Many
space missions use robots to explore. The rovers Spirit and Opportunity
are still travelling around Mars, taking pictures and digging in the dirt. But
could a robot identify alien life? How would a machine know the difference, for
instance, between a rock and bacteria?
Hoping
to answer this question, a group of scientists led by Derek Pullan of the University of Leicester used robotic explorer instruments to examine rocks here on Earth. To
make their tests as realistic as possible, the researchers collected rock
samples similar to what we'd find on Mars and then studied them with high-tech
equipment. The instruments — which included a camera, microscope, and sampling
device — were very similar to those carried on the lost Beagle
2 probe.
The
idea was to see if the instruments could detect signs of living creatures in
the rocks. Although the tests were carried out in a lab, the scientists made
the conditions as close as possible to those experienced by probes on the martian
surface.
All
of the instruments tested were good at finding signs of life. The interesting
result is that they were much better when used together. This shows how
important it is to not cut corners when building robotic explorers. To get the
whole picture you need a wide variety of instruments working together.
The
Beagle 2-style microscope was found to be particularly good, showing that
low-budget equipment can be as effective as expensive options. The team also
got useful data about how close in proximity to a sample rock particular
instruments should be in order to spot signs of life.
So
why is this research important? Space exploration may be exciting but it's also
dangerous and expensive, which is why robotic probes are sent instead of
people. But the problem with robots is they must be light and compact in order
to fit easily into a rocket. They also must be energy efficient, since their
power is mostly generated from solar panels. This combines to make designing
instruments for them very difficult.
For
example, you might think that a robot exploring
Mars should have the most powerful microscope available. That's probably
not possible as everything must be low-weight, small in size, need little power
and also be very tough. Clearly instrument engineers have a hard job, and the
scientists wanted to see whether the current equipment is up to the task.
More
studies like this are planned for field experiments and sample preparation, as
part of the Planetary Analogue
Field Studies Network. The research is useful not only for instrument
designers, but also for mission engineers and planetary scientists.
The
team plans to do further tests with different equipment, building up a database
that will show which instruments are best in any given situation. It all goes
toward helping make future missions to Mars as effective as possible. Indeed,
if we do find life on another planet, the discovery will be likely made by a
machine and not a human.
The
research is detailed in a February issue of the journal Astrobiology.
advertisement
advertisement
