Flat spots on Saturn’s moon Titan may be the floors of ancient lake beds
Peculiar flat regions on Saturn’s moon Titan could be the dry floors of ancient lakes and seas. The suggestion, published June 16 in Nature Communications, may solve a 20-year-old mystery. Starting in 2000, astronomers using radio telescopes on Earth have seen particularly bright radio signals coming from Titan’s equator. Those signals, called specular reflections, occur when electromagnetic waves bounce off of a flat surface at the same angle they went in, like light off a mirror. The most natural explanation for the reflections was that Titan had large bodies of liquid in its equatorial tropics. When NASA’s Cassini spacecraft arrived at Saturn in 2004, it did in fact show that Titan is speckled with lakes and seas — although the liquid is ethane and methane, rather than water. “Titan is still currently the only other place in the universe that we know to have liquid on its surface, just like the Earth,” says...