Compare the sizes of Earth, its moon (Luna), Pluto, and three of the more recently discovered objects that are leading astronomers to debate the definition of a planet.
Original artwork by Windows to the Universe staff (Randy Russell) using images courtesy of NASA/JPL-Caltech/R. Hurt and NASA, ESA, and A. Feild (STScI).

Earth is much bigger than Pluto. Even Earth's moon, Luna, is bigger than Pluto. This picture also shows some other objects that might, or might not, be planets.
Original artwork by Windows to the Universe staff (Randy Russell) using images courtesy of NASA/JPL-Caltech/R. Hurt and NASA, ESA, and A. Feild (STScI).

Earth is much bigger than Pluto. Even Earth's moon, Luna, is bigger than Pluto. This picture shows some other objects. Do you think they are planets?
Original artwork by Windows to the Universe staff (Randy Russell) using images courtesy of NASA/JPL-Caltech/R. Hurt and NASA, ESA, and A. Feild (STScI).

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