etäehtojen

Etäehtojen are celestial bodies that orbit a star at a greater average distance than the outermost planet of a planetary system. They are typically composed of ice and rock, and are often referred to as trans-Neptunian objects (TNOs) when they orbit beyond Neptune. The most well-known etäehtö is Pluto, which was reclassified as a dwarf planet in 2006. Other notable etäehtö include Eris, Sedna, and Makemake. These objects are of great interest to astronomers due to their potential to provide insights into the formation and evolution of the solar system. Some etäehtö are also believed to be the source of short-period comets, which are comets that orbit the Sun in less than 200 years. The study of etäehtö is an active area of research, with new discoveries being made regularly.