NASA's Saturn spacecraft Cassini regularly captures images of Saturn's moon Titan. Images of its surface are used to monitor any changes that occur during the course of its space missions.
Scientists use the data to understand Earth-like phenomenon on Titan like dune formation and wind. Earlier this year, Cassini's images of Titan's surface reveal vast dune lands filled with hydrocarbon sands.
Two dune-filled regions Aztlan (south) and Fensal (north), create a dark, H-shaped area that is largely visible from space. The image was taken on July 25, 2015 via Cassini's narrow-angle camera at a distance of about 450,000 miles from Titan.
Saturn's moon Titan could pass as Earth's alien twin due to similar but slightly extraterrestrial characteristics. Titan has clouds, lakes and rain but they are made of ethane and methane. Like Earth, Titan has a solid surface but it is made of water ice. Sand dunes on Earth are majestic sights. Titan has dune fields too, but they're filled with hydrocarbon sands.
But unlike Earth, the Sun's light barely reaches the Saturn's icy moon. The thickness of Titan's atmosphere is twice that of Earth. On this moon, global warming does a lot of good. The greenhouse gas effect of its methane-rich atmosphere keeps the moon at a balmy negative 179 degrees Celsius. Without methane's greenhouse gas effect, it would definitely be colder than it is now. Amazingly, despite having a thick atmosphere, Titan has very few clouds that shower methane on the moon's surface.
Here on Earth, methane is typically present in its gaseous state or frozen state underneath the sea surface. On icy Titan, methane can be found in liquid form and drops from the skies through the clouds because of its temperature - a freezing 179 degrees Celsius. The methane rain creates drainage channels that snake across bedrocks made of water and ice. In the polar regions of the moon, liquid methane can be found in massive lakes and standing ponds.
Saturn's moon Titan and the Earth are the only two worlds in our solar system with known seas and lakes found on its surface.
On Nov. 13, NASA's Cassini spacecraft will get closer to Titan's surface at 7,406 miles. The Cassini space mission is a collaboration between NASA, the Italian Space Agency and the European Space Agency.