Martian Martian A Martian is a native inhabitant of the planet Mars. Although the search for evidence of life on Mars continues, many science fiction writers have imagined what extraterrestrial life on Mars might be like. Some writers also use the word "Martian" to describe a human colonist on Mars. The earliest known instances of the word "Martian", used as a noun instead of an adjective, were printed in late 1877. They appeared nearly simultaneously in England and the United States, in magazine articles detailing Asaph Hall's discovery of the moons of Mars in August of that year. The next event
Planet Nine perihelia also reached values where the objects would not be observed, requiring a population of Sednas significantly larger than current estimates. They then, after declining, fell to values low enough for the objects to enter planet-crossing orbits leading to their ejection from the Solar System, requiring an initial population inconsistent with current models of the early Solar System to explain current observations. Based on these challenges Shankman et al. concluded that the existence of Planet Nine is unlikely and that the currently observed alignment of the existing TNOs is a temporary phenomenon that will disappear as more objects are detected.