Eris: The Dwarf Planet Beyond Pluto

Have you ever heard of a dwarf planet called Eris? It's a fascinating celestial body located in the Kuiper Belt, a region beyond Neptune filled with icy objects. Eris is so far away from the sun that it takes 557 Earth years to complete one orbit!

Key Facts about Eris:

• Size: Eris is slightly larger than Pluto, making it the largest dwarf planet in our solar system.
• Distance from the Sun: Eris is about 96 astronomical units (AU) from the sun. One AU is the average distance between the Earth and the sun.
• Discovery: Eris was discovered in 2005 by a team of astronomers at the Palomar Observatory in California.
• Moon: Eris has one moon named Dysnomia.
• Temperature: Due to its extreme distance from the sun, Eris has a very cold surface temperature of about -387 degrees Fahrenheit (-232 degrees Celsius).

Why is Eris a Dwarf Planet?

Eris was initially considered a tenth planet in our solar system. However, in 2006, the International Astronomical Union (IAU) redefined the definition of a planet. To be classified as a planet, an object must meet three criteria:

1. It must orbit the sun.
2. It must be massive enough for its own gravity to pull it into a nearly round shape.
3. It must have cleared its neighborhood of other objects.

Eris, like Pluto, failed to meet the third criterion. It shares its orbital region with other icy objects, which is why it was reclassified as a dwarf planet.

Exploring Eris:

Because of its extreme distance from Earth, Eris is very difficult to study. However, astronomers are using telescopes and spacecraft to learn more about this fascinating dwarf planet. The New Horizons spacecraft, which flew past Pluto in 2015, is providing valuable data that is helping scientists understand the Kuiper Belt and the objects within it.

Fun Facts:

• Eris is named after the Greek goddess of discord and strife.
• Eris's moon, Dysnomia, is named after the Greek goddess of lawlessness.
• Eris is so far away from the sun that it takes sunlight about 10 hours to reach it.

So next time you look up at the night sky, remember that beyond the familiar planets lies a vast and unexplored realm filled with fascinating objects like Eris. Keep exploring and learning about the wonders of our solar system!