Red shift

High school (ages 12+)
Space & Astronomy

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/red-shift

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is red shift and why does it happen?Red shift is when light from faraway stars or galaxies stretches to longer, redder wavelengths because the space between us and them is expanding. It looks like a rubber band being pulled.
2. Why do most galaxies show a red shift?Most galaxies are moving away from us, so their light is stretched. This was first seen by astronomers like Vesto Slipher and later confirmed by Edwin Hubble.

Cosmological Red Shift: The lengthening of light wavelengths caused by the expansion of the universe itself, stretching spacetime.
Hubble's Law: The empirical relationship stating that the recessional velocity of galaxies is directly proportional to their distance from Earth.
Spectral Lines: Specific wavelengths of light absorbed or emitted by atoms, used as 'fingerprints' to identify elements and measure red shift.