nationalgeographic | Titan's allure is manyfold: It has a thick atmosphere—the only moon in the solar system
to have one—stable liquid on its surface, and a landscape of lakes,
seas, and dunes. So it's no surprise that astronomers are keeping an eye
on Saturn's largest satellite.
Scientists
now say the Huygens probe that landed on Titan in 2005 did so with a
bounce, slide, and wobble, yielding new clues about its Earthlike
terrain.
Meanwhile, a Spanish team has proposed sending a boatlike
probe that could paddle or propel itself across Ligeia Mare, a vast,
liquid hydrocarbon lake near Titan's north pole. The inspiration for the
probe's design includes Mississippi River paddleboats and an amphibious
Soviet vehicle with screwlike propellers.
"We thought, why not be
capable of moving after landing so you can study the landing site,
cruise to the shore, and explore the shore?" said Igone Urdampilleta, an
aerospace engineer with SENER, a private Spanish engineering firm.
SENER is developing the design—presented at the European Planetary Science Congress in Madrid in September—with Madrid's Centro de Astrobiología.
The
still conceptual probe, called the Titan Lake In-situ Sampling
Propelled Explorer (TALISE), would take both liquid and soil samples to
learn more about Titan's organically rich environment.
Imagine
a world shrouded in an orange-brownish fog where it rains methane, the
temperature is minus 290 degrees Fahrenheit (nearly 180 below zero
Celsius), and a year lasts 29.5 Earth years.
"If you were to
bottle some of Titan's atmosphere, then opened the bottle on Earth, it
might smell a bit like an oil refinery," said Titan expert Ralph Lorenz
of the University of Arizona. "Titan is so much colder, [so] what might
be sticky goop on Earth is literally rock hard on Titan."
By the
same token, methane and ethane—components of natural gas on Earth and
thought to be prevalent on Titan—would exist in liquid form there.
According to Lorenz, scientists are "99-plus percent" certain that
Ligeia Mare consists mostly of liquid ethane and methane, with the lake
stretching several hundred meters across and at least 33 feet (10
meters) deep.
