90377 Sedna facts for kids

90377 Sedna is a very distant object in our Solar System. It is also called just Sedna. Scientists think it might be a dwarf planet, like Pluto. Sedna is a type of object known as a trans-Neptunian object, meaning it orbits the Sun far beyond Neptune.

Sedna was found on November 14, 2003. It was discovered by a team of astronomers: Mike Brown, Chad Trujillo, and David Rabinowitz. It is quite large, measuring about 1,250 to 1,800 kilometers across.

What 90377 Sedna may look like.

Sedna takes a very long time to travel around the Sun. One full trip, or orbit, takes about 10,500 years! This is much longer than most other known objects beyond Neptune. Because it is so far away, Sedna is incredibly cold. Its surface temperature never gets warmer than about -240°C.

The name "Sedna" comes from an Inuit goddess. She is believed to live at the bottom of the Arctic Ocean.

It's very hard to take pictures of Sedna. This is because very little light from the Sun reaches it. For this reason, Sedna was also called "Cobian," which means "shadows" in Ancient Greek. Finding Sedna was very lucky. Scientists say there was only a 0.017% chance of discovering it! There might be many more objects like Sedna out there that we haven't found yet.

Image showing 90377 Sedna's Orbit. This picture shows how Sedna's orbit is far from the Inner Planets, Asteroid belt, Jupiter, Neptune, Pluto, and even the Kuiper belt. It also shows that Sedna's orbit is still inside the Oort cloud.

Exploring Sedna's Orbit

Sedna's orbit is very unusual. It is shaped like a long, stretched-out oval. At its closest point to the Sun, called perihelion, Sedna is still very far away. At its farthest point, it travels almost to the inner edge of the Oort cloud. The Oort cloud is a huge, icy region far beyond the planets.

Because Sedna is so far away, it moves very slowly. This is why it takes thousands of years to complete one orbit.

Future Missions to Sedna

Currently, NASA does not have any plans to send a spacecraft to Sedna. However, scientists are talking about possible missions in the future. The best time to visit Sedna would be when it reaches its closest point to the Sun (perihelion) again. This would make the journey shorter and easier.

Images for kids

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  The orbit of Sedna compared to the orbits of outer Solar System objects. Pluto's orbit is purple, and Neptune's is blue.

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  How bright Sedna and two other sednoids appear over 10,000 years.

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  A diagram showing the orbits of Sedna, 2012 VP₁₁₃, and Leleākūhonua. The grid helps show the scale in astronomical units (AU).

See also

In Spanish: (90377) Sedna para niños