Titan is the largest moon of Saturn and the second-largest in the Solar System. It is the only moon known to have an atmosphere denser than the Earth's and is the only known object in space—other than Earth—on which clear evidence of stable bodies of surface liquid has been found. Titan is one of seven gravitationally rounded moons of Saturn and the second-most distant among them. Frequently described as a planet-like moon, Titan is 50% larger in diameter than Earth's Moon and 80% more massive. It is the second-largest moon in the Solar System after Jupiter's Ganymede and is larger than Mercury; yet Titan is only 40% as massive as Mercury, because Mercury is mainly iron and rock while much of Titan is ice, which is less dense.
Cassini–Huygens, commonly called Cassini, was a space-research mission by NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a space probe to study the planet Saturn and its system, including its rings and natural satellites. The Flagship-class robotic spacecraft comprised both NASA's Cassini space probe and ESA's Huygens lander, which landed on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit, where it stayed from 2004 to 2017. The two craft took their names from the astronomers Giovanni Cassini and Christiaan Huygens.
Enceladus is the sixth-largest moon of Saturn and the 19th-largest in the Solar System. It is about 500 kilometers in diameter, about a tenth of that of Saturn's largest moon, Titan. It is mostly covered by fresh, clean ice, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon reaches only −198 °C, far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide variety of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrain.
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected.
In fluid dynamics, a wind wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result of the wind blowing over the water's surface. The contact distance in the direction of the wind is known as the fetch. Waves in the oceans can travel thousands of kilometers before reaching land. Wind waves on Earth range in size from small ripples to waves over 30 m (100 ft) high, being limited by wind speed, duration, fetch, and water depth.
Ontario Lacus is a lake composed of methane, ethane and propane near the south pole of Saturn's moon Titan. Its character as a hydrocarbon lake was confirmed by observations from the Cassini spacecraft, published in the 31 July 2008 edition of Nature. Ontario Lacus has a surface area of about 15,000 square kilometers (5,800 sq mi), about 20% smaller than its terrestrial namesake, Lake Ontario in North America. In April 2012, it was announced that it may be more like a mudflat or salt pan.
Sunglint is a phenomenon that occurs when sunlight reflects off the surface of the ocean at the same angle that a satellite or other sensor is viewing the surface. In the affected area of the image, smooth ocean water becomes a silvery mirror, while rougher surface waters appear dark. Sometimes the sunglint region of satellite images reveals interesting ocean or atmospheric features that the sensor does not typically record.
Saturn's largest moon Titan is one of several candidates for possible future colonization of the outer Solar System, though protection against extreme cold is a major consideration.
Whether there is life on Titan, the largest moon of Saturn, is currently an open question and a topic of scientific assessment and research. Titan is far colder than Earth, but of all the places in the Solar System, Titan is the only place besides Earth known to have liquids in the form of rivers, lakes, and seas on its surface. Its thick atmosphere is chemically active and rich in carbon compounds. On the surface there are small and large bodies of both liquid methane and ethane, and it is likely that there is a layer of liquid water under its ice shell. Some scientists speculate that these liquid mixes may provide prebiotic chemistry for living cells different from those on Earth.
Lakes of liquid ethane and methane exist on the surface of Titan, Saturn's largest moon. This was confirmed by the Cassini–Huygens space probe, as had been suspected since the 1980s. The large bodies of liquid are known as maria (seas) and the small ones as lacūs (lakes).
The climate of Titan, the largest moon of Saturn, is similar in many respects to that of Earth, despite having a far lower surface temperature. Its thick atmosphere, methane rain, and possible cryovolcanism create an analogue, though with different materials, to the climatic changes undergone by Earth during the far shorter year of Earth.
Kraken Mare is the largest known hydrocarbon sea on the surface of Saturn's moon Titan. It was discovered by the space probe Cassini in 2006, and was named in 2008 after the Kraken, a legendary sea monster. It covers an area slightly bigger than the Caspian Sea on Earth, making it the largest known lake in the Solar System.
Ligeia Mare is a lake in the north polar region of Titan, the planet Saturn's largest moon. It is the second largest body of liquid on the surface of Titan, after Kraken Mare. Larger than Lake Superior on Earth, it is mostly composed of liquid methane, with unknown but lesser components of dissolved nitrogen and ethane, as well as other organic compounds. It is located at 78° N, 249° W, and has been fully imaged by the Cassini spacecraft. Measuring roughly 420 km (260 mi) by 350 km (217 mi) across, it has a surface area of about 126,000 km2, and a shoreline over 2,000 km (1,240 mi) in length. The lake may be hydrologically connected to the larger Kraken Mare. Its namesake is Ligeia, one of the sirens in Greek mythology.
Titan Mare Explorer (TiME) is a proposed design for a lander for Saturn's moon Titan. TiME is a relatively low-cost, outer-planet mission designed to measure the organic constituents on Titan and would have performed the first nautical exploration of an extraterrestrial sea, analyze its nature and, possibly, observe its shoreline. As a Discovery-class mission it was designed to be cost-capped at US$425 million, not counting launch vehicle funding. It was proposed to NASA in 2009 by Proxemy Research as a scout-like pioneering mission, originally as part of NASA's Discovery Program. The TiME mission design reached the finalist stage during that Discovery mission selection, but was not selected, and despite attempts in the U.S. Senate failed to get earmark funding in 2013. A related Titan Submarine has also been proposed.
Punga Mare is a lake in the north polar region of Titan, the planet Saturn's largest moon. After Kraken Mare and Ligeia Mare, it is the third largest known body of liquid on Titan. It is composed of liquid hydrocarbons. Located almost adjacent to the north pole at 85.1° N, 339.7° W, it measures roughly 380 km (236 mi) across, greater than the length of Lake Victoria on Earth. Its surface area is ~61,000 km2. Its namesake is Punga, in Māori mythology ancestor of sharks, rays and lizards and a son of Tangaroa, the god of the sea.
Jingpo Lacus is a lake in the north polar region of Titan, the planet Saturn's largest moon. It and similarly sized Ontario Lacus are the largest known bodies of liquid on Titan after the three maria. It is composed of liquid hydrocarbons. It is west of Kraken Mare at 73° N, 336° W, roughly 240 km long, similar to the length of Lake Onega on Earth. Its namesake is Jingpo Lake, a lake in China.
Mayda Insula is an island in the Kraken Mare, a body of liquid composed primarily of methane, on Saturn's largest moon Titan. Mayda Insula is the first island (insula) to be named on a planet or moon other than Earth.
The geology of Titan encompasses the geological characteristics of Titan, the largest moon of Saturn. Titan's density of 1.881 g/cm3 indicates that it is roughly 40–60% rock by mass, with the rest being water ice and other materials. It is differentiated into a rocky core, liquid water ocean, and an icy shell; the core and ocean may be partitioned by a layer of exotic high-pressure ices, and the icy shell may have a chemically distinct surface crust.
