LASER-EYED DEVICE MAY SPEED UP NASA'S SEARCH FOR LIFE ON MARS
A device originally designed to scan for
toxins, pathogens, and other bio-hazards may one day come in handy on a Mars
rover. NASA technologist Branimir Blagojevic from the Goddard Space Flight
Center is testing out a prototype of the Bio-Indicator Lidar Instrument, or
BILI, which would use lasers to scan for the signatures of life on Mars.
Although there are
no current plans to include this instrument on a Mars rover,
Blagojevic says that, with funding, the instrument could be ready for launch in 5 years.
Blagojevic says that, with funding, the instrument could be ready for launch in 5 years.
"We don't believe
we'll find living organisms on Mars, but if life was present, there is a chance
the fingerprints of this past life are still on the surface," says
Blagojevic. "These are the biomarker molecules that this instrument will
be able to detect."
BILI would work by
shining two ultraviolet lasers into Martian dust plumes. The energy of the beam
causes particles in the dust to resonate or fluoresce. Different molecules
create different fluorescence signatures. Those signatures, combined with
information about the size of the particles, allows BILI to classify whether
simple organic molecules, which could provide clues about past life on Mars,
are present.
Although BILI wouldn't
be as precise at identifying exact molecules as other instruments, Blagojevic
says it could be useful as a survey instrument that can cover a lot of ground
quickly. Collecting and analyzing samples is slow work for a rover, whereas
BILI's lasers can almost instantaneously determine the likelihood that an area
contains biologically relevant materials. After sweeping the local area with
the laser beams, the rover could trundle up to the most promising location,
collect a sample, and perform a detailed analysis of what's inside. This way,
Blagojevic says, the instrument could increase the probability of finding
biomolecules.NASA
Some of Mars' slopes seep with a briny water
during the warm season. These wet spots, known as recurring slope linae, may
potentially be capable of supporting life. The steep slopes prevent rovers from
sampling and analyzing these areas, but a laser-based scanner could look for
biosignatures without putting the rover in danger.
With its range of
several hundred meters, BILI could also search for life signs in places where a
rover can't go, such as the recurring slope linae--the areas on Mars that seep with briny water during Mars' warm
season.
When NASA tested BILI
this summer, the instrument was able to discriminate between aerosolized
biomolecules and inorganic molecules that aren't relevant to the search for
life. According to Blagojevich's models, it should work just as well on Mars.
NASA's next Mars rover
launches in 2020, and it's too late to try to get BILI onto the rover, says
Blagojevich. There are no Mars rovers planned beyond 2020, however that's
mostly because NASA scientists still need to sit down and hash out their plans
for the next decade. With the "Journey To Mars" gathering momentum
and public enthusiasm, the red planet will almost certainly star in those
plans. Perhaps BILI will have a role to play, too, whether as an instrument on
a rover or as a handheld scanner for manned missions that try to unravel Mars'
past.
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