Saturn's biggest moon has long been a riddle, wrapped in a mystery — or more accurately, in an ice cube.
For one thing, Titan packs a very unmoon-like atmosphere. In fact, it may be the only moon in our solar system with an atmosphere — nitrogen mostly, with a dash of methane and hydrogen.
And when NASA's Huygens probe briefly tasted Titan's atmosphere back in 2005, it sent some postcards back to the home planet that included wide-ranging plateaus, deserts and oceans.
There's even occasional rainfall.
But all those Earth-like features are tempered by the cold reality that Titan gets about 1% of the sunlight we get here on Earth. That brings the surface temperature down to a bone-cracking minus 179 degrees Celsius (minus 290 Fahrenheit).
Aside from the rivers and rain — which are actually liquid methane — Titan is an icy marble where little stirs.
And yet, it still stirs up a world of intrigue — so much, in fact, that NASA is spending at least $1 billion to pay a visit.
Dragonfly heads to Titan
The space agency's plan is to send a unique spacecraft to not only buzz over Titan but to land and collect samples of water and organic molecules — many of them resembling gases on Earth.
Named for its eight insect-like rotors, Dragonfly will launch in 2026 with an expected ETA of 2034.
But why all the fuss over a distant, flash-frozen moon?
"Titan is unlike any other place in the solar system, and Dragonfly is like no other mission," Thomas Zurbuchen, NASA's associate administrator for science in Washington, D.C., noted in a press release. "The science is compelling. It's the right time to do it."
Indeed, this winged robot that runs on nuclear power will spend most of its nearly three-year mission soaring over Titan's organic dunes and delving the depths of impact craters where liquid water and materials key to life once may have co-existed for millennia.
In other words, Titan may be a time capsule containing all the building blocks of life. It's just been left in the freezer for tens of thousands of years.
"Titan might truly be the cradle for some kind of life — and whether life has emerged or not, Titan's hydrocarbon rivers and lakes, and its hydrocarbon snow, makes it one of the most fantasy-like landscapes in our solar system," Lindy Elkins-Tanton, a planetary scientist at Arizona State University, tells Science magazine.
Looking for signs of life
Dragonfly won't be touring Titan aimlessly. Though there is no map, it will lean heavily on 13 years' worth of data collected by the Cassini mission, essentially a Lonely Planet guide detailing all the lunar landmarks, as well as the best places to land and even what the weather will be like.
This camera-toting tourist will skitter across a moon that's somewhat bigger than the planet Mercury, surveying chemical processes that are similar to those that occur here on Earth.
The ultimate prize? Signs of past life, or even life in the here and now.
"It's remarkable to think of this rotorcraft flying miles and miles across the organic sand dunes of Saturn's largest moon, exploring the processes that shape this extraordinary environment," Zurbuchen adds. "Dragonfly will visit a world filled with a wide variety of organic compounds, which are the building blocks of life and could teach us about the origin of life itself."
And if you can't quite wait until 2034 to see this intrepid robo-explorer in action, check out the video of Dragonfly's simulated landing below: