Astronomy Solar System and Planetary Science

Question 1

What is the difference between a terrestrial planet and a gas giant?

Accepted Answer

Terrestrial planets have solid rocky surfaces (Mercury through Mars); gas giants are primarily hydrogen and helium (Jupiter, Saturn)

Answer

Terrestrial planets (Mercury, Venus, Earth, Mars) are small, dense, rocky worlds with solid surfaces. Gas giants (Jupiter, Saturn) are massive planets composed primarily of hydrogen and helium without a well-defined solid surface.

Question 2

What is the Kuiper Belt?

Accepted Answer

A region of icy bodies beyond Neptune's orbit extending to about 50 AU from the Sun

Answer

The Kuiper Belt is a disc-shaped region beyond Neptune (30-50 AU) containing millions of icy bodies, including dwarf planets like Pluto, Eris, and Makemake, remnants from solar system formation.

Question 3

What causes the seasons on Earth?

Accepted Answer

The 23.5° tilt of Earth's axis relative to its orbital plane, causing varying angles of sunlight throughout the year

Answer

Earth's axial tilt of 23.5° causes the Northern and Southern hemispheres to receive different amounts of direct sunlight throughout the year, creating seasons. Distance from the Sun plays a negligible role.

Question 4

What is an exoplanet and how are they detected?

Accepted Answer

A planet orbiting a star other than our Sun; detected through transit method, radial velocity, and direct imaging

Answer

Exoplanets orbit other stars. The transit method detects brightness dips as planets cross their star, radial velocity measures stellar wobble from gravitational tug, and direct imaging captures the planet's own light.

Question 5

What is a comet and what creates its tail?

Accepted Answer

An icy body that develops a visible atmosphere and tail when heated by the Sun, with the tail always pointing away from the Sun

Answer

Comets are icy bodies from the outer solar system. As they approach the Sun, solar radiation and wind vaporize surface ice, creating a coma (atmosphere) and two tails: a dust tail and an ion tail, both pointing away from the Sun.

Astronomy Practice Test

Astronomy Practice Test

Astronomy Solar System and Planetary Science