Y: Hey Don, do you remember Saturn’s moon Titan?
D: Of course, Yaël. Who could forget such an interesting moon? Titan is larger than the planet Mercury and has a thick atmosphere of nitrogen. It has lakes and rivers of liquid methane. NASA’s Cassini spacecraft showed that Titan has complex organic molecules like the ones that may have preceded life on Earth. It’s too cold for life as we know it on Titan, but studying its organic chemistry could tell us how life got started on Earth. I sure hope that somebody will send another spacecraft there.
Y: Then I have some good news. In 2019 NASA approved plans for a spacecraft mission to Titan called Dragonfly.
D: Great! I hope they’re sending a roving vehicle, like the ones on Mars!
Y: Actually, they’ll be sending a flying drone with propellers.
D: Oh, Wow! That’s awesome! How come they didn’t do that for Mars?
Y: Titan is very different from Mars. For one thing, the atmosphere is much denser. Mars’s surface air pressure is a puny one hundredth of Earth’s, but Titan’s is almost one and a half times higher than Earth’s. The denser air makes it easier for a propeller to generate lift. Another advantage for flying on Titan is that its gravity is only about a third as strong as Mars’s.
D: I can’t wait! When will it get there?
Y: I’m afraid I have some bad news. Saturn is so far away that Dragonfly will take eight years to get there. It will launch in 2026, but won’t get there until 2034.