Small Worlds, Big Science: Dwarf Planet Size Quiz

If the inner solar system ends at the asteroid belt and the outer begins at Jupiter, then the only dwarf planet inside the belt is Ceres.

If Charon is ~1,212 km and Pluto is ~2,376 km, then Charon is roughly 51% the size of Pluto. Since 51% is about half, the statement is true.

If an object has sufficient mass, its own gravity overcomes rigid body forces to reach hydrostatic equilibrium. If Ceres is round, then it has reached this state.

If we look at the locations of dwarf planets, four are in the Kuiper Belt and one is in the Asteroid Belt. If Ceres is the one in the Asteroid Belt, then Ceres is the answer.

If we rank them by diameter: Pluto (2376km) > Eris (2326km) > Haumea (1632km avg) > Makemake (1430km) > Ceres (940km), then sequence A is the most accurate.

If Pluto and Eris are compared, Pluto has a slightly larger diameter than Eris. If Pluto is the largest by diameter, then Pluto is the correct answer.

If Pluto is ~2,376 km and Makemake is ~1,430 km, then Makemake is approximately 60-65% the size of Pluto. If 2/3 is ~66%, then Makemake is the closest match.

If Earth's volume is much greater than Pluto's (Pluto is ~0.6% Earth's volume), then you would need roughly 170 Plutos to fill the space of one Earth.

If Ceres is in the Asteroid Belt and the others are beyond Neptune, then Pluto, Eris, Makemake, and Haumea are Kuiper Belt objects.

If the Moon's diameter is about 3,474 km and Pluto's diameter is about 2,376 km, then the Moon is larger. If the Moon is larger, then A is the correct choice.

If we list the diameters of all five dwarf planets, Ceres measures approximately 940 km. If all other recognized dwarf planets are larger than 1,000 km, then Ceres is the smallest.

If Haumea's long axis is ~1,920 km and Ceres' diameter is ~940 km, then Haumea's length exceeds Ceres' width. Therefore, the statement is true.

If a dwarf planet rotates once every 4 hours, then centrifugal force pulls it into an ellipsoid shape. If Haumea is that specific dwarf planet, then Haumea is the answer.

If Mercury has a diameter of 4,879 km and the largest dwarf planet (Pluto) has a diameter of 2,376 km, then Mercury is larger. If Mercury is larger, the statement is false.

If Earth's diameter is ~12,742 km and the sum of the five dwarf planet diameters is ~8,000 km, then the sum is less than Earth's total. Therefore, they are less than half of Earth's width combined.

If Eris is denser than Pluto, then it can have more mass despite being smaller in size. If Eris has about 25% more mass than Pluto, then the statement is true.

If a planet must orbit the sun, be round, and clear its path, then a dwarf planet is one that meets the first two but fails the third.

If Dawn reached Ceres in March 2015 and New Horizons reached Pluto in July 2015, then Ceres was visited first. Therefore, Ceres is the correct answer.

If Earth is 12,742 km and Ceres is 940 km, then 12,742 divided by 940 is roughly 13.5. If the ratio is roughly 1:13, then Ceres fits the description.

If scientific measurements from the New Horizons mission confirmed Pluto's size, then 2,376 km is the accepted value.