With Pluto’s demotion to a “dwarf planet,” the solar system was left with 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. It now seems that the number 8 may not survive for long, as researchers are now searching for a 9th planet that they think exists in the far-away outer solar system. This elusive “Planet 9” was first postulated in 2015 by Caltech astronomers Konstantin Batygin and Mike Brown. These astronomers saw noticed the strange orbits of some Kuiper Belt objects which could be explained by the gravitation influence of a large planet. This planet would be likely similar to the “ice giants” Uranus and Neptune, given its great distance from the warmth of the sun. Theories about why it is so far away range greatly. One such theory is that it was a giant planet which was thrown to the outer solar system after it encountered Jupiter during the formation of the solar system. Another theory is that it is a planet which was captured from another star! While Pluto may not be thought of as a proper planet anymore, perhaps we owe it some gratitude for drawing our attention to the outer solar system, something which might lead us to discover the true 9th planet. What a day for Astronomy (and Astrology) that will be if such a planet is found!