Of Saturn’s 53 known moons, Titan is the largest and is also the second largest moon in our solar system. It’s also the only moon that has a cloud system and a dense atmosphere that is similar to what a planet would have.
That’s saying a lot since we have identified around 150 known moons. Titan is bigger than the planet Mercury. In fact, if it was orbiting the sun it would be considered to be a planet.
Scientists refer to Titan as the “most Earth-like world that we have found to date.” Titan has a surface covered in liquid hydrocarbons such as ethane and methane that form lakes, rivers, and seas.
The biggest seas are as wide as hundreds of miles and hundreds of feet deep. Titan has thick crust of water ice and scientists think that there is even liquid water underneath it.
The atmosphere is made up of mostly nitrogen, but the pressure on Titan is 50% higher than that on Earth.
Given all of these conditions, Titan is a moon that scientists are looking at for potential life.
Of course, if there is life on Titan, it would be different than what we have on Earth because it would use a different type of chemistry. Until it’s verified, astronomers are unsure if Titan is lifeless or has an unknown type of lifeform.
Discovered By: Christiaan Huygens
Discovery Date: March 25, 1655
Diameter: 5,149.4 km
Mass: 1.35 × 10^23 kg (1.8 Moons)
Orbital Period: 15.9 days
Orbit Distance: 1,221,865 km
Surface Temperature: – 40 degrees C
Titan can’t be seen with the naked eye. In 1655, Titan was discovered by the Dutch astronomer, Christiaan Huygens, who used a telescope that was advanced for its time.
In 1944, 300 years later, Gerard Kuiper, a Dutch-American astronomer made the discovery of some of Titan’s special characteristics. Kuiper passed sunlight that was reflected from Titan through a spectrometer and detected methane gas.
As he studied Titan, he recognized that the moon had a hazy dense atmosphere.In 1979, the Pioneer 11 spacecraft was sent to explore Titan. Pioneer 11 confirmed the research that scientists had previously done on the temperature and mass of Titan.
They had also correctly predicted that the spacecraft would be able to see hints of a bluish color in the upper atmosphere of Titan.Titan, like many objects in our solar system, took its name from Greek mythology.
The Titans were the oldest gods that ruled over the universe before the Olympians.
Formation, Structure and Surface:
The atmosphere on Titan is believed to hold a clue as to how Titan was formed. When the NASA and European Space Agency Cassini-Huygens mission was sent to Titan it measured the atmosphere and found nitrogen-14 and nitrogen-15 isotopes.
The isotope ratio is very close to comets in the Oort Cloud, a place in the outer solar system where hundreds of billions of icy bodies orbit.
This information leads scientists to believe that Titan was formed around the same early creation time as our sun and that it formed in the cold dust and gas disk like our sun, instead of the warmer material that formed Saturn.
Scientists are unsure what the interior of Titan looks like, but computer models that have been based on Cassini-Huygens data indicate that it may have 5 major layers.
The core, or innermost layer is made up of water-bearing silicate rock that has a diameter from 2,500-4,000 km. A shell of a special type of water ice called ice-VI surrounds the core. Ice-VI is water ice that can only be found in pressures that are extremely high.
The ice-VI has a salty liquid layer that surrounds it and that sits on a water ice outer crust. It’s thought that there are organic molecule on the surface that have settled there from the atmosphere in the form of liquids and sands or arrived when it rained.
The pressure on Titan is around 60% greater than that of Earth, and if you were standing on the surface of Titan it would feel like you are underwater on Earth around 50 ft/15 m.
Scientists consider the surface of Titan to be as close to that of Earth that we have found so far in the solar system. Of course, the chemistry is completely different and the temperatures on Titan are very cold.
The average Titan temperatures range are around -290 degrees F/-179 degrees C and is so cold that instead of rock like we have on Earth, Titan has ice.
If Titan does have any volcanic activity instead of the molten rock or lave that Earth has, Titan’s “lava” would be liquid water. The surface of Titan has evidence of a lot of river channels that were carved by ethane and methane.
There are large lakes filled with natural gas, giving the kind of surface liquid activity on Titan second only to Earth.
Titan has dark dune areas that stretch out across the equator area of its landscape. The “sand” dunes contain dark hydrocarbon grains that are believed to look a bit like coffee grounds.
If you looked at the dunes they might resemble the tall sand dunes of Africa. One of the things that scientists have noticed is that Titan doesn’t have very may impact craters that are visible.
This means that its surface must be somewhat young, as the moon’s renewal process covers over the impact evidence. On Earth, we have erosion, wind, and flowing water as well as new areas of lava or tectonic activity that covers over the evidence of some of the craters.
It’s thought that similar processes are happening on Titan, but in different ways. Titan’s underground activity is due to pressures from deep inside the moon, as scientists haven’t detected any of the type of tectonic plates that we have on Earth.
Titan has an incredible number of methane lakes that are located near the southern pole. In 2014, scientists found a feature on Titan that they have nicknamed “Magic Island.”
They believe that during some times the nitrogen bubbles that formed inside the oceans of Titan may be located on the surface and this creates a temporary island that will eventually fall apart. Planetary scientists have noted that Titan is the only world other than Earth that has stable liquid on its surface.
In the case of Titan, this liquid is ethane and methane seas, lakes, and rivers and Titan even has rain. Scientists are using Titan as an example of another type of hydrological cycle and are studying it as well as the Earth’s hydrological cycle.
The data and information received from spacecraft missions and Earth-based research suggests that there is a liquid ocean underneath Titan’s surface. This has yet to be completely confirmed, but it’s pretty exciting stuff.
The temperature on Titan is too cold for water ice to be on the surface but it may very well be underneath where temperatures are warm enough to melt the water ice.
Even though Saturn is far outside what scientists refer to as “the habitable zone,” it appears that Titan isn’t the only moon of Saturn that may have water beneath its surface.
Atmosphere and Magnetosphere:
Titan’s methane is in the form of a liquid but scientists think that this methane evaporates which forms clouds and even creates methane rain. There are clouds of cyanide gas and methane ice that are floating over the surface of Titan.
Scientists are astonished at how similar the natural processes of Titan are to Earth’s, even though the chemicals and materials are different.
Titan is an example of what they refer to as a “model of cloudy bodies,” which gives scientists a new view on alternative atmospheres that may look and act like those on Earth.
Saturn and its moons are at quite a distance from the sun and so the climate is driven by dim sunlight and low temperatures.
Using high tech telescopes, scientists have been able to detect and gauge activity in Titan’s atmosphere by looking at the sunsets.
The total atmosphere on Titan is around 95% nitrogen and 5% methane with other carbon-rich compounds in small amounts. The sun’s ultraviolet light splits apart the nitrogen and methane molecules and accelerates them into Saturn’s magnetic field.
These molecules dance around and reform into many different chemicals including hydrogen and carbon as well as the nitrogen and oxygen that we use as a gauge for the importance of life on our planet.
The smog or haze that surrounds Titan is created by some of the compounds that are split and reformed. Titan has an orange-colored thick haze that makes it very difficult to examine Titan from space.
Some telescopes and spacecraft do have the ability to peer into the various light wavelengths that expose information that we can’t see with the human eyes.
The 2004 Cassini mission discovered that the atmosphere of Titan extends out around 370 mi/600 km high.
Scientists have a difficulty figuring out if Titan has its own magnetic field. This confusion is based on the fact that the magnetosphere of Titan may be shielding the moon from the solar wind and influencing the magnetic fields in the atmosphere of the moon.
Could Life Exist?
Titan has an environment that is both similar and completely different than Earth’s, and yet as crazy as it sounds, Titan might be a place that could harbor life.
The basic requirements for life to form and thrive include liquid water, an energy source, and an atmosphere. Titan may have salty liquid water below its surface, does have an atmosphere, and has low-light from the sun.
Scientists have listed Titan as a potential location for life, although it would be below the surface and not life that we are familiar with.
Some scientists have conducted experiments using the type of UV radiation to create the kind of complex organic molecules that might be created from the atmosphere of Titan.
They have made the DNA and RNA and quite a few amino acids and proteins that are found in the atmosphere gases.
- Titan’s atmosphere is denser than that of Earth or Mars. It’s the only known moon to have a substantial atmosphere.
- The Cassini spacecraft did multiple flybys of Titan and found that the surface falls and rises by around 10 meters during one orbit. The shape changing is believed to be due to the movement of the moon’s crust as it orbits Saturn and is affected by Saturn’s gravity.
- Titan may have liquid on its surface but it isn’t water. The system of lakes, rivers and channels are filled with liquid hydrocarbons.
- On Earth we have volcanoes that spit out liquid rock in the form of lava. Scientists believe that Titan may have volcanoes but they spit out icy water and ammonia.
- Even though research has identified several mountains on Titan, none of them are very high.
- Scientists think the lake of high mountains on Titan may be due to the soft crust that Titan has that prevents the formation of high mountains.
- All of the mountains that have been found on Titan are named after mountains in J.R.R. Tolkien’s Middle-Earth. The Lord of the Rings trilogy has mountains whose names are now on Titan including: Angmar Mons, named after the Mountains of Angmar, Erebor Mons, named after Erebor [The Lonely Mountain], and Moria Mons, which is named after the Mountains of Moria.
- Titan has extensive sand dunes on its landscape and they are made up of organic soot. Some may be rock eroded by liquid methane and others are organic compounds that are from the atmospheric rain.
In the 1970s and 1980s the Voyager and Pioneer spacecraft did flybys of some of Saturn’s moons, supplying initial information and somewhat fuzzy images.
The 1997 Cassini spacecraft arrived at Saturn in 2004 and dropped the ESA Huygens probe on Titan to study the moon. The detailed data and images sent back allowed scientists to prioritize Titan as one of the moons to focus on.
The probe found mountains, complex organic chemistry, an atmosphere, seasonal changes, and a suspected subterranean ocean of water and ammonia.
Facts about Triton Moon for Kids:
- When looking at Titan, the first thing that you notice is its hazy and heavy atmosphere filled with a thick organic fog of nitrogen and its methane and ethane clouds.
- Titan has a diameter that is 50% bigger than our Earth’s moon and it is one of the largest moons in the solar system.
- Titan is made up of a surface of liquid hydrocarbon and has water ice on top of a possible rocky interior.
- Scientists think that Titan’s center core is hot and is surrounded by a layer of liquid water and ammonia.
- Titan and its parent planet, Saturn, are very close in age. Scientists think that Titan may have been created with left over materials from impacts when Saturn was first formed.