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Sedna (dwarf planet)

Adapted from Wikipedia · Explorer experience

Animation showing the dwarf planet Sedna moving across the night sky, captured by a sky survey telescope in 2005.

What is Sedna?

Sedna is a special kind of space object called a dwarf planet. It lives in the farthest parts of our Solar System, much farther out than even Neptune. Sedna takes about 11,400 years to travel around the Sun!

How was Sedna found?

Sedna was discovered in 2003 by scientists using a telescope at the Palomar Observatory near San Diego, California. They noticed something moving slowly in the sky and realized it was very far from the Sun.

Why is Sedna special?

Sedna has a very stretched-out path around the Sun. Its surface is made of frozen water, carbon dioxide, and other ices, giving it a reddish color. Scientists think Sedna might belong to a distant group of objects called the scattered disc or the inner Oort cloud. Studying Sedna helps us learn more about how our Solar System formed long ago.

Images

An illustration showing the orbit of the distant object Sedna in our solar system, with the Sun and planets like Jupiter, Saturn, Uranus, and Neptune visible as of January 1, 2017.
A chart showing how bright Sednoid objects appear from Earth over 11,000 years.
Diagram showing the orbits of distant space objects called Sednoids, including Sedna, 2012 VP113, and 2015 TG387.
A colorful image of Ceres, showing bright craters like Haulani and Oxo on its surface.
A true-color image of the planet Pluto, showing its icy surface and famous 'heart' region as captured by NASA's New Horizons spacecraft in 2015.
A visual guide to the major objects in our Solar System, showing the relative sizes of the planets and the Sun.
A colorful montage showing the planets in our solar system—Mercury, Venus, Earth with its Moon, Mars, Jupiter, Saturn, Uranus, and Neptune—all taken by NASA spacecraft.
A stunning view of our planet Earth as seen from the Apollo 17 spacecraft during its journey to the Moon.
A stunning view of Earth rising over the lunar horizon, as seen by astronauts during the Apollo 8 mission.

Related articles

Dwarf planet
Solar System
Neptune
Carbon dioxide
Scattered disc
Oort cloud

This article is a child-friendly adaptation of the Wikipedia article on Sedna (dwarf planet), available under CC BY-SA 4.0.

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