A scientist said that comets contain organic material.

What exactly does 'organic' mean?

Hello.

From NASA:
"Organic-  Organic means of or originating from carbon compounds."
http://neurolab.jsc.nasa.gov/glossnr.htm

"  Organic chemicals (also known as hydrocarbons) contain carbon
bonded to hydrogen (some also contain other elements).  Because of the
unique bonding properties of carbon, there are millions of different
organic chemicals.  Each one has unique properties.  There are organic
chemicals that make up your hair, your skin, even your fingernails. 
All life as we know it is made up of organic compounds.  "
http://web.jjay.cuny.edu/~acarpi/NSC/10-organic.htm

'"Organic Material" means a chemical compound of carbon, excluding
carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or
carbonates, and ammonium carbonate.'
source: EPA
https://yosemite.epa.gov/R8/R8Sips.nsf/0/2feba70047f8e9e287256b7d0058301f?OpenDocument

"Organic material means anything made up of carbon, hydrogen,
nitrogen, and oxygen. All living things are made mostly of these four
substances. Sugar, alcohol, and methane are also organic compounds."
http://cse.ssl.berkeley.edu/segwayed/lessons/cometstale/make_script.html

"Astronomers have identified some 60 compounds in interstellar clouds,
three-fourths of which are organic. ("Organic" means that the compound
is carbon-based, but not necessarily biological in origin.) "
http://www.spaceflightnow.com/stardust/031230science.html

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search strategy:
"organic means" carbon 

I hope this helps.

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Request for Answer Clarification by rambler-ga on 06 Dec 2005 08:19 PST

Thank you for the definitions that you provided.  Would you please
clarify the following:

(1) Organic compounds contain four elements:  carbon, hydrogen,
nitrogen, and oxygen.  Correct?
(2) Carbon monoxide, carbon dioxide, carbonic acid, metallic carbides
or carbonates, and ammonium carbonate are NOT organic.  Why not?
(3) Sugar, alcohol, and methane are also organic compounds.  Why? (Do
they contain carbon, hydrogen, nitrogen, and oxygen?)
(4) Why is it significant that comets contain organic compounds?

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Clarification of Answer by juggler-ga on 06 Dec 2005 13:25 PST

(1) Organic compounds contain four elements:  carbon, hydrogen,
nitrogen, and oxygen.  Correct?

"The vast majority of organic compounds contain Carbon, Hydrogen,
Oxygen and Nitrogen."
http://www.krysstal.com/organic.html

Technically, though, "organic" only requires carbon and hydrogen.

"The simplest Organic compounds are made up of only Carbon and
Hydrogen atoms only."
http://www.krysstal.com/organic.html


(2) Carbon monoxide, carbon dioxide, carbonic acid, metallic carbides
or carbonates, and ammonium carbonate are NOT organic.  Why not?

Carbon compounds are considered "inorganic" (not organic) if they do
not contain carbon bound to hydrogen.
See:
http://www.madsci.org/posts/archives/dec96/847927874.Bc.r.html
http://antoine.frostburg.edu/chem/senese/101/inorganic/faq/what-is-inorganic-carbon.shtml


(3) Sugar, alcohol, and methane are also organic compounds.  Why? (Do
they contain carbon, hydrogen, nitrogen, and oxygen?)

They all contain carbon bonded to hydrogen.  


Methane is one carbon atom bonded to four hydrogen atoms.
"The simplest organic chemicals, called hydrocarbons, contain only
carbon and hydrogen atoms; the simplest hydrocarbon (called methane)
contains a single carbon atom bonded to 4 hydrogen atoms"
http://www.visionlearning.com/library/module_viewer.php?mid=60&l=&c3=

Sugar contains carbon, hydrogen and oxygen.
http://www.wwnorton.com/chemistry/overview/ch12.htm#sugar

Alcohols contain carbon bonded to hydrogen and oxygen.
http://www.wwnorton.com/chemistry/overview/ch12.htm#alcohol



(4) Why is it significant that comets contain organic compounds?

It's significant because comets may have brought organic materials to
earth and thus played a part in the origin of life.

?People have long suspected that comets played a role in the origin of
life. No one really knows this because no one knows how life began.
But we do know that comets are the most carbon-rich materials in the
solar system, and we know they?re full of organic compounds and they
fall on the Earth all the time. Even now we have tens of thousands of
tons of comet particles landing on the Earth every year,?

?Comets are a vehicle that brings organic materials to the Earth. Many
of the carbon atoms in our bodies were in comets early in the history
of the solar system. So one of the bylines of the Stardust mission is
that we are stardust. Our bodies are actually made of stardust.?
See:
http://depts.washington.edu/uweek/archives/1999.02.FEB_04/article1.html

Thank you so much for providing an answer and clarification!

Rambler, your request for clarification is actually questions that
should be posted anew. Juggler has done a typically fine job on a
question priced as this one is.

I will take a quick whack at number two-- does carbon monoxide have
hydrogen? Is the nitrogen in ammonium carbonate bound to the carbon?

As for number four-- you should be able to answer that with about
thirty seconds worth of thinking. Go to it, lad!

Organic chem is a fascinating field. I don't ever recall sleeping each
time I had to take a class in it... and there were a lot!

Four Bronx cheers for a rather unhelpful comment.

Rambler:
Thank you for the tip.
-juggler

Originally "organic" chemicals were those that came from living
things, and it was thought that organic chemicals could not be made by
non-living processes (vitalism).  Today, the distinction is much less
clear.  "Organic" chemicals (for example, methane) can be made by
non-living processes, while "inorganic" chemical (for example, sodium
chloride) can be necessary for life.