What’s more exciting than flying a helicopter over the deserts of Mars? How about Captain Nemo on Saturn’s big, misty moon Titan – to launch the depths of a methane ocean, dodge hydrocarbon icebergs and an ancient, icy shore of organic goo a billion miles from the sun to explore?
These are the visions that have been dancing through my head recently. Mankind’s eyes are on Mars these days. After half a year in space, a convoy of robots, one after the other, fell on the Red Planet in orbit or straight to the ground, like incoming jets at JFK. Below the cargo is a helicopter that armchair astronauts are looking forward to. flying over the Martian sands.
But my own attention has been drawn to the wider corners of the solar system by the news that Kraken Mare, an ocean of methane on Titan, was recently determined for depth and is probably at least 1,000 feet down. It will recognize as deep as nuclear submarines that they go. The news rekindled my dreams about what I think would be the most romantic of space missions: a journey up, and eventually even down, the oceans of Titan.
“The depth and composition of each of Titan’s seas have been measured, except for Titan’s largest sea, Kraken Mare – which not only has an excellent name but also contains about 80 percent of the moon’s surface fluids,” said Valerio Poggiali. , research fellow, said. at the Cornell Center for Astrophysics and Planetary Science. Dr. Poggiali is the lead author of an article describing the new depth measurements in The Journal of the American Geophysical Union.
NASA recently announced that it will launch a drone named Dragonfly to the Saturnian moon in 2026. Proposals have also circulated for an orbit, a floating probe that could splash into a lake, even a robotic spacecraft. submarine.
“Titan’s submarine is still going strong,” said Dr. Poggiali said in an email, though that is unlikely to happen before Titan’s next summer, around 2047. By then, there will be more ambient light and the submarine could conceivably communicate on a direct line to Earth without ‘ a radio relay.
Titan is in some ways the strangest place in the solar system, and also the world that is most like our own. Like the Earth, it has a thick atmosphere of mostly nitrogen (the only moon with a large atmosphere), and like the Earth it has weather, rain, rivers and seas.
But in this world, when it rains, it rains gasoline. Hydrocarbon material drifts like snow and is formed by nitrogen winds in dunes. Rivers carved gorges through mountains of frozen soot, and layers of ice floated on the ocean of ammonia. The prevailing surface temperature is minus 290 degrees Fahrenheit. A chemical sludge that optimistic astronomers call ‘prebiotic’ is crawling under an oppressive brown sky. Apart from Earth, Titan is the only world in the universe known to contain liquid on its surface – with everything that could imply.
Astrobiologists have been eager to take a closer look at this world since Voyager I swung past it in 1980, proving that its smoky atmosphere was four times as dense as ours. Time, technology and human ingenuity have since revealed that the cloudy world is a natural wonderland.
The northern regions of Titan have a network of lakes and rivers. The largest of them, named Kraken Mare, after a Norwegian monster, is larger than all of North America’s Great Lakes combined.
The Cassini orbit has been teeming with the Saturnian system for 13 years and has mapped out these features in detail.
When Cassini passed approximately 600 kilometers above the northern empire of Titan on 21 August 2014, he used his radar altimeter to measure the depths in Kraken Mare and Moray Sinus, an estuary on the northern shoreline of the sea. Engineers were able to measure the depth of the sea by noting the delay between the radar bouncing off the surface and then bouncing off the seabed.
It turned out that Moray Sinus was about 280 feet deep, but that there was no return from the Kraken bottom; either the lake was very, very deep, or it recorded the radar signals so completely that it never escaped.
“The central part of Kraken Mare must therefore be deeper than 330 feet and probably more than 1000 feet,” said Dr. Poggiali closed.
Another big surprise, according to him, was the composition of Kraken Mare. Scientists expected it to contain relatively more ethane, which is denser than methane than the northernmost sea on Titan, Ligeia Mare.
In the prevailing models of Titan hydrology, dr. Poggiali said, the presence of methane-nitrogen rain is increasing with increasing latitude. This will cause the composition of the more “polar seas” to be more methane rich. “In simple words, ethane behaves a bit like salt in seawater on earth,” he said.
He adds: ‘The composition we deduced for the fluid that fills the Moray Sinus, this large bay in the northern part of Kraken Mare, is quite surprising. We expected it to be definitely more ethane rich. What we found out is that the Kraken is much more similar to the Ligeia Mare, the second largest sea on Titan. This has significant implications for the operation of the hydrological cycle. There may be even more ethane in the southern parts of the Kraken Mare, he added, but the existing data does not extend that far.
It is of more than abstract planetary science. In the imagination of scientists like dr. Poggiali is Titan a laboratory where chemistry could learn over millions of years how to generate energy and store information. ‘These are processes that have also happened on our planet, but they have left no trace! As you can probably see, we need to return to Titan to better understand the mystery of life. he said.
Like an old captain sitting on the dock, dr. Poggiali rattles off the possible voyages of a proposed 20-foot-long NASA submarine. The voyage would begin in the middle of Kraken Mare and ascend to Moray Sinus, where the submarine would measure tides and compositions for three weeks before crossing the shorelines, crossing the bay of Bayta Fretum and driving south through a throaty corridor called Seldon Fretum.
During this exploration, the vessel will map the seabed and periodically sample and, where possible, collect detailed images of the shore. Titan’s gravity on the surface is lower than the earth, so a small submarine can venture deeper without being crushed by pressure, as in a rural ocean of salt water.
In addition, the dr. Poggiali said because methane is transparent to radio waves, the submarine may be able to transmit data directly to Earth while still underwater. Over the course of 90 days, the small submarine could travel 2,000 miles under the sea, at a speed of one foot per second, according to a NASA website describing the proposed submarine.
Meanwhile, I can hardly be blamed for still dreaming of the giant Titanic squid braiding in that freezer-cosmic fish tank with natural gas.
Since the early days of the space program, cosmic visionaries have described space as a ‘new sea,’ as President John F. Kennedy put it in a 1962 speech to Rice University. He never dreamed we could actually sail under it.