AST MT1 - General Solar System

Lessons 1 and 2

1 AU is how many km?

150 million km

How long does light take to travel 1 AU?

Eight minutes

Define ‘“planet”

A body of significant size that orbits a star and does not produce its own light.

What is the scale of the universe?

Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Average distance between stars

3,386 km or from Toronto to British Columbia

Rate that light travels at

300,000 km/s

How many stars does each galaxy have?

Approximately 100 billion.

Define “differentiation”

The process where gravity separates a planet’s interior into layers of compositions and densities.

Define “geological activity”

The reshaping of surfaces as the result of a hot interior (larger planet = more heat = more evidence of this)

Define “Ecliptic Plane”

The plane that all planets (except dwarf planets) and the Sun orbit on.

Which planet is this:

• “No” atmosphere and no moons

• Highly cratered and rocky exterior

• Huge iron core

• Smallest planet

Mercury

Which planet is this:

• Thick CO2 atmosphere due to runaway greenhouse effect

• Many volcanoes

• No moons

• Slow and backwards rotation

• Similar size to Earth

Venus

Which planet is this:

• O2 and N2 atmosphere

• Many volcanoes

• Large moon

• Seasons caused by 23.4 degree tilt

Earth

Which planet is this:

• Thin CO2 atmosphere

• Evaporated ocean and polar ice

• Extinct volcanoes

• Two small moons

• Seasons caused by 25.2 degree tilt

Mars

Which planet is this:

• Thick, gaseous atmosphere surrounding liquid hydrogen

• Faint rings

• Many moons

• Largest planet

Jupiter

Which planet is this:

• Many moons

• Thin rings

• Similar structure to another planet with rings

Saturn

Which planet is this:

• Cold, small, and rocky core

• Thick H2/He atmosphere

• Many moons

• 98 degree rotational axis tilt

Uranus

Which planet is this:

• 28 degree rotational axis

• Structure similar to Uranus

• 2,100 km/h winds

Neptune

Describe the terrestrial planets

• Mercury, Venus, Earth, Mars

• Small and rocky

• Thin/no atmosphere

• Few moons

• Heavy elements

Describe the Jovian planets

• Jupiter, Saturn, Uranus, Neptune

• Large

• Gas and liquid

• Many moons

• Light elements

What is interesting about Jupiter’s moons?

• High ice content

• All orbit on the same plane (almost ecliptic)

What is interesting about Saturn’s moons?

• High ice content

• Orbit on the same plane (tilt of 27 degrees) and direction as the rings

• One is called “Titan”

What is interesting about Uranus’ moons?

• High ice content

• Orbit on the same plane (tilt of 97 degrees)

What is interesting about Neptune’s moons?

• Orbit is not the same plane or rotation (opposite direction and massive tilt)

• Surface is of frozen Nitrogen

• One is named Triton

Name two dwarf planets

Pluto and Ceres

Describe the asteroid belt

A region of space between the orbits of Mars and Jupiter where most of the asteroids in the Solar System are found.

Describe the Kuiper Belt

A collection of small, icy bodies beyond Neptune’s orbit, including many Dwarf planets.

Describe comets

Small, icy bodies from the outer solar system that emit trails when close to the Sun.