[meteorite-list] 'Chemical Laptop' Could Search for Signs of Life Outside Earth

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 17 Nov 2015 12:46:00 -0800 (PST)
Message-ID: <201511172046.tAHKk0iS017119_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4765

'Chemical Laptop' Could Search for Signs of Life Outside Earth
Jet Propulsion Laboratory
November 16, 2015

If you were looking for the signatures of life on another world, you would
want to take something small and portable with you. That's the philosophy
behind the "Chemical Laptop" being developed at NASA's Jet Propulsion
Laboratory in Pasadena, California: a miniaturized laboratory that analyzes
samples for materials associated with life.

"If this instrument were to be sent to space, it would be the most sensitive
device of its kind to leave Earth, and the first to be able to look for
both amino acids and fatty acids," said Jessica Creamer, a NASA postdoctoral
fellow based at JPL.

Like a tricorder from "Star Trek," the Chemical Laptop is a miniaturized
on-the-go laboratory, which researchers hope to send one day to another
planetary body such as Mars or Europa. It is roughly the size of a regular
computing laptop, but much thicker to make room for chemical analysis
components inside. But unlike a tricorder, it has to ingest a sample to
analyze it.

"Our device is a chemical analyzer that can be reprogrammed like a laptop
to perform different functions," said Fernanda Mora, a JPL technologist
who is developing the instrument with JPL's Peter Willis, the project's
principal investigator. "As on a regular laptop, we have different apps
for different analyses like amino acids and fatty acids."

Amino acids are building blocks of proteins, while fatty acids are key
components of cell membranes. Both are essential to life, but can also
be found in non-life sources. The Chemical Laptop may be able to tell
the difference.

What it's looking for

Amino acids come in two types: Left-handed and right-handed. Like the
left and right hands of a person, these amino acids are mirror images
of each other but contain the same components. Some scientists hypothesize
that life on Earth evolved to use just left-handed amino acids because
that standard was adopted early in life's history, sort of like the way
VHS became the standard for video instead of Betamax in the 1980s. It's
possible that life on other worlds might use the right-handed kind.

"If a test found a 50-50 mixture of left-handed and right-handed amino
acids, we could conclude that the sample was probably not of biological
origin," Creamer said. "But if we were to find an excess of either left
or right, that would be the golden ticket. That would be the best evidence
so far that life exists on other planets."

The analysis of amino acids is particularly challenging because the left-
and right-handed versions are equal in size and electric charge. Even
more challenging is developing a method that can look for all the amino
acids in a single analysis.

When the laptop is set to look for fatty acids, scientists are most interested
in the length of the acids' carbon chain. This is an indication of what
organisms are or were present.

How it works

The battery-powered Chemical Laptop needs a liquid sample to analyze,
which is more difficult to obtain on a planetary body such as Mars. The
group collaborated with JPL's Luther Beegle to incorporate an "espresso
machine" technology, in which the sample is put into a tube with liquid
water and heated to above 212 degrees Fahrenheit (100 degrees Celsius).
The water then comes out carrying the organic molecules with it. The Sample
Analysis at Mars (SAM) instrument suite on NASA's Mars Curiosity rover
utilizes a similar principle, but it uses heat without water.

Once the water sample is fed into the Chemical Laptop, the device prepares
the sample by mixing it with a fluorescent dye, which attaches the dye
to the amino acids or fatty acids. The sample then flows into a microchip
inside the device, where the amino acids or fatty acids can be separated
from one another. At the end of the separation channel is a detection
laser. The dye allows researchers see a signal corresponding to the amino
acids or fatty acids when they pass the laser.

Inside a "separation channel" of the microchip, there are already chemical
additives that mix with the sample. Some of these species will only interact
with right-handed amino acids, and some will only interact with the left-handed
variety. These additives will change the relative amount of time the left
and right-handed amino acids are in the separation channel, allowing scientists
to determine the "handedness" of amino acids in the sample.

Testing for future uses

Last year the researchers did a field test at JPL's Mars Yard, where they
placed the Chemical Laptop on a test rover.

"This was the first time we showed the instrument works outside of the
laboratory setting. This is the first step toward demonstrating a totally
portable and automated instrument that can operate in the field," said
Mora.

For this test, the laptop analyzed a sample of "green rust," a mineral
that absorbs organic molecules in its layers and may be significant in
the origin of life, said JPL's Michael Russell, who helped provide the
sample.

"One ultimate goal is to put a detector like this on a spacecraft such
as a Mars rover, so for our first test outside the lab we literally did
that," said Willis.

Since then, Mora has been working to improve the sensitivity of the Chemical
Laptop so it can detect even smaller amounts of amino acids or fatty acids.
Currently, the instrument can detect concentrations as low as parts per
trillion. Mora is currently testing a new laser and detector technology.

Coming up is a test in the Atacama Desert in Chile, with collaboration
from NASA's Ames Research Center, Moffett Field, California, through a
grant from NASA's Planetary Science & Technology Through Analog Research
(PSTAR) program.

"This could also be an especially useful tool for icy-worlds targets such
as Enceladus and Europa. All you would need to do is melt a little bit
of the ice, and you could sample it and analyze it directly," Creamer
said.

The Chemical Laptop technology has applications for Earth, too. It could
be used for environmental monitoring -- analyzing samples directly in
the field, rather than taking them back to a laboratory. Uses for medicine
could include testing whether the contents of drugs are legitimate or
counterfeit.

Creamer recently won an award for her work in this area at JPL's Postdoc
Research Day Poster Session.

NASA's PICASSO program, part of the agency's Science Mission Directorate
in Washington, supported this research. The California Institute of Technology
in Pasadena manages JPL for NASA.


Media Contact

Elizabeth Landau
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
Elizabeth.Landau at jpl.nasa.gov

2015-350
Received on Tue 17 Nov 2015 03:46:00 PM PST