Eris: The Dwarf Planet

Eris is a dwarf planet located in the outer regions of our solar system. It was first discovered in 2005 by a team of astronomers led by Mike Brown, Chad Trujillo, and David Rabinowitz. Eris is named after the Greek goddess of strife and discord, fitting for a celestial body that played a key role in the reclassification of what constitutes a planet.

Physical Characteristics of Eris

Eris has a diameter of about 2,326 kilometers, making it slightly smaller than Pluto. It has a highly elliptical orbit, which takes it as close as 38.2 astronomical units (AU) to the sun and as far as 97.6 AU. Eris takes approximately 557 Earth years to complete one orbit around the sun.

Its surface is primarily composed of rock and a significant amount of frozen water ice. Eris has a thin atmosphere primarily composed of nitrogen, and possibly trace amounts of methane. Its surface is covered in frozen methane and nitrogen, giving it a highly reflective surface that makes it one of the brightest objects in the Kuiper Belt.

Impact on Planetary Classification

One of the most significant impacts of Eris' discovery was the debate it sparked about the definition of a planet. Its discovery prompted the International Astronomical Union (IAU) to reconsider what constitutes a planet, ultimately leading to the reclassification of Pluto as a "dwarf planet" and the creation of a new category of celestial objects.

Study Guide

Here are some key points to focus on when studying Eris:

1. Describe the physical characteristics of Eris.
2. Explain the significance of Eris' discovery in the reclassification of Pluto.
3. Compare and contrast Eris with other dwarf planets in the Kuiper Belt.
4. Analyze the potential for future exploration missions to Eris and the challenges they may pose.

Understanding Eris and its role in reshaping our understanding of planetary classification is crucial to comprehending the dynamic nature of scientific knowledge and discovery in our solar system.