[meteorite-list] Ammonia on Mars Could Mean Life

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Jul 15 13:33:58 2004
Message-ID: <200407151733.KAA27662_at_zagami.jpl.nasa.gov>

http://news.bbc.co.uk/2/hi/science/nature/3896335.stm

Ammonia on Mars could mean life
By Dr David Whitehouse
BBC News
July 15, 2004

Ammonia may have been found in Mars' atmosphere which some scientists
say could indicate life on the Red Planet.

Researchers say its spectral signature has been tentatively detected by
sensors onboard the European Space Agency's orbiting Mars Express craft.

Ammonia survives for only a short time in the Martian atmosphere so it
must be getting constantly replenished.

There are two possible sources: either active volcanoes, none of which
have been found yet on Mars, or microbes.

Excitement

"Ammonia could be the key to finding life on Mars," one US Space Agency
(Nasa) scientist told BBC News Online.

Spectral evidence of the gas was seen by the Planetary Fourier
Spectrometer (PFS) on Mars Express.

Professor Vittorio Formisano, principal investgator for the instrument,
is expected to release details of new findings from the PFS at an
international conference being held next week in Paris.

The PFS is sensitive to radiation in the spectral region of 1.2 - 5
microns and 5 - 50 microns - a region rich with important molecules such
as water and carbon dioxide. Ammonia has a spectral line at 10 microns.

Although Mars Express has been in orbit around Mars since December 2003,
scientists have so far only analysed a fraction of the data the PFS has
produced.

Researchers say this is because they are still coming to terms with the
complexities of the PFS as well as coping with some nagging power
problems on Mars Express.

So far the PFS has observed a depletion of carbon dioxide and an
enrichment of water vapour over some of the large extinct volcanoes on
Mars.

But it is the detection of minor compounds, possible in the sensors
high-resolution mode, that is causing excitement.

The detection of ammonia comes just a few months after methane was found
in the Martian atmosphere. Methane is another gas with a possible
biological origin.

Ammonia is not a stable molecule in the Martian atmosphere. If it was
not replenished in some way, it would only last a few hours before it
vanished.

One possibility the scientists had to rule out was that the ammonia came
from the air bags of the failed Beagle 2 mission. Analysis revealed that
the ammonia's distribution was not consistent with this explanation.

Life on Mars?

The importance of ammonia is that it is a compound of nitrogen and
hydrogen.

Nitrogen is rare in the Martian environment but because no form of
terrestrial life can exist without it the presence of ammonia may
indicate that Martian microbial life is hoarding it.

"There are no known ways for ammonia to be present in the Martian
atmosphere that do not involve life," a US Space Agency (Nasa) scientist
told BBC News Online.

The twin US rovers that landed on the Red Planet in January will be
unable to answer the question of the ammonia's origin as they are
designed for geological work.

But future missions could include sensors to analyse the ammonia to
determine if it has a biological or volcanic origin. Lava deposited on
to the surface, or released underground, could produce the gas.

But, so far, no active volcanic hotspots have been detected on the
planet by the many spacecraft currently in orbit.
Received on Thu 15 Jul 2004 01:33:15 PM PDT