Explore the history of planets, asteroids and dwarf planets. Describe the discussions and reasons behind the classification of planets with reference to the size of Eris. Official decisions regarding the planetary status come from the International Astronomical Union.
Eris's motions against the background of stars led to its discovery. Explore the techniques that astronomers use to detect and study objects. Examine the reason behind the fact that astronomers failed to discover Eris before 2005. By discussing the reason why the reflecting telescope at Mount Palomar Observatory, California, failed to detect Eris in 2003, you gain insights into the problems with astronomical research.
Study the position of Eris and the objects in its orbits, and explore the differences and similarities between Eris and the other dwarf planets. It is difficult to estimate the size of objects in space and a dot of light is often the first sign of an object in space. Comparing Eris with other planets and various objects in our solar system leads to a deeper understanding.of problems related to determining the size of an object. Astronomers compare the heat coming from an object. Evaluate this method by referring to the heat from a fire or matchstick. The online site Exploratorium has ideas and tips about how to build a solar system. However, calculations need to be made to include Eris. Use the calculations to construct a model with all the planets' and dwarf planets' positions.
Use theories about the composition of Eris to explore the conditions on this dwarf planet. Compare its color and temperature with other dwarf planets and try to build a picture of the conditions on Eris. Try to guess what the interior looks like by referring to the possible interior structure of Pluto.