How big is 2004 DW?
So far, we are not sure. The size has not been accurately measured like the size of Quaoar has. However, we know the object’s distance very roughly as well as its brightness. Using this and our best guess at the object’s albedo (how light or dark the surface is) of 9%, the object is probably about 1600 km in diameter, larger than the 1250 km Quaoar. If subsequent measurements verify this size estimate, this would make 2004 DW the largest minor planet known, and larger than Pluto’s moon Charon, which is about 1300 km in diameter. This still doesn’t beat Pluto, which is about 2300 km in diameter.
