Lantea

Lantea is a planet in the Pegasus Galaxy, which became famous as the location of Atlantis. Before the real name of the planet was known to the Atlantis Expedition, Lieutenant Aiden Ford suggested naming the planet "Atlantica", which was denied by then-Major John Sheppard.

Overview
Lantea is one of only two known planets in its solar system which has an atmosphere capable of sustaining human life. It is mainly covered with a large ocean, although a single landmass exists which covers roughly 15 million square miles.

There exists at least three animal life forms on the planet; a whale-like fish, called Flagisallus by the Ancients, a giant lobster-like creature that is approximately the size of a Buick, the name of which is unknown, and a fish remarkably similar to a Terran trout. During its entire history, no intelligent life has developed, although the Flagisallus does show signs of intelligence.

Life on the planet is threatened by two great dangers. First, every 20 years the ocean gets unusually warm, which causes the development of powerful storms that can cover nearly 20% of the planet and cause great destruction. Another great danger is a coronal mass ejection of the planets sun which happens about every 15,000 years, and is capable of destroying all life on the planet, but the Ancients in former times prevented this by expanding the shield of the city to cover a great portion of the planet. Nevertheless, the areas unprotected by the shield suffered damage so extreme that it caused the extinction of several species.

History
After the Ancients left Earth between 5,000,000 to 10,000,000 years ago they finally settled their city on a planet in the Pegasus galaxy which they called Lantea. There Atlantis was sitting as an island on the water and from this planet the Ancients started to explore their new home galaxy, seeded life on planets and built a whole new network of Stargates, this time using a new design. To protect their new home the Ancients built a large network of defense satellites stationed all across the Lantean system. To have an alternative power source for their city the Ancients also built a moving geothermal energy drilling station on the ocean floor.

While exploring the galaxy the Ancients, which were called the Lanteans in this galaxy, encountered creatures called Iratus Bugs. These creatures fed on humans, and the mix of human DNA with Iratus DNA while the bug was going through egg laying cycles caused mutations to the offspring. Generations of these mutations resulted in a race called the Wraith, which soon started to take over the galaxy. This started a 100 year long war with the Ancients. During this war, the Wraith sent many ships to Lantea to destroy Atlantis. On their way, they destroyed the whole satellite network, save for one, and attacked the city from orbit. The Ancients were able to repel the attacks. However, unknown to them, one Wraith cruiser from the first attack wave survived and crash landed into the ocean where it lay dormant for over 10,000 years. Finally, the Ancients submerged Atlantis under the ocean and left the city for their old home, Earth.

10,000 years later, Atlantis was discovered by the Atlantis expedition from Earth which now inhabits the city. Later the mainland became home to the Athosians, humans from the Pegasus galaxy that were later resettled on a new planet by the Ancients of the warship Tria, who returned to Atlantis and were subsequently killed by the Asurans.

After controlling the city for about three years, the Asurans attacked Atlantis with a beam weapon through a Stargate in orbit. This weapon was capable of following the city anywhere on the surface of Lantea, and it was determined that the only way to escape was to use of the stardrive to fly the entire city to another world, where the Asurans would not be able to follow them. Lantea was abandoned with the intended final destination of M12-578 as its new home planet. However, Atlantis was damaged in the attempt and dropped out of hyperspace far from the new planet with many of the crew hurt and with only 24 hours power remaining. After a daring heist on the Asuran homeworld, during which Dr. Elizabeth Weir was captured along with the knowledge of M12-578, Atlantis was flown to another world with a habitable ocean: M35-117, which Dr. Weir did not know about.