8 Quaoar Facts | Interesting Facts about Quaoar

Where do we start with facts about Quaoar, the KBO that gathered so much attention when it was found? With so many new discoveries over the previous decades, it can be easy to forget about Quaoar.

Quaoar (pronounced QUAY-OAR) was found back in 2002, which is actually before we discovered most of the dwarf planets that we know today. It is one of the larger objects in the Kuiper belt, and its diameter is roughly half as much as Pluto.

One of the most commonly wondered things about Quaoar is why it isn’t classified as a dwarf planet. This is mainly because of the size of Quaoar – it’s actually bigger than Ceres, which is classified as a dwarf planet!

If we actually look at the diameter of Quaoar here, we can see that it that it is similar in diameter to many of the other dwarf planets, as well as Charon, which is one of Pluto’s moons. It’s worth noting that Charon cannot be a dwarf planet, because it orbits Pluto, which defies the criteria needed to be a dwarf planet. Ceres is has a diameter of 946km, so we can clearly see that Quaoar has the size to be classified as a dwarf planet.

Quaoar Facts

  1. Quaoar has only one moon, called Weywot. it orbits around Quaoar at an approximate 9000 mile distance.
  2. It’s thought that Weywot was created by a previous collision between Quaoar and another much larger object in the Kuiper belt. Quaoar itself might have been at least twice the size it is now before this collision.
  3. Although it definitely does count as a moon, Weywot is around 1/2000th the size of Quaoar.
  4. Quaoar takes its name from the Native American people of California, the Tongva. Weywot was Tongva’s son, which is why they named Quaoar’s moon as such.
  5. It was named this because the people who led the team responsible for finding Quaoar, Chadwick A Trujillo and Michael E Brown, found it whilst at Caltech University in California.
  6. Until astronomers named Quaoar, it was known as object X, because of its large size (Planet X is the name given to a hypothetical planet beyond Neptune).
  7. It takes Quaoar just under 289 years to complete one full orbit of the Sun. This seems like a long time, but when compared to object Sedna that’s further out from the Sun that takes more than 11,000 years to complete a full orbit, it doesn’t seem so long!
  8. A full day on Quaoar is equal to 17.68 Earth hours – this is how long it takes to complete one full rotation.
  9. The temperature on Quaoar is estimated to be -220 degrees, which is common for objects that have such a great distance from the Sun.


All in all, this is all we know about Quaoar so far. It’s essentially a dwarf planet in everything but name only, however since we have known about it since 2002, it is very surprising that it hasn’t been catalogued as a dwarf planet just yet. It’s size and spherical nature make it the perfect candidate to be one, so only time will tell whether Quaoar is added to the growing list of dwarf planets.