When the Huygens probe came down from Cassini spacecraft in 2005 and gave humans a close-up of Titan’s dense atmosphere, scientists began dreaming of a future mission that would further explore Saturn’s largest moon. Thus, the seeds of the Dragonfly mission were sown. This groundbreaking mission can provide clues to the habitability of the Titans as well as to the chemical processes that lay the foundation for the emergence of life.
What is Dragonfly?
That Jeweler mission is scheduled to last at least 32 months and can be extended if the vehicle and instruments on board remain functional. To perform its scientific tasks, Dragonfly will travel around the moon using an “8-bladed rotorcraft” or a drone. Exploring Titan via drone presents many unique challenges. Because Titan’s atmosphere is so dense (1.5 times denser than Earth’s), it may actually be easier for a drone to take flight on the moon. However, because of Titan’s distance from Earth, communication takes too long for NASA scientists to forward real-time commands to the vehicle. Thus, the Dragonfly must operate autonomously, which includes checking favorable weather conditions before being lifted off.
Dragonfly is designed for Titan’s dense atmosphere and surface conditions and contains a number of instruments for measuring chemical, meteorological and geological processes: a mass spectrometer for molecular identification, a neutron and gamma ray spectrometer for surface analysis, a seismometer for measuring tectonic motion, flight sensors and radars. a number of cameras. Dragonfly will collect and test surface material on board and can return to locations where sample analysis proves to be tantalizing or inconceivable.
Dr. Rosaly Lopes, a senior researcher at NASA’s Jet Propulsion Laboratory currently studying geological data from the Cassini mission, said that when the idea of flying a drone on Titan was first proposed, the concept “had not yet been proven anywhere.” NASA’s Ingenuity helicopter is scheduled to explore Mars in the spring of 2021 as part of March 2020 mission and will represent the first motor flight in another world if successful. Dragonfly could be the other.
Titan is the solar system’s second largest moon and is larger than the planet Mercury. About 886 million miles away, it is about ten times farther away from the sun than the Earth is. A year on Titan corresponds to approx. 29 years on earth. Temperatures can drop to almost -300 ° Fahrenheit on the surface. These properties may make Titan seem like a strange place to look for clues about the origin of life, but according to Dr. Elizabeth Turtle, principal investigator of Dragonfly Mission, has Titan chemical similarities with early Earth.
“There is organic matter, water at impact craters, cryovolcanoes and sunlight as the energy that drives it all,” says Turtle. “All the ingredients of life as we know it exist and interact on the surface.”
Titan is the only celestial body other than Earth known to support liquid bodies such as rivers and lakes. But unlike on Earth, these functions on Titan consist of hydrocarbons, such as liquid methane and ethane. Dragonfly provides data for assessing precipitation cycles, evaporation of moisture and cloud formation on the moon.
Understanding the relationship between the moon’s atmosphere and its surface will also help geologists who, according to Lopes, “[Titan] has the greatest geological features that the Earth does … including dunes, lakes and seas, erosion by rivers, mountains and volcanoes. ”
What do researchers hope to learn?
Dragonfly’s main goal is to gain a better understanding of Titan’s chemical progression. Early Earth had a chemical environment similar to Titan, and on Earth “chemistry became biology,” says Turtle. But the chemical past of Titan is unknown, and it is unclear whether it has followed, follows, or will follow a path similar to that of Earth; researchers only know that similar ingredients existed.
“We want to understand these early chemical stages and how far chemistry has evolved on Titan,” Turtle says.
Much of that chemistry occurs in its atmosphere, which is 95% nitrogen (N2) and 5% methane (CH4). The methane molecules split as they are accelerated by Saturn’s magnetism and the Sun’s ultraviolet light, allowing hydrogen to escape and other molecules to be recombined into hydrocarbons. Given the current amount of methane in Titan’s atmosphere, Turtle estimates that “methane life is in the order of 10 million years,” meaning that Dragonfly will search for information on the origin of methane and Titan’s atmospheric life. Scientists are not entirely sure how Titan’s atmosphere is supplied with methane again – it could be stored in reservoirs in the crust of the moon, due to cryo-volcanic eruptions or coming out of sulfur holes under water. Dragonfly may have the opportunity to witness this process first hand.
The Dragonfly mission will return an abundance of data regarding Titan, data that will shape the scientific path for many early career astrobiologists in the years to come. Dr. Natalie Grefenstette, postdoctoral fellow at the Santa Fe Institute, who holds a Ph.D. in prebiotic chemistry, says that the scientific community is “excited to see what the environment is [on Titan] produces naturally. ”
The mission’s focus on lunar chemistry will provide insight into whether Titan could support life now or in the past. Instead of limiting Dragonfly’s analysis of samples to the molecules that scientists have identified as fundamental to terrestrial life, Grefenstette hopes the mission will uncover unexpected “evidence of proto-life or life-like systems.” Such discoveries can help astrobiologists understand how life forms work in other worlds and whether the particular expression of life on Earth is unique.
“To be able to see what happened in [Titan’s] environment will give us perspective on what happened in other environments as well as on habitability in general, ”says Turtle.