Universe Unit Review

Front

What is a light year?

Back

A light year is a unit of distance that represents how far light travels in one year, approximately 5.88 trillion miles (9.46 trillion kilometers).

Front

How long does it take for light from Proxima Centauri to reach Earth?

Back

Light from Proxima Centauri takes 4.3 years to reach Earth, meaning the star is 4.3 light years away.

Front

What is the phenomenon called when galaxies move away from us and a shift in the electromagnetic spectrum is observed?

Back

This phenomenon is called redshift.

Front

What information can the radiation from a star provide?

Back

The radiation from a star can provide information about its temperature, composition, distance, and motion.

Front

What happens to the perceived wavelength of a wave during blueshift?

Back

During blueshift, the perceived wavelength of the wave decreases.

Front

What is the relationship between redshift and the movement of galaxies?

Back

Redshift indicates that galaxies are moving away from us, which is evidence for the expansion of the universe.

Front

What does the term 'electromagnetic spectrum' refer to?

Back

The electromagnetic spectrum refers to the range of all types of electromagnetic radiation, including visible light, radio waves, X-rays, and gamma rays.

Front

What is the significance of a star's spectrum in astronomy?

Back

A star's spectrum can reveal its temperature, chemical composition, and motion relative to Earth.

Front

What is the Doppler effect in relation to light?

Back

The Doppler effect refers to the change in frequency or wavelength of light from a source moving relative to an observer, resulting in redshift or blueshift.

Front

How does distance affect the brightness of a star as seen from Earth?

Back

The brightness of a star decreases with distance; a star that is farther away will appear dimmer than a closer star.