Titan will be the target of NASA's next space mission, one intended to launch in just seven years time. Unfortunately, we'll then have to wait another eight years for its findings, but when they come they should be spectacular, with a flying vehicle capable of hopping more than 100 miles across the giant moon to sample the most interesting-looking sites.
The mission, known as Dragonfly, has been under consideration for many years, but with so many places we want to visit in the Solar System, it has faced stiff competition for funding. Eighteen months ago NASA announced the choice for the next mission had been narrowed from 12 to two: Dragonfly and a return to Comet 67P/Churyumov-Gerasimenko, this time bringing samples back to Earth.
The arguments for Titan are strong. Although very cold, -179º C (-290º F) on average, it is the closest analogy we have for early Earth, including seas and lakes on its surface. The combination of an atmosphere four times as dense as our own and gravity one-seventh as strong makes flight extremely practical, so Dragonfly will be able to cover more territory on Titan than all the Mars rovers combined.
On the other hand, those too impatient to wait for 2034 have pointed to the merits of closer locations. Moreover, while there are still some who hold out hope for the possibility of life on Titan, it has dropped behind its fellow moons Europa and Enceladus in most astrobiologists' assessment.
After weighing all the options NASA announced in favor of Titan, with a mission intended to last at least 2.7 years after arrival.
“With the Dragonfly mission, NASA will once again do what no one else can do,” NASA Administrator Jim Bridenstine said in a statement. “Visiting this mysterious ocean world could revolutionize what we know about life in the universe. This cutting-edge mission would have been unthinkable even just a few years ago, but we’re now ready for Dragonfly’s amazing flight.”
Titan is an exceptionally diverse place, and NASA plans to send Dragonfly first to the Shangri-La dunes near its equator. After using its eight drone-like rotors to hop around taking samples it will reach the Selk impact crater, which Cassini provided evidence once held liquid water and organic molecules, making it the Moon's best prospect for finding remnants of life. Eventually, we might get a look at the recently proposed hydrocarbon crystals.
Dragonfly will inform us of the composition of Titan's underground liquid reservoirs, as well as its surface lakes. However, the idea of using a submarine to sail through the Kraken Mare, Titan's largest hydrocarbon sea, will have to wait for another decade or two, and probably an increased planetary science budget.
NASA's artists have provided this vision of how they imagine the craft and its targets will look.
