Titan is the second biggest moon in our solar system, greater than the planet Mercury. Ganymede, Jupiter's moon, is somewhat bigger (by about 2 percent). Titan's atmosphere is mainly nitrogen, just like Earth's, but it has a surface pressure that is 50% greater. The other big moon, Mercury, does not have an atmosphere.
Titan was once like Earth itself: It had an ocean of water underneath its crust. But over time, most of this water was lost when Titan evolved into its current state. What remains today is a thick layer of ice on Titan's mantle.
Titan is more massive than Earth's moon, but not by much. If we were to make Titan into a sphere, it would be less than 8-9 miles (13-14 kilometers) in diameter. This would make it slightly smaller than Earth's moon, which is 938 miles (1.5 km) across.
Titan has a dense atmosphere made up of nitrogen and methane with some hydrogen added for flavor. There is so much methane in Titan's atmosphere that even if all of it were to disappear, there would still be more than enough nitrogen left over for another million years.
The atmosphere of Titan is so thick that clouds form around anything living on the moon's surface: Trees, animals, cities. These clouds are composed of liquid methane and sometimes include rain or snow.
Titan is Saturn's biggest moon and the solar system's second largest (after Ganymede of Jupiter). It is the solar system's only moon with clouds and a thick, planet-like atmosphere. The atmosphere contains more than 100 times as much gas as Earth's, making it the most voluminous in the Solar System.
Titan was originally thought to be a large asteroid that got incorporated into Saturn's orbit. But in 2004, scientists discovered that it has an ocean of liquid methane under its surface, which would be sufficient to make it a planet itself.
Titan is so big that it completely fills Saturn's orbital radius, meaning that one day on Titan is equal to one year on Earth. However, because Saturn takes 10 years to complete one rotation, there are 14 days on Titan and 14 nights off-world.
The name "Titan" comes from the Greek god of medicine, Asclepius. Asclepius was known for his knowledge of healing, and some say that he received this knowledge from the goddess Athena. So, the name "Titan" came to mean "the knower of many things."
There are several moons in our solar system that are larger than Titan, but they're also mostly made of rock and thus not very interesting to study.
Titan is our solar system's second biggest moon. Titan is larger than Earth's moon and even the planet Mercury. It has a mass about 17 times that of Earth's Moon and it circles Saturn every six days.
Titan is also very rich in nitrogen. There is more nitrogen on Titan than anywhere else in our solar system except for within the planets themselves. Nitrogen is important because everything in life requires it: proteins, DNA, muscles, bones, and neurons are all made of nitrogen, as are bullets and bombs. Nitrogen doesn't kill humans, but it does make them die. That's why astronauts on space missions must avoid giving birth while in orbit around the Sun. Their babies would be born without enough oxygen to survive.
Titan has great pits full of organic materials that may have been caused by meteorites. These pits are what first suggested that Titan might have once supported itself as a tropical ocean world with hydrothermal vents similar to those on Earth.
Titan's atmosphere is made mainly of nitrogen (with some methane) with some smaller amounts of other gases such as hydrogen, oxygen, and traces of ammonia. This makes Titan the most nitrogen-rich environment on Earth or any other planet outside of earth.
Titan has a diameter that is half that of Earth's moon, making it one of the solar system's biggest natural satellites. Titan's most noticeable feature is its dense, foggy atmosphere. Nitrogen is the most prevalent gas, with methane and ethane clouds and a dense organic haze. It has a very faint hue, almost an orange-brown.
Titan has a complex interior made up of layers from different times in its history. The onion-like shell is a solid crust about 500 miles thick. Beneath this is a massive liquid ocean that may be as deep as 2300 miles. This is surrounded by a rocky mantle about 20 miles thick. Above this is a thin veneer of ice on top of a larger body of frozen nitrogen.
Titan has a surface temperature of -180 degrees Celsius (or -292 degrees Fahrenheit). There is no evidence of any internal heat source to account for this; instead, it appears to be due to sunlight heating the planet up from below.
The energy from the sun that reaches Titan is reduced by more than ninety percent because it has to pass through Earth's atmosphere before reaching the surface. So only a small part of this energy is actually used by Titan itself.
Most of the energy is radiated back into space. Only about five percent gets absorbed by the atmosphere and converted to thermal energy which then becomes available to power geological processes.