Question 2: The most common dividing line on what is considered a moon rests upon whether the ________ is below the surface of the larger body, though this is somewhat arbitrary, as it relies on distance as well as relative mass.
Question 5: Of the inner planets, Mercury and Venus have no moons at all; Earth has one large moon, known as the Moon; and ________ has two tiny moons, Phobos and Deimos.
Question 6: Galileo chose to refer to his discoveries as Planetæ ("________"), but later discoverers chose other terms to distinguish them from the objects they orbited.
Question 7: Enceladus and Triton both have active features resembling ________, although in the case of Triton solar heating appears to provide the energy.