The first Jovian moons were discovered by

• Galileo

• Tycho

• Huygens

• Cassini

The Jovian moons Ganymede and Titan are

• larger than the Earth

• larger than Mercury but smaller than the Earth

• larger than the Moon but smaller than Mercury

• about the same size as Mars

The Jovian moons Io, Europa, Callisto and Triton are

• larger than Pluto but smaller than Mercury

• smaller than Pluto

• about the same size as Pluto

• larger than Pluto but smaller than the Moon

Which of the following is NOT a moon of Jupiter?

• Ganymede

• Callisto

• Titan

• Io

Which of the following is a moon of Neptune?

• Titan

• Triton

• Europa

• Ganymede

The fact that many of the larger Jovian moons orbit nearly in the equatorial plane of their host world, moving in the same direction as their planet's spin, suggest that they

• formed from a rotating disk of gas and dust like a miniature solar system

• spun out from the rapidly spinning host world as it formed

• formed elsewhere in the solar system and were later captured

• were formed from a giant impact between the host world and another body

Many of the smallest Jovian moons are most likely

• captured asteroids and comets

• captured objects from outside the solar system

• small clumps of gas left over from the formation of the host planet

• fragments of other moons

What is an indication that a planetary moon may have been captured?

• it revolves in retrograde direction, opposite to the direction of planetary spin

• it has a highly elliptical orbit

• it has an orbit which is inclined to the equator of the host planet

• all of these are indications

The largest Jovian moon that appears to have been captured is

• Titania, the moon of Uranus

• Io, the moon of Jupiter

• Triton, the moon of Neptune

• Titan, the moon of Saturn

Triton, the largest moon of Neptune was probably once

• a Kuiper Belt object

• a planet

• an asteroid

• a comet