A new NASA mission to Saturn’s giant moon, Titan, is due to launch in 2027. When it arrives in the mid-2030s, it will begin a journey of discovery that could bring about a new understanding of the development of life in the universe. This mission, called Dragonfly, will carry an instrument called the Dragonfly Mass Spectrometer (DraMS), designed to help scientists hone in on the chemistry at work on Titan. It may also shed light on the kinds of chemical steps that occurred on Earth that ultimately led to the formation of life, called prebiotic chemistry.
This
illustration shows NASA’s Dragonfly rotorcraft-lander approaching a site on
Saturn’s exotic moon, Titan. Taking advantage of Titan’s dense atmosphere and
low gravity, Dragonfly will explore dozens of locations across the icy world,
sampling and measuring the compositions of Titan's organic surface materials to
characterize the habitability of Titan’s environment and investigate the
progression of prebiotic chemistry. Credits: NASA/JHU-APL
Titan's abundant complex carbon-rich
chemistry, interior ocean, and past presence of liquid water on the surface
make it an ideal destination to study prebiotic chemical processes and the
potential habitability of an extraterrestrial environment.
DraMS will allow scientists back on Earth
to remotely study the chemical makeup of the Titanian surface. “We want to know
if the type of chemistry that could be important for early pre-biochemical
systems on Earth is taking place on Titan,” explains Dr. Melissa Trainer
of NASA’s Goddard Space Flight Center, Greenbelt, Maryland.
The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Credits: NASA/JPL-Caltech/Space Science Institute
Trainer is a
planetary scientist and astrobiologist who specializes in Titan and is one of the
Dragonfly mission’s deputy principal investigators. She is also lead on the
DraMS instrument, which will scan through measurements of samples from Titan’s
surface material for evidence of prebiotic chemistry.
To accomplish this, the Dragonfly robotic
rotorcraft will capitalize on Titan’s low gravity and dense atmosphere to fly
between different points of interest on Titan’s surface, spread as far as
several miles apart. This allows Dragonfly to relocate its entire suite of
instruments to a new site when the previous one has been fully explored, and
provides access to samples in environments with a variety of geologic
histories.
At each site, samples less than a gram in
size will be drilled out of the surface by the Drill for Acquisition of Complex
Organics (DrACO) and brought inside the lander’s main body, to a place called
the “attic” that houses the DraMS instrument. There, they will be irradiated by
an onboard laser or vaporized in an oven to be measured by DraMS. A mass
spectrometer is an instrument that analyzes the various chemical components of
a sample by separating these components down into their base molecules and
passing them through sensors for identification.
“DraMS is designed to look at the organic
molecules that may be present on Titan, at their composition and distribution
in different surface environments,” says Trainer. Organic molecules contain
carbon and are used by all known forms of life. They are of interest in
understanding the formation of life because they can be created by living and
non-living processes.
Mass spectrometers determine what’s in a sample by
ionizing the material (that is, bombarding it with energy so that the atoms
therein become positively or negatively charged) and examining the chemical
composition of the various compounds. This involves determining the
relationship between the weight of the molecule and its charge, which serves as
a signature for the compound.
DraMS was developed in part by the same
team at Goddard which developed the Sample Analysis at
Mars (SAM)
instrument suite aboard the Curiosity rover. DraMS is designed to survey
samples of Titanian surface material in situ, using
techniques tested on Mars with the SAM suite.
Trainer emphasized the benefits of this
heritage. Dragonfly’s scientists did not want to “reinvent the wheel” when it
came to searching for organic compounds on Titan, and instead built on
established methods which have been applied on Mars and elsewhere. “This design
has given us an instrument that’s very flexible, that can adapt to the
different types of surface samples,” says Trainer.
DraMS and other science instruments on
Dragonfly are being designed and built under the direction of the Johns Hopkins
Applied Physics Laboratory in Laurel, Maryland, which manages the mission for
NASA and is designing and building the rotorcraft-lander. The team includes key
partners at Goddard, the French space agency (CNES, Paris, France), which is
providing the Gas Chromatograph Module for DraMS that will provide an
additional separation after leaving the oven, Lockheed Martin Space, Littleton,
Colorado, NASA Ames Research Center at Moffett Federal Airfield in California's
Silicon Valley, NASA Langley Research Center, Hampton, Virginia, NASA Jet
Propulsion Laboratory, Pasadena, California, Penn State University, State
College, Pennsylvania, Malin Space Science Systems, San Diego, California,
Honeybee Robotics, Brooklyn, New York, the German Aerospace Center (DLR),
Cologne, Germany, and the Japan Aerospace Exploration Agency (JAXA), Tokyo,
Japan.
Dragonfly is the fourth mission in NASA’s New Frontiers program. New Frontiers is managed by NASA's
Marshall Space Flight Center in Huntsville, Alabama, for the agency's Science
Mission Directorate Washington.
By: Nick Oakes
NASA Goddard Space Flight Center, Greenbelt, Maryland
Source: NASA Instrument Bound for Titan Could Reveal Chemistry Leading to Life
No comments:
Post a Comment