Posted on Tuesday 8 October 2002

Frequently Asked Questions About Quaoar

What is Quaoar?

Quaoar is a newly discovered Kuiper Belt object, found in June 2002 by Chad Trujillo and Mike Brown at Caltech in Pasadena. It's the largest Kuiper Belt object currently known, half the size of Pluto, and 1.6 billion kilometers (1 billion miles) further away than Pluto.

How big is Quaoar?

Quaoar is about 1250 km in diameter, roughly the size of Pluto's moon Charon. Nothing larger has been found in our solar system since Pluto was discovered in 1930. It's huge, in fact, if you took the 50,000 numbered asteroids and put them together, it would be smaller than Quaoar.

Here's a picture of Quaoar compared to some other Solar System objects, courtesy the Hubble Space Telescope graphic designers.



How was Quaoar found?

First of all, we are looking for objects like Quaoar because we think there may be a lot of objects like it that are undiscovered, and maybe even objects bigger than Pluto. We spent about 7 months looking for it with a semi-automated telescope, the Oschin Telescope at Palomar, California. It has a mirror diameter of 48 inches (1.2 meters), which is large compared to amateur telescopes (typically ranging from 0.1 - 0.3 meters in diameter), but small compared to most professional telescopes (1 - 10 meters in diameter). Although the mirror isn't very big, the Oschin Telescope has a huge field of view for its size, about 3 square degrees. That's about the same amount of sky area as 12 moons in each picture.