Pluto vs. Sedna

Attribute	Pluto	Sedna
Distance from Sun	5.9 billion km	13.6 billion km
Orbital Period	248 years	11,400 years
Diameter	2,377 km	1,600 km
Discovery Date	1930	2003

Physical Characteristics

Pluto, once considered the ninth planet in our solar system, is now classified as a dwarf planet. It has a diameter of approximately 1,473 miles, making it smaller than Earth's moon. Pluto is composed primarily of rock and ice, with a thin atmosphere of nitrogen, methane, and carbon monoxide. In contrast, Sedna is a trans-Neptunian object located in the outer reaches of the solar system. It has a diameter of about 620 miles, making it smaller than Pluto. Sedna is believed to be composed of rock and ice, similar to Pluto.

Orbital Characteristics

Pluto orbits the sun at an average distance of 3.7 billion miles, taking about 248 Earth years to complete one orbit. Its orbit is highly elliptical, meaning that it can come closer to the sun than Neptune during certain periods. Sedna, on the other hand, has a highly elliptical orbit that takes it as far as 84 billion miles from the sun at its most distant point. It takes Sedna approximately 11,400 years to complete one orbit around the sun, making it one of the longest orbital periods of any known object in the solar system.

Discovery and Naming

Pluto was discovered in 1930 by American astronomer Clyde Tombaugh. It was named after the Roman god of the underworld. Sedna, on the other hand, was discovered in 2003 by a team of astronomers led by Mike Brown. It was named after the Inuit goddess of the sea. Both Pluto and Sedna have mythological names that reflect their distant and mysterious nature.

Surface Features

Pluto's surface is characterized by a variety of geological features, including mountains, plains, and valleys. One of the most prominent features on Pluto is the heart-shaped region known as Tombaugh Regio. This region is believed to be a large glacier of nitrogen ice. Sedna's surface, on the other hand, is largely unknown due to its extreme distance from Earth. It is thought to be covered in a layer of frozen methane and other volatile compounds, similar to Pluto.

Atmospheres

Pluto has a thin atmosphere that is primarily composed of nitrogen, with traces of methane and carbon monoxide. This atmosphere is believed to be in a constant state of change due to Pluto's elliptical orbit and distance from the sun. Sedna, on the other hand, is thought to have a very tenuous atmosphere, if it has one at all. Its distance from the sun makes it unlikely to retain a significant atmosphere, unlike Pluto.

Potential for Exploration

Pluto has been visited by a spacecraft, the New Horizons probe, which conducted a flyby of the dwarf planet in 2015. The data collected by New Horizons has provided valuable insights into Pluto's geology, atmosphere, and composition. Sedna, on the other hand, has not been visited by any spacecraft and remains a distant and enigmatic object in the outer solar system. Due to its extreme distance from Earth, it is unlikely that Sedna will be explored in the near future.