Published March 24, 2016
For mountaineers looking for a fresh challenge, may I suggest Saturn’s largest moon, Titan.
NASA’s Cassini Mission has determined that the moon’s tallest peak is 10,948 feet – about a third as tall as Mount Everest – and almost exactly the height of Black Mountain in Montana. Found within the mountainous ridges called Mirthim Montes, it is one of several towering peaks on Titan that are about 10,000 feet in elevation, according the researchers, who are presenting their findings Thursday at the 47th annual Lunar and Planetary Science Conference at The Woodlands, Texas.
“It's not only the highest point we've found so far on Titan, but we think it's the highest point we're likely to find," Stephen Wall, deputy lead of the Cassini radar team at NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement.
Most of Titan's tallest mountains appear to be close to the equator. The researchers identified other peaks of similar height within the Mithrim Montes, as well as in the rugged region known as Xanadu, and in collections of more isolated peaks called "ridge belts" located near the landing site of ESA's Huygens probe.
The fact that Titan has significant mountains suggests that some active tectonic forces could be affecting the surface. In the future, scientists will be searching for answers as to what could produce such tall peaks on an icy ocean world.
"There is lot of value in examining the topography of Titan in a broad, global sense, since it tells us about forces acting on the surface from below as well as above," Jani Radebaugh, a Cassini radar team associate at Brigham Young University in Provo, Utah, said.
The evolution of Titan's landscape is of interest to scientists partly because of the similarities between the satellite and Earth. Titan is the only moon in the solar system with an atmosphere, and the only other body besides Earth with liquid on its surface. But, Titan's lakes and oceans are made of methane and ethanol, not water.
Using Cassini’s radar instrument, researchers had originally set out to search for active zones within Titan's crust - places where dynamic forces have shaped the landscape, perhaps in the relatively recent past.
"As explorers, we're motivated to find the highest or deepest places, partly because it's exciting. But Titan's extremes also tell us important things about forces affecting its evolution," Radebaugh said.
On Earth, mountains and cliffs such as Himalaya are usually indications that the surface is being pushed upward by geological forces – while such things as erosion and wind wear then down over time.
It’s not that different on Titan, where Cassini found that rain and rivers erode its landscape. But the process probably works much slower on Titan because, at 10 times Earth's distance from the sun, there is less energy to power erosive processes in the moon's atmosphere, Radebaugh said.
The Cassini mission, a cooperative project of NASA, the European Space Agency and the Italian Space Agency, launched in 1997 and arrived in orbit around Saturn in July 2004. The mission — centered on understanding Saturn and its many moons — is expected to continue until 2017 when the spacecraft will be crashed into Saturn's atmosphere.