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The Solar System Challenge
Planet counts changed in 2006, when the International Astronomical Union classed Pluto as a dwarf planet. This quiz uses that definition: eight planets, with Pluto named only as the object that is no longer on the list.
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“Largest” here means diameter, and “hottest surface” is not the same as “closest to the Sun.” Venus is the case that separates those two ideas. The asteroid belt question names the two planets it lies between.
Each explanation names the public reference checked on 6 October 2026. The quiz is for entertainment and does not compare your score with anyone else. It also does not ask you to guess how an average person would do. Read the wording with care. There is no time limit. Take the questions one at a time.
Updated 6 October 2026.
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