Why is titan habitable

We ask why they would go to that trouble. We can live underground on Earth. Beyond Mars, the next potential home is among the moons of Jupiter and Saturn. There are dozens of choices among them, but the winner is obvious. Titan is the most Earthlike body other than our original home. Titan is the only other body in the solar system with liquid on the surface, with its lakes of methane and ethane that look startlingly like water bodies on Earth. It rains methane on Titan, occasionally filling swamps.

On the surface, vast quantities of hydrocarbons in solid and liquid form lie ready to be used for energy. Although the atmosphere lacks oxygen, water ice just below the surface could be used to provide oxygen for breathing and to combust hydrocarbons as fuel.

Housing could be made of plastic produced from the unlimited resources harvested on the surface, and could consist of domes inflated by warm oxygen and nitrogen. The ease of construction would allow huge indoor spaces. The recreational opportunities on Titan are unique. For example, you could fly. If the wings fall off, no worry, landing will be easy. Terminal velocity on Titan is a tenth that found on the Earth. How will we get there?

Exploration: In , the Pioneer 11 spacecraft reached Saturn and calculated the temperature on Titan, concluding at that time that Titan was too cold to support life. The Voyager 1 spacecraft honed in on Titan in its mission. Due to the thick cloud cover, Voyager could not capture Titan's surface on film, though other data was collected. The Cassini mission, with its spacecraft now en route, is hoped to yield the first detailed look at Titan's surface.

The probe will collect atmospheric data as it descends to the ground. For life to be able to exist in or near Titan's ocean, there must be a source of chemical energy to metabolize. Building on the work done in Objectives 1 and 2 relating to what organics reach the ocean and what the environment of the ocean is like, the team will then be able to construct theoretical models of how much energy is available in the ocean, as well as possible metabolisms that could exist in those conditions, to gauge the likelihood that life could survive there.

Assuming the ocean is habitable, with sources of chemical energy and a healthy supply of organics, the high pressure and low temperature environment may constrain the variety of lifeforms that could exist there.

However, one terrestrial organism that the team are considering as a suitable example is Pelobacter acetylenicus , which can survive on acetylene as its only source of metabolic energy and carbon.

Laboratory experiments will be conducted, placing microbes such as Pelobacter acetylenicus in simulated environments described by the aforementioned theoretical modeling to see if the microbes can thrive in them, to learn how they adapt in order to survive, and what new types of biomolecules might result from these adaptations.

These biomolecules may then leave behind biosignatures—molecular traces of life. However, while the possible existence of life in the ocean of Titan is all well and good, we also need to be able to detect that life via biosignatures.

Understanding what biomarkers life could leave is therefore the second part of Objective 3, and a database of potential biosignatures will be produced, including isotopes of carbon, nitrogen and oxygen, as well as biological structures such as the lipids in cell membranes.

Of course, if the biosignatures remain in the ocean, they will be impossible to detect from orbit or on the surface. Therefore, the final objective is to seek means by which those biosignatures can be transported to the surface—the inverse of the part of Objective 1 that explored ways that organics could reach the ocean from the surface. The principal means of transport are likely to be either convective i.

Although no active cryovolcanism has been detected on Titan yet, several features on the surface have been identified as potentially cryovolcanic. The transport to the surface could also create habitable environments along the way. When Mike Malaska refers to the deep subsurface, he's not just meaning the ocean , but reservoirs that could also exist in pockets along the pathways that organic material takes in and out of the ice shell. In particular, he says, between 7 and 30 kilometers beneath the surface, at the boundary between the stiff, brittle ice and the more ductile, softer ice, where temperatures and pressures would be somewhat similar to 2 or 3 kilometers beneath Antarctica, there could exist tiny spaces in between the ice grains of the ice shell where microbes such as Pelobacter acetylenicus could thrive.

Being closer to the surface than the ice shell could also mean that the resulting biomarkers from these pockets of subsurface life could reach the surface more easily. It also raises the question of how biosignatures could be chemically altered as they rise through the pathways in the ice shell , encountering different environments—liquid water, slushy ice, and solid ice—which would then impact upon what we could expect to detect on the surface.

Finally, once they do reach the surface, how will future missions to Titan detect these biomarkers? The ultimate goal of the investigation is to paint a picture of a potential biosphere on Titan, so that scientists know what to look for, and what to design instruments to detect, when we do return to Titan. Explore the Earth and beyond at www. More from Astronomy and Astrophysics.

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Your email address is used only to let the recipient know who sent the email. Here it is so cold degrees Fahrenheit or degrees Celsius that water ice plays the role of rock. No other world in the solar system, aside from Earth, has that kind of liquid activity on its surface.

The "sand" in these dunes is composed of dark hydrocarbon grains thought to look something like coffee grounds. In appearance, the tall, linear dunes are not unlike those seen in the desert of Namibia in Africa.

Titan has few visible impact craters, meaning its surface must be relatively young and some combination of processes erases evidence of impacts over time. Earth is similar in that respect as well; craters on our planet are erased by the relentless forces of flowing liquid water, in Earth's case , wind, and the recycling of the crust via plate tectonics. These forces are present on Titan as well, in modified forms. In particular, tectonic forces—the movement of the ground due to pressures from beneath—appear to be at work on the icy moon, although scientists do not see evidence of plates like on Earth.

Our solar system is home to more than moons, but Titan is unique in being the only moon with a thick atmosphere. At the surface of Titan, the atmospheric pressure is about 60 percent greater than on Earth—roughly the same pressure a person would feel swimming about 50 feet 15 meters below the surface in theocean on Earth. Because Titan is less massive than Earth, its gravity doesn't hold onto its gaseous envelope as tightly, so the atmosphere extends to an altitude 10 times higher than Earth's—nearly miles kilometers into space.

Titan's atmosphere is mostly nitrogen about 95 percent and methane about 5 percent , with small amounts of other carbon-rich compounds. The pieces of these molecules recombine to form a variety of organic chemicals substances that contain carbon and hydrogen , and often include nitrogen, oxygen and other elements important to life on Earth.

Some of the compounds produced by that splitting and recycling of methane and nitrogen create a kind of smog—a thick, orange-colored haze that makes the moon's surface difficult to view from space. Spacecraft and telescopes can, however, see through the haze at certain wavelengths of light outside of those visible to human eyes.