APL to Explore Elements of Life on Saturn’s Moon

Could life exist on another planet? What were the conditions on Earth when life originated here?

On July 5, 2028, Dragonfly — a spacecraft developed by a team from the Johns Hopkins Applied Physics Laboratory (APL) and NASA — will begin a six-year journey before landing on Titan, Saturn’s largest moon, to explore these questions.

In our solar system, only two atmospheres consist mostly of molecular nitrogen, Earth’s and Titan’s. In addition, that moon’s atmosphere is remarkable for its second main gas, methane, and cold temperatures (minus 300 degrees Fahrenheit at the surface) allow for a terrain that includes liquid methane lakes and rivers.

Titan’s unique chemistry also creates an environment rich in organic compounds, including those that are important for life, and analyzing these products provides an unparalleled opportunity to understand what chemistry leads to the formation of life — be it in an extraterrestrial habitat or here on Earth.

“Methane and nitrogen interact with light from the Sun which breaks those two molecules apart, and then the pieces react with each other to build larger and larger molecules,” according to Sarah Hörst, PhD, a Dragonfly team member and a professor in Earth and Planetary Sciences at the Krieger School of Arts and Sciences.

“And these molecules are what we call organic; there’s carbon in them. These are the kinds of molecules we think about being important for the origin of life, the search for life,” Hörst says.

In Hörst’s lab on Homewood Campus, she and her team run simulation experiments to produce and analyze the same organic molecules suspected to be present in Titan’s atmosphere and on its surface. They also test instruments and data analysis techniques that will be used in the Dragonfly mission.

Dragonfly — a car-sized, nuclear-powered drone optimized to work in Titan’s alien environment — will be equipped with a mass spectrometer which will analyze soil samples taken at multiple locations across 50 miles of Titan’s surface.

“We’re taking technology that is becoming very familiar on Earth, and we’re now moving it to another world,” according to Shannon MacKenzie, PhD, the deputy project scientist for the Dragonfly mission at APL.

MacKenzie explains that Dragonfly is being designed to fly autonomously because the distance from Earth to Titan is so great that it takes 90 minutes to send a message there and another 90 minutes to get a message returned.

“A lot of the technology that we are using for Dragonfly isn’t a new creation, but rather a new application, like applying that expertise in autonomous navigation, but to a totally new and foreign environment,” MacKenzie says. “As the deputy project scientist, I work to make sure that the hardware and the systems that we’re building are what we need to actually do the science on the surface of Titan.”

“And I would be shocked if we didn’t find something like amino acids, which are some of the building blocks of life,” she says.

Both Hörst and MacKenzie have been studying Titan from afar for years, building upon the Cassini–Huygens mission, in which NASA, the European Space Agency, and the Italian Space Agency sent a probe that entered Saturn’s orbit in 2004. Additionally, Hörst previously received funding from the Heising-Simons Foundation to study the ocean on Enceladus, one of Saturn’s smaller moons (about one-tenth the size of Titan).

“Studying atmospheres of other planets informs our understanding of our own atmosphere. That’s particularly important as our planet is changing,” Hörst says.

“Sometime in 2034, we’re going to descend through the atmosphere of Titan. We’re going to land on the surface. We’re going to turn the instruments on for the first time on another world, and we’re going to see things that we’ve never seen before. We’re going to learn things that we have been trying to figure out literally for decades,” she adds.