delucain
Chrome's incognito mode is a good solution for this too.

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dz0ny
Source:
[http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151...](http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-12176/#/gallery/17219)

~~~
trose
Thank you! It should be HN policy to not post paywall sites IMO

~~~
davidw
We post links to products that cost money, though, no? Journalists need to eat
too. Usually it takes entire milliseconds for someone to post other links,
anyway. Or you can always sneak around the paywall.

In this case I don't mind an article that has a bit more science bias rather
than 'mainstream', so the DLR link is nice.

~~~
pbhjpbhj
> _In this case I don 't mind_ //

Just to confirm you've personally paid for access to this content?

~~~
Kiro
Why do you ask?

~~~
pbhjpbhj
Well the opinion that you "don't mind paying" for something only really means
anything if you actually pay for it (or pay for something similar). If you
"don't mind paying" but you're getting it free (eg via your workplace or some
other way) then that opinion seems pretty void.

------
irollboozers
The fact that exciting scientific discoveries like this are being presented on
WSJ behind a paywall is absurd. Science on the internet is going to be
dramatically different in 10 years than it is right now...

~~~
jonnathanson
It's inconvenient for us, but I wouldn't necessarily call it "absurd." The
Wall Street Journal is not a 501(c). It's either this, or a flurry of
intrusive ads. (Or a subscription upsell, but I digress). Different
publications pick their poison differently. But someone's gotta pay for
_something_.

Besides, paywalls aren't hard to circumvent. Someone usually posts a redirect
within minutes of these articles' being linked here.

~~~
baddox
It's absurd in the context of social norms and expectations. A restaurant
isn't a 501(c) either, but I would call it absurd if they charged a customer
to use the restroom.

~~~
jonnathanson
Respectfully, I'm not sure I follow the analogy. A restaurant's core business
is serving food, and a restaurant charges for food. The Journal's core
business is journalism, and it charges for journalism. Content isn't the
"restroom" of the WSJ's business model.

As I've stated in a comment further down this tree, I don't like paywalls. I
think they're an inefficient and suboptimal means of monetizing content. A
paywall is basically a tax on readers who aren't savvy enough to bypass it. If
you look at the economics of a paywall, it's basically monetizing the
intersection of two sets of people: 1) the set of all people who really want
to read the WSJ, and 2) the set of all people who can't get around a paywall
when they encounter one. This intersection cohort -- call it "People who like
WSJ and can't navigate paywalls" \-- is probably a decent size, but it leaves
a lot of would-be customers on the table. At the same time, the paywall
hampers distribution and creates a bad user experience. It's an
unsophisticated way to monetize content. That said, I don't find it "absurd."
Bad, sure. Annoying, absolutely. "Absurd," no. Nor do I find absurdity in the
premise that the WSJ should attempt to monetize its content.

~~~
eru
Can't, or don't want the hassle.

------
dang
Url changed from [http://online.wsj.com/articles/rosetta-probe-directly-
discov...](http://online.wsj.com/articles/rosetta-probe-directly-discovers-
organic-molecules-on-comet-1416256078) because that one is behind a paywall
and this one is a more original source.

