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View Full Version : Nitrogen Would Indicate Extraterrestrial Life



Fraser
2006-May-06, 03:40 AM
SUMMARY: When searching for life, most researchers have been hunting the Solar System for signs of liquid water; past and present. But geobiologists from the University of Southern California think that more effort should be spent looking for evidence of nitrogen. Since nitrogen isn't a major component in rocks and minerals but an essential component of life, any concentration of this element would strongly indicate life's fingerprint. They hope that next generation spacecraft will have advanced nitrogen sampling capabilities.

View full article (http://www.universetoday.com/am/publish/nitrogen_extraterrestrial.html)
What do you think about this story? post your comments below.

Dragon Star
2006-May-06, 03:45 AM
But isn't Nitrogen found all over the place?:think:

g3wzr
2006-May-06, 02:50 PM
Venus has about the same amount of nitrogen as the Earth has, so is that now evidence for life (presumably in the past) on Venus?

antoniseb
2006-May-06, 03:09 PM
There's no shortage of Nitrogen on Titan either, but the story is implying that Nitrogen (especially organic nitrogen, such as in amino acids) is necessary, but not sufficient to demonstrate life. The lack of nitrogen is evidence for no life.

Dragon Star
2006-May-06, 03:42 PM
So they are only using it as evidence to NOT support life when a place where life could be is found is found...

makes sense.

Jerry
2006-May-08, 01:36 PM
Fixed nitrogen is rather rare. While water, carbon and nitrogen are everywhere, nitrogen as amino acids would be a much clearer indicator that life may exist on the planet or moon- at least the forms we are familiar with, exist.

Eroica
2006-May-08, 03:53 PM
There's no shortage of Nitrogen on Titan either, but the story is implying that Nitrogen (especially organic nitrogen, such as in amino acids) is necessary, but not sufficient to demonstrate life. The lack of nitrogen is evidence for no life.
That makes sense, but that's not what the article says:


Since nitrogen isn't a major component in rocks and minerals but an essential component of life, any concentration of this element would strongly indicate life's fingerprint ... any substantial organic nitrogen deposits found in the soil of Mars, or of another planet, likely would have resulted from biological activity.
:think:

TheBlackCat
2006-May-08, 04:33 PM
Nitrogen is the most common element in the universe found elemental form next to helium, any planet with a substantial atmosphere should have significant amounts of nitrogen. It might be a decent way of detecting rocky planets with an atmosphere since gas giants have much higher hydrogen levels, but that is all you can tell. Now a planet with high nitrogen levels but low CO2 or high elemental oxygen levels would definitely be something of interest, since anywhere with nitrogen would be expected to also have CO2 but not elemental oxygen without biological influences.

Even with fixed nitrogen, I would expect it to be much too hard to detect the very small amounts of fixed nitrogen even in a biological environment that close to a star, especially considering fixed nitrogen is mostly locked up in organisms or in the soil and thus not in the atmosphere in any significant degree. I would be suprised if we could detect the spectrographic signature of fixed nitrogen inside organisms from this distance with a star in the way. Detecting relative nitrogen, CO2, and elemental oxygen levels would be much easier.

Yet another clue would be ozone, which is ultimately derived from elemental oxygen which does not occur in nature in any significant amount. Detecting the presence of atmospheric ozone would be a very strong indicator of life.

This issue, of course, is getting the spectrographic signature of a planet that close to a star.

Astromood
2006-May-11, 01:34 PM
I thought hydrogen was the most abundant element in the Universe and helium second. But that doesn't sound right. There is LOTS of nitrogen on Titan but it's WAY too cold to support any life as we know it. Of course there could be a subterranian ocean or something.

antoniseb
2006-May-11, 02:00 PM
Hi Astromood, welcome to the BAUT forum.

I think TheBlackCat was trying to rule out Hydrogen on some grounds that it wasn't normally found in the H2 molecular form. I'm not sure that TBC is right, but Nitrogen IS very common. As noted above, Titan does have lots of it, but Nitrogen containing molecules, such as amino acids are necessary but not sufficient for life.

Ilya
2006-May-15, 12:03 AM
I think TheBlackCat was trying to rule out Hydrogen on some grounds that it wasn't normally found in the H2 molecular form.
If you look only at the Solar System, and only at H2 molecules -- excluding ionized hydrogen in the Sun, all hydrogen compounds, and metallic hydrogen inside giant planets, -- then neutral helium may squeak by as the most common elemental molecule. But in Universe at large, hydrogen wins hands down. Giant molecular clouds dwarf all the planets in the galaxy combined, and they are mostly neutral H2.

trinitree88
2006-May-15, 12:21 AM
If you look only at the Solar System, and only at H2 molecules -- excluding ionized hydrogen in the Sun, all hydrogen compounds, and metallic hydrogen inside giant planets, -- then neutral helium may squeak by as the most common elemental molecule. But in Universe at large, hydrogen wins hands down. Giant molecular clouds dwarf all the planets in the galaxy combined, and they are mostly neutral H2.

Ilya. nitpik. Helium is not molecular...it's monatomic....and very happy that way.

Ilya
2006-May-15, 01:32 PM
Helium is a monatomic molecule.