|Universe||Star Wars Universe|
|Region||Outer Rim Territories|
|Class||Terrestrial (desert world)|
|Notable Species||Jawas, Tusken Raiders, "mole creatures", Trooshti, Dewbacks, Profoggs, Krayt Dragons, Banthas, Eopies, Rontos et cetera|
|Rotation period||23 standard hours|
|Orbital Period||304 local days|
Tatooine is a desolate desert world and the innermost planet in the binary star system Tatoo, located in the Outer Rim Territories of the galaxy. A very ancient world, paleontological evidence suggest that Tatooine was once covered by vast oceans and had a much more humid climate. Today, however, the planet is very arid, and liquid water covers no more than 1% of its surface. Due to the harsh environment and the unbearable heat and brightness caused by the two suns, the planet's population is concentrated in a relatively mild area on the northern hemisphere. The equatorial region is believed to be completely uninhabited.
Despite its hostile climate, Tatooine is home to a great variety of native lifeforms, including three sapient rodentoid species: the Jawas, the Tusken Raiders and the so-called "mole creatures"; and a poorly-known insectoid race known as the Trooshti. Besides these native species, the planet is inhabited by Humans and many other species from all over the galaxy. Tatooine is one of the many worlds politically controlled by the Hutts. The planet is also notable for being home to one of the most feared figures of the galaxy: the evil sith lord Darth Vader.
In ancient times, Tatooine was a lush world inhabited by a technologically-advanced rodentoid race known as the Kumumgah. However, the planet was conquered by the hostile imperialist Rakata, who were later defeated and forced out by the native Kumungah. As a response, the Rakata used their impressive technology to bombard the planet, fusing the silicates of the soil into glass and evaporating the surface water. Through the eons, the glassy soil suffered erosion and became sand. The surviving Kumungah were divided into two extremely different species: the Jawas and the Tusken Raiders (also known as Ghorfas or Sandpeople). It is possible that the subterranean "mole creatures" are also descendants of the Kumungah.
Tatooine is thought to have been one of the oldest planets in known space and was composed of a molten core with a rocky mantle and silicate rock crust. Fossil records suggest Tatooine was once covered in large oceans, which dried up, leaving behind many pre-arid geological formations, including Beggar's Canyon, formed around 2,000,000 BBY, when Tatooine was lush. Other notable geological features included the Dune Sea, enormous sodium-rich desert, Mushroom Mesa, a vast formation of giant standing stones, and the Jundland Wastes, a rocky region. There was a settlers' saying that one's eyes burn out faster by staring straight and hard at sun-scorched flatlands than by looking directly at the suns.
Tatooine orbited two suns, Tatoo I and Tatoo II and was covered in deserts and rock formations, so the days were extremely arid and bright, especially during double noon. In fact, it was so brightly lit by the suns from space it could appear to be a star itself. This was the case for the people who discovered Tatooine as they first thought Tatooine was in fact a star until they approached and discovered that it was a desert planet. The planet circled the suns far enough to develop a stable, but very hot climate. Due to the extreme conditions, only a relatively mild region of its northern hemisphere was habitable, and less than 1% of the planet was covered in surface water. The average humidity level was 5.4%.
One of the many extraordinary features unique to Tatooine was the mysterious mists, which rose regularly from the ground where desert sands met cliffs and mesas. Various theories of this moisture's origin were disputed by meteorologists and geologists, like water suspended in sandstone veins beneath the sand and complex chemical reactions which made it rise when the ground cooled, then fall underground again with the double sunrise.
Tatooine's harsh arid climate caused Humans to show signs of accelerated aging.
The atmosphere could not have had helium, as it would have killed any mynocks that lived there.