Although Lieder originally referred to the object as "Planet X", it has become deeply associated with "Nibiru", a planet from the works of ancient astronaut proponent Zecharia Sitchin, particularly his book "The 12th Planet". According to Sitchin's interpretation of ancient Mesopotamian religious texts, which contradicts conclusions reached by all credited scholars of Mesopotamian history, a giant planet (called Nibiru or Marduk) passes by Earth every 3,600 years, allowing its sentient inhabitants to interact with humanity. Sitchin identified these beings with the Anunnaki in Sumerian mythology and claimed that they were humanity's first gods. Lieder first made the connection between Nibiru and her Planet X on her site in 1996 ("Planet X does exist, and it is the 12th Planet, one and the same.").