Q 01/05

Where does Saturn rank in distance from the Sun?

A) Sixth

B) Fifth

C) Seventh

D) Fourth

Answer · why

A) Sixth

It is the second-largest planet, after Jupiter, and the farthest one easily seen with the naked eye.

Q 02/05

Saturn is the only planet in the Solar System with which property?

A) Less dense than water

B) No moons of its own

C) A solid rocky surface

D) No magnetic field at all

Answer · why

A) Less dense than water

Its average density is 0.69 g/cm3, about 30% less than water, so in principle it would float.

Q 03/05

Saturn's rings are made mainly of what?

A) Rock

B) Water ice

C) Dust

D) Frozen methane

Answer · why

B) Water ice

There is a little rocky debris and a peppering of about 7% amorphous carbon.

Q 04/05

Roughly how thick are Saturn's main rings on average?

A) About 20 metres

B) About 2,000 kilometres

C) About 20 kilometres

D) About 2 metres

Answer · why

A) About 20 metres

They stretch out over 120,000 km from the planet yet are thinner than many buildings are tall.

Q 05/05

Who first recognised Saturn's rings for what they were, in 1655?

A) Johannes Kepler

B) Galileo Galilei

C) Giovanni Cassini

D) Christiaan Huygens

Answer · why

D) Christiaan Huygens

Galileo in 1610 had taken the bulges for two moons flanking the planet.