I’ve been exploring the surface of Titan for several weeks now. During my time here, I have not discovered alien life, but alien life sure has discovered me. Fortunately, the Titanian lake monster I met on Friday is friendly, and he was super excited about meeting someone “from the stars.”
“Wait,” I said, “you know about the stars?”
“Oh yes,” the lake monster said. “I look up at them, twinkling in the night, and also the great orb with the rings around it.”
This really left me flummoxed. I can’t see Saturn at all from the surface of Titan (and I was pretty upset about it too). I certainly can’t see the stars. I can’t even see the Sun through all the tholin haze layered up in Titan’s atmosphere.
However, the tholin haze does allow certain wavelengths of light to pass through, mostly in the infrared part of the spectrum. The haze is almost completely transparent at a wavelength of 2000 nanometers (nm), which is how the infrared camera on the Cassini spacecraft has been able to photograph Titan’s surface.
The human eye can only detect light between roughly 400 and 700 nm. That’s because humans evolved on a planet where the 400 to 700 nm range is dominant, while life on Titan evolved in an environment where infrared light shines the most clearly.
So my new lake monster friend sees in infrared, possibly right around the 2000 nm range, and when he looks up into the sky he can see the Sun and stars and even Saturn, while all I see is gloomy orange haze.