Space Boat A Nautical Mission To An Alien Sea

"TiME This capsule designed to explore Titan's seas is one of three projects being considered to receive NASA funding next year. Graham Murdoch"

In 2006, while flying by Saturn's moon Titan, the radar on NASA's Cassini orbiter discovered seas of liquid ethane and methane on the moon's -300oF surface, the only bodies of liquid we know of that exist anywhere but on Earth. Some of the oily seas appeared on Cassini's radar to be larger than Lake Superior, but visibility was poor because Titan's atmosphere is thick and hazy.

Now NASA is considering sending a probe called the Titan Mare Explorer (TiME) to splash down on one of Titan's seas for a closer look. The mission would be humankind's first extraterrestrial nautical expedition.

In May, the TiME project received a 3-million development contract from NASA. If the space agency green-lights the mission, the capsule will lift off in 2016. By 2023, TiME will be about 800 million miles away in Titan's north-polar region, home to its biggest lakes and seas. The capsule will take photographs, collect meteorological data, measure depth, and analyze samples. TiME will have no means of propulsion once it is on Titan, so it will float, carried by breezes across the sea's surface. Then, by the mid-2020s, it will enter a decade-long winter of darkness as the moon's orbit takes it to the dark side of Saturn, away from the sun and communication. It won't have a line of sight to Earth to beam back more data until 2035.

Methane clouds drift in Titan's smoggy orange skies, sometimes releasing hydrocarbon raindrops, which replenish the seas and sculpt the landscape the way water does on Earth. But Titan's seas probably don't contain life. "Life as we know it requires liquid water, and Titan's surface is far too cold for this," says Ralph Lorenz, a physicist at Johns Hopkins University who is working on TiME. "Its seas can tell us about how molecules organize and evolve, and how life may arise more generally." TiME's principal investigator, planetary geologist Ellen Stofan, wonders about the waves: "Are there hazes, sea spray? Is the liquid clear or cloudy? Is there scum floating on the surface? With Titan's seas, there are endless questions."

SPLASH LANDING ON TITAN'S SEA

DROP IN

After a seven-year journey, including gravitational slingshots around Earth and Jupiter, the Titan Mare Explorer (TiME) passes through Titan's thick nitrogen and methane atmosphere, protected by its heat shield.

DRIFT DOWN

At an altitude of about 100 miles, TiME deploys its parachute. During the remainder of its roughly two-hour descent, the probe's camera snaps pictures while a thermometer and barometer record meteorological data.

FLOAT AROUND

After landing in the ethane and methane sea Ligeia Mare, TiME's mass spectrometer collects a sample to analyze its chemical composition, while its sonar measures the sea's depth. Without its own means of propulsion, the capsule will bob along in the gentle wind and currents. It might even experience alien rains or wash up on an extraterrestrial beach.

COSMIC CONTENDERS

Next year, NASA will give full funding to one of three missions: a Mars probe to study how the planet formed, a "comet hopper" that will repeatedly land on a near-Earth comet, or a capsule to float on a sea on Titan, one of Saturn's 53 known moons. The Jet Propulsion Laboratory's Geophysical Monitoring Station would study Mars's interior structure and composition to better understand its geological history. The Comet Hopper, conceived at NASA's Goddard Space Flight Center, would land several times on a comet, studying how the icy body evolves as it warms up while approaching the sun.

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A Liquid Lake On Saturns Moon

Ligeia Mare, a lake on Saturn's moon Titan, in a false-color image from NASA's Cassini spacecraft. Image v8a NASA/JPL-Caltech/ASI/Cornell

Ligeia Mare is one of the many bodies of liquid in and around the north polar region of Saturn's largest moon, Titan. The lake is liquid, but the liquid isn't water, which would freeze at Saturn's distance from the sun. The temperature at Titan's surface is about -289 degrees Fahrenheit (-178 degrees Celsius). Instead, the liquid in this Titan lake is mainly methane and ethane as well as other liquid hydrocarbons.

The lake's name comes from one of the beautiful and dangerous sirens in Greek mythology, Ligeia. The sirens were said to sing so sweetly that passing sailors would shipwreck on the rocky coast of their island.

Ligeia Mare is second in size only to another lake, Kraken Mare, on Titan. It measures approximately 260 miles by 217 miles (420 km by 350 km) and has a shoreline that's longer than 1,240 miles (2,000 km)! A day at the beach, anyone?

This image of Saturn's largest moon Titan is from Cassini - taken in 2005. It shows approximately what Titan would look like to the human eye: a hazy orange globe surrounded by a tenuous, bluish haze. Titan has a very thick atmosphere that the eye can't penetrate. The lakes on Titan are detected via Cassini's radar. Image via NASA

The images on this page are just two of many amazing ones from NASA's Cassini mission to Saturn. The spacecraft has been orbiting in and among Saturn's rings and moons since 2004. Read more about the Cassini mission here.

Be sure to check out more EarthSky Today's Images

Source: ovni-news.blogspot.com

Forecast For Titan Wild Weather Could Be Ahead

Saturn's moon Titan might be in for some wild weather as it heads into its spring and summer, if two new models are correct. Scientists think that as the seasons change in Titan's northern hemisphere, waves could ripple across the moon's hydrocarbon seas, and hurricanes could begin to swirl over these areas, too. The model predicting waves tries to explain data from the moon obtained so far by NASA's Cassini spacecraft. Both models help mission team members plan when and where to look for unusual atmospheric disturbances as Titan summer approaches.

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Ligeia Mare, shown in here in data obtained by NASA's Cassini spacecraft, is the second largest known body of liquid on Saturn's moon Titan. It is filled with liquid hydrocarbons, such as ethane and methane, and is one of the many seas and lakes that bejewel Titan's north polar region. Cassini has yet to observe waves on Ligeia Mare and will look again during its next encounter on May 23, 2013 [Credit: NASA/JPL-Caltech/ASI/Cornell]"

"If you think being a weather forecaster on Earth is difficult, it can be even more challenging at Titan," said Scott Edgington, Cassini's deputy project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We know there are weather processes similar to Earth's at work on this strange world, but differences arise due to the presence of unfamiliar liquids like methane. We can't wait for Cassini to tell us whether our forecasts are right as it continues its tour through Titan spring into the start of northern summer."

Titan's north polar region, which is bejeweled with sprawling hydrocarbon seas and lakes, was dark when Cassini first arrived at the Saturn system in 2004. But sunlight has been creeping up Titan's northern hemisphere since August 2009, when the sun's light crossed the equatorial plane at equinox. Titan's seasons take about seven Earth years to change. By 2017, the end of Cassini's mission, Titan will be approaching northern solstice, the height of summer.

Given the wind-sculpted dunes Cassini has seen on Titan, scientists were baffled about why they hadn't yet seen wind-driven waves on the lakes and seas. A team led by Alex Hayes, a member of Cassini's radar team who is based at Cornell University, Ithaca, N.Y., set out to look for how much wind would be required to generate waves. Their new model, just published in the journal Icarus, improves upon previous ones by simultaneously accounting for Titan's gravity; the viscosity and surface tension of the hydrocarbon liquid in the lakes; and the air-to-liquid density ratio.

"We now know that the wind speeds predicted during the times Cassini has observed Titan have been below the threshold necessary to generate waves," Hayes said. "What is exciting, however, is that the wind speeds predicted during northern spring and summer approach those necessary to generate wind waves in liquid ethane and/or methane. It may soon be possible to catch a wave in one of the solar system's most exotic locations."

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This image shows the first flash of sunlight reflected off a hydrocarbon lake on Saturn's moon Titan. The glint off a mirror-like surface is known as a specular reflection. This kind of glint was detected by the visual and infrared mapping spectrometer (VIMS) on NASA's Cassini spacecraft on July 8, 2009. It confirmed the presence of liquid in the moon's northern hemisphere, where lakes are more numerous and larger than those in the southern hemisphere. Scientists using VIMS had confirmed the presence of liquid in Ontario Lacus, the largest lake in the southern hemisphere, in 2008 [Credit: NASA/JPL/University of Arizona/DLR]"

The new model found that winds of 1 to 2 mph (2 to 3 kilometers per hour) are needed to generate waves on Titan lakes, a speed that has not yet been reached during Titan's currently calm period. But as Titan's northern hemisphere approaches spring and summer, other models predict the winds may increase to 2 mph (3 kilometers per hour) or faster. Depending on the composition of the lakes, winds of that speed could be enough to produce waves 0.5 foot (0.15 meter) high.

The other model about hurricanes, recently published in Icarus, predicts that the warming of the northern hemisphere could also bring hurricanes, also known as tropical cyclones. Tropical cyclones on Earth gain their energy from the build-up of heat from seawater evaporation and miniature versions have been seen over big lakes such as Lake Huron. The new modeling work, led by Tetsuya Tokano of the University of Cologne, Germany, shows that the same processes could be at work on Titan as well, except that it is methane rather than water that evaporates from the seas. The most likely season for these hurricanes would be Titan's northern summer solstice, when the sea surface gets warmer and the flow of the air near the surface becomes more turbulent. The humid air would swirl in a counterclockwise direction over the surface of one of the northern seas and increase the surface wind over the seas to possibly 45 mph (about 70 kilometers per hour).

"For these hurricanes to develop at Titan, there needs to be the right mix of hydrocarbons in these seas, and we still don't know their exact composition," Tokano said. "If we see hurricanes, that would be one good indicator that there is enough methane in these lakes to support this kind of activity. So far, scientists haven't yet been able to detect methane directly."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. The mission is managed by JPL for NASA's Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology in Pasadena, Calif.

For more information about Cassini and its mission, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

"Source: NASA/Jet Propulsion Laboratory [May 22, 2013]"