|
Written by Kamil Shah
|
|
Thursday, 16 December 2004 |
| Introduction
One of the important information which we as human beings want to know
from Mars is whether any life exists on Mars. Although it is very unlikely
to have human-like creatures, primitive bacterial forms may exist. Therefore,
one of the tasks for a Mars rover is to detect these life forms. |
| Viking's failure |
|
Previous rovers such as the 'Viking' had carried a Mars Organic Detector
(MOD) to collect and analyse samples from Mars to determine whether any
life has or had been present on the Martian ground. However, no positive
result was found. This may be due to the fact that the sensitivity of the
MOD onboard Viking was very low (part per billion range) . As a single bacteria
only measured around 10-16 grams and only 1/3 of that is actually amino
acid. Therefore, in 1 gram of soil, the instrument would not be able to
measure anything even though there might be 1 million bacteria cells in
it. |
MOD in Berkeley
In order to improve the sensitivity of the instrument, University of
California, Berkeley, is trying to develop a new MOD which can be used
in the 2009 rover to Mars. From the technology it advanced from the human
genome project, the new MOD aims to measures the amino acid composition
and by analysing the ratio of optical isomers present, hence determines
whether any life is present. As we all know, one major building block
of life is protein and a chemical block for a protein is an amino acid.
There are two optical isomers of amino acids. On earth, animated beings
only contain one type of amino acid isomer. Therefore, when analysing
the chirality of the amino acids we can find a sharp peak at d-isomer
amino acids. Likewise when we employ this new technology onto Mars Rovers,
we can find out whether life actually exist in Mars by observing either
a peak at l-type or d-type isomers. Furthermore, this device which is
being developed in Berkeley is about 1000 times more sensitive than the
Viking mission. Therefore, it would be more likely to observe life on
Mars if there is any. The results would take around 30 minutes to generate
along with the transmission time of the data, the information can reach
back to Earth in a relatively short period of time and multiple tests
can be performed to confirm the presence or absence of life on Mars.
|
How does the MOD work?
For the Viking, the MOD uses sublimation to obtain samples of amino
acids. A sample is heated up and turns into gaseous form. The gas then
sublimes to form amino acid solids on the edge of the 'cold finger' which
contains liquid nitrogen. The amino acid solids are then analysed to find
out the type of amino acid it contains.
|
What is in it for the future?
It is unlikely that human beings would stop reaching new realms of
space in the vast universe. As we would like to confirm that we are
or are not the only animated beings in the universe and that there might
be some form of 'parallel' world out there, it isn't likely for us to
give up testing for life on another planet. Where human beings cannot
reach the surface, rovers will have the responsibility of perform such
complex tasks. In the future, the MODs or planetary organic detectors
(POD) on board will become more and more accurate and maybe we would
be able to find new forms of life in our universe.
How does this fit into our system?
This would be a specific task and therefore a POD would be carried
by a small rover which is in charge of performing the specific task
of life detection. Samples would be collected from the surface of the
planet, either by means of drilling or digging. This would then be analysed
by the POD, the data would then be sent to the mother ship whether it
would have an autonomous job of analysing the data. If the data shows
some interesting results, it would send the data back to Earth using
the backbone network which is described in communications.
|
[
NEXT ]
|
|
Last Updated ( Saturday, 09 July 2005 )
|
