Like water on Earth, the methane has slowly etched canyons into the landscape and filled them with lakes. Lakes that, perhaps someday, human beings might visit for a little R&R, hundreds of millions of miles away.
It’s unlikely, but summer, arguably the best season for daydreaming, is upon us, so I reached out to a few scientists who study Titan to gauge the moon’s qualifications for a cosmic getaway. Set aside the long and dangerous journey, which would require astronomical leaps in technology if you planned to leave tomorrow. What might it be like to stand on the shores of a Titanian lake and look out across the expanse?
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Well, you wouldn’t be able to see much, actually. Our dinky human eyes weren’t made for Titan, which is covered in thick haze, tinted the color of Dijon mustard because of chemical interactions between sunlight and compounds in the moon’s atmosphere. Unlike on Earth, sunlight strains to break through to the surface.
“Our vision is adapted to the situation on Earth—a lot of visible light,” says Daniel Cordier, a scientist at the University of Reims in France. “On Titan, only a tiny fraction of visible light entering the atmosphere reaches the ground.”
To get a better look, vacationers would need high-tech sunglasses designed to see in other forms of light, like infrared. You wouldn’t need to pack sunscreen; the sun appears 10 times smaller on Titan than it does here on Earth.
You wouldn’t need a spacesuit either, which sounds inconceivable, considering that every person who has ever left the comfort of Earth’s atmosphere has had to wear protective material to prevent a swift death. But air on Titan is dense enough to allow people to walk around without pressurized spacesuits, free from bulky, constricting garments and the danger of their bodily fluids boiling. By this measure, Titan isn’t as inhospitable as other worlds in the solar system, like our own moon or Mars.
No stepping outside without an oxygen mask, though: Titan’s atmosphere is made of about 95 percent nitrogen. You’d also need the right clothes to contend with the temperature. This moon’s fleece of an atmosphere keeps the surface temperature about the same day after day, changing only by a degree or two. This might sound pleasant, but that temperature is about –292 degrees Fahrenheit (–180 degrees Celsius). Visitors would need garments layered with insulation or designed to generate heat for its wearers.
Let’s say you’ve chosen a Titan lake called Ligeia Mare as your holiday spot. Ligeia Mare is about the combined size of two Great Lakes, Huron and Michigan, but looks nothing like them. The surface is smooth, nearly textureless. There are no big waves, no whitecaps at their shifting peaks. When Cyril Grima, a scientist at the University of Texas, imagines himself there, he looks down at his feet and spots a block of ice the size of his fist. He thinks about throwing it out into the lake; at these temperatures, water on Titan exists only as ice and litters the surface like rocks. But he wouldn’t want to disturb the eerie tranquility of the alien lake. “You don’t want to break this quiet liquid body, as peaceful as pristine snow before being lacerated by footprints,” Grima says.