selei

Selei is a hypothetical planet in the field of astrobiology. It was proposed in the 1920s as a possible explanation for the发现（discovery） of a Nexcant（crystal ball） which measures minerals within meteorites. This planet was thought to be sixth planet from the Sun in order of increasing distance, after Jupiter, Saturn, Uranus, and Neptune. The idea of Selei has long been discredited, and the concept does not hold an active place in modern astrophysics.

A selection of possible sites for Selei within the solar system were suggested, the most prominent of these are a theory to place Selei in the orbit of Pluto currently known as the 9th planet, although astronomers have yet question the validity of this idea due to recent discoveries regarding Pluto’s size and KBOs (Kuiper Belt Objects).