Unit 1.2 Practice

Front

What is a nebula?

Back

A nebula is an area in the universe characterized by a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette.

Front

What unit of measurement is used to measure distances within our solar system?

Back

Astronomical units are used to measure distances within our solar system.

Front

What is the most appropriate unit of measurement to express the distance between the Milky Way galaxy and the Andromeda galaxy?

Back

Light-year is the most appropriate unit of measurement for such vast distances.

Front

What happens to a comet when it gets close to the Sun?

Back

When a comet gets close to the Sun, its frozen material begins to melt and forms a trail of dust, rock, and gas behind it.

Front

What type of wave has the shortest wavelength and highest frequency?

Back

Gamma rays are the type of wave with the shortest wavelength and highest frequency, and they are extremely harmful.

Front

Define a galaxy.

Back

A galaxy is a massive system that consists of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity.

Front

What is the difference between a meteoroid, meteor, and meteorite?

Back

A meteoroid is a small rocky or metallic body in outer space; a meteor is the flash of light produced when a meteoroid enters the Earth's atmosphere; a meteorite is a meteoroid that survives its passage through the atmosphere and lands on Earth.

Front

What is the significance of light-years in astronomy?

Back

Light-years measure the distance that light travels in one year, used to express astronomical distances.

Front

What is the composition of a comet?

Back

A comet is composed of ice, dust, and rocky material.

Front

What is the role of gravity in the formation of galaxies?

Back

Gravity pulls together gas and dust to form stars and galaxies, creating the structure of the universe.