Astronomy college course/Galilean moons of Jupiter/questions/Original version of this quiz

Galilean moons of Jupiter version A

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1 How does the density of a Galilean moon depend on its distance from Jupiter?

	all the moons have nearly the same density
	the more dense moon is closer to Jupiter (always)
	the density of the moons is unknown
	the less dense moon is closer to Jupiter (always)
	the most dense moon is neither the closest nor the most distant

2 How does the mass of a Galilean moon depend on its distance from the central body?

	the less massive moon is closer to Jupiter (always)
	the mass of the moons is unknown
	the most massive moon is neither the closest nor the most distant
	the more massive moon is closer to Jupiter (always)
	all the moons have nearly the same mass

3 Does Jupiter's moon Io have craters?

	no, the surface is too new
	yes, from impacts
	yes, from volcanoes
	no, the surface is too old
	yes, about half from impacts and the others from volcanoes

4 The mechanism that heats the cores of the Galilean moons is

	radiation from the Sun and from Jupiter
	tides from Jupiter
	radioactive decay of heavy elements
	tides from the other moons and Jupiter
	radiation from the Sun

5 Immediately after publication of Newton's laws of physics (Principia), it was possible to "calculate" the mass of Jupiter. What important caveat applied to this calculation?

	The different moons yielded slightly different values for the mass of Jupiter.
	The different moons yielded vastly different values for the mass of Jupiter.
	Only the mass of Jupiter relative to that of the Sun could be determined.
	tides from the other moons and Jupiter.
	They needed to wait over a decade for Jupiter to make approximately one revolution around the Sun.

6 Ganymede, Europa, and Io have ratios in __________ that are 1:2:4.

	orbital period
	Argon isotope abundance
	Two other answers are correct (making this the only true answer).
	density
	rotational period

7 Which of Jupiter's moons has an anhydrous core?

	Europa
	Ganymede
	Two other answers are correct (making this the only true answer).
	Io
	Ganymede