All sky watchers know that there’s only one Lord of the Rings up there: the magnificent planet Saturn. But very few people realise that many of the mountains on its giant moon Titan have recently been named for fictional peaks in Tolkien’s books. Detailed mapping of Titan has been possible in the past few years through the joint NASA-European Space Agency space probe mission called Cassini.
In addition to a Mount Doom (a volcano according to the novels), there is now on Titan a Mount Erebor, the Lonely Mountain, where Bilbo and company travel to fight the fearsome dragon Smaug in The Hobbit.
Despite their origination in fiction, the names are still quite formal, the astronomers using Latin versions for the mountains. Avid Tolkien buffs will recognise Misty Montes as the Misty Mountains, which house the city of Khazad-dûm and also the Mines of Moria, where the dwarves dug too greedily and too deep, releasing the demon Balrog which slays Gandalf.
The mountains on frigid Titan, so far from the Sun, are not like terrestrial peaks. They are made of ice, water ice. The temperature way out on Titan is around –180°C, and not even the South Pole gets that cold on Earth. Titan, though, has some of the most Earth-like processes of any other body in our solar system. If it wasn't in orbit around Saturn it might be classified as a planet itself, being fully 40 percent the diameter of our own home, the third rock from the Sun.
Titan is the only moon in the solar system with a permanent atmosphere, unlike our airless companion. It also has lakes and rivers, but not of water, which is all frozen solid out there: what we see flowing on Titan is liquid methane and nitrogen! Titan is truly an unusual and spectacular world.
Titan’s mountains, ranging up to 1.5 km (or almost a mile) high, have continually formed and reformed as that moon slowly cools, gradually releasing heat from the time of its formation over four billion years ago. Its outermost ice crust has thickened and folded, as it shrivels up like a raisin. Some of these ‘creases’ have resulted in vast chains of peaks: Echoriath Montes, the Latin name derived from Tolkien’s Echoriath (or Encircling) Mountains, is 930 km long. Erebor Mons is 50 km in diameter.
Deposits of some sort of bright, white material – thought to be methane ‘snow’ or exposures of some other organic (carbon-bearing) materials – lie at the top of the mountain ridges, making them appear somewhat like the Southern Alps.
Titan is proving to be an amazing world which may hold the key to how life started, or may even be a host for extraterrestrial life: only microbes though, we’re pretty sure there are no ‘little green men’ on Titan!
Education Coordinator, KiwiSpace Foundation
Publicity Officer, Royal Astronomical Society of New Zealand
With thanks to Titan Saturn's Moon on Facebook and Duncan Steel
http://www.carterobservatory.org/ (More details about Titan you can see in the 'Wildest Weather of the Solar System' planetarium show)