Celestial Bodies and the Solar System

Define the following and give an example of the body in question: Star.

• A celestial body made of gases emitting light and heat

• A geometric shape with five points

• A symbol used in typography

• A famous celebrity

Define the following and give an example of the body in question: Planet.

• A celestial body orbiting a star, large enough to be rounded by its own gravity but not to cause thermonuclear fusion, like Earth.

• A natural satellite orbiting a planet, like the Moon.

• A small solar system body composed mainly of rock and metal, like an asteroid.

• A region of space having a gravitational field so intense that no matter or radiation can escape, like a black hole.

Define the following and give an example of the body in question: Moon.

• A celestial body that orbits a planet

• The natural satellite of Earth

• A star in the solar system

• A type of asteroid

Define the following and give an example of the body in question: Asteroid.

• A small rocky body orbiting the sun, e.g., Ceres

• A large gaseous planet, e.g., Jupiter

• A natural satellite of Earth, e.g., Moon

• A bright streak of light in the sky, e.g., Comet

Define the following and give an example of the body in question: Comet.

• A comet is a small celestial body that orbits the sun, primarily made of ice and dust, e.g., Halley's Comet.

• A comet is a large asteroid located between Mars and Jupiter, e.g., Ceres.

• A comet is a natural satellite of Earth, e.g., Moon.

• A comet is a bright star that remains fixed in the sky, e.g., Polaris.

Define the following and give an example of the body in question: Meteoroid.

• A meteoroid is a small rocky or metallic body in outer space, such as 3200 Phaethon.

• A meteoroid is a bright streak of light in the sky, such as Halley's Comet.

• A meteoroid is a celestial body that orbits the Earth, such as the Moon.

• A meteoroid is a small body of ice and dust that releases gas, such as Comet Hale-Bopp.

How old is the Solar System?

• 4.6 billion years

• 3.8 billion years

• 5.2 billion years

• 2.5 billion years

How has the age of the Solar System been determined?

• By studying the oldest rocks on Earth

• By radiometric dating of meteorites

• By observing the motion of galaxies

• By measuring the temperature of the Sun

What is an accretion disc?

• A structure formed by diffused material in orbital motion around a central body

• A type of astronomical telescope

• A region in space where gravity pulls so much that even light cannot get out

• A theory explaining the expansion of the universe

What did the accretion disc contain?

• Gas and dust

• Planets and stars

• Water and ice

• Rocks and minerals