Rainbows on Titan

Sources: (#1) NIST Chemistry Webbook. Reference temperature: 40^o F for water, -290^o F for methane. Reference pressure 1.5 atm; (#2) AIChE Journal, Volume 42, No. 5, pp. 1425-1433, May 1996; (#3) Les Cowley.

Back to boats: Propellers turning in methane would need to be extra-wide to "grab" enough of the thin fluid for propulsion. They'd also have to be made of special materials resistant to cracking at cryogenic temperatures.

And watch out for those waves! European scientists John Zarnecki and Nadeem Ghafoor have calculated what methane waves on Titan might be like: seven times taller than typical Earth-waves (mainly because of Titan's low gravity) and three times slower, "giving surfers a wild ride," says Ghafoor.

Last but not least, liquid methane is flammable. Titan doesn't catch fire because the atmosphere contains so little oxygen - a key ingredient for combustion. If explorers visit Titan one day they'll have to be careful with their oxygen tanks and resist the urge to douse fires with "water."

Infrared rainbows, towering waves, seas beckoning to sailors. Huygens saw none of these things before it plopped down in the mud. Do they really exist?

"...there is no reason why the other Planets should be without them."