Beyond Our Solar System

How is Pluto different from Planet X?

• Planet X was never discovered; Pluto was

• Planet X is a gas giant; Pluto is a dwarf planet

• Planet X has several moons; Pluto has no moons

• Planet X contains single-celled life forms; Pluto does not

Why is Pluto no longer considered a planet?

• Its orbit is too irregular

• Its orbit is too far away from the sun

• It isn't large enough

• It orbits Neptune, not the sun

Place the following in order, from closest to furthest away:

A) The scattered disc;

B) The Kuiper Belt;

C) The Oort cloud

• A, B, C

• C, B, A

• B, A, C

• C, A, B

What can you infer about the Kuiper Belt from the objects that orbit within it?

• It's very small

• It's very cold

• It's very dense

• It's very close to Neptune

How is Orcus different from Charon?

• Orcus orbits the sun; Charon orbits Pluto

• Orcus is a dwarf planet; Charon is a Kuiper Belt object

• Orcus is a comet; Charon is a trans-Neptunian object

• Orcus is very large; Charon is very small

Place the following objects in order, according to size:

A) Earth;

B) Pluto;

C) Eris

• A, C, B

• B, A, C

• C, A, B

• A, B, C

Which of the following objects most likely originated in the Oort Cloud?

• Eris

• Pluto

• Comet Hale-Bopp

• Varuna

What is the difference between the termination shock and the heliopause?

• The termination shock slows the solar wind and the heliopause stops it

• The heliopause slows the solar wind and the termination shock stops it

• Sunlight is not visible from the heliopause; it is visible from the termination shock

• Sunlight is not visible from the termination shock; it is visible from the heliopause

What do the Voyager and Pioneer probes have in common?

• They've both passed the heliopause

• They were all launched during the 1980s

• They've all been very easy to track

• They're all unmanned spacecraft

If you had a spaceship that could travel at the speed of light, how long would it take you to reach the Oort cloud?

• About a year

• About six months

• About a month

• About a week