How big is the biggest asteroid? How bit is it compared to our moon?

1 Answer

Ceres is the largest asteroid in solar 975 x 975 x 905 Km in size..


Its Diameter is 28% that of Moon.enter image source here
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In 2006 the International Astronomical Union created a new category called a dwarf planet. Ceres got promoted to dwarf planet at the same time that Pluto was demoted to dwarf planet. So, Ceres is technically no longer an asteroid. This makes the largest asteroid Vesta.