Redshift survey

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/redshift-survey

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 the cosmological redshift calculation?z = (λobserved - λrest) / λrest, where λ is wavelength
2. What is the key observational technique?Spectroscopy to measure spectral line shifts for distance determination
3. How do scientists know how fast a galaxy is moving away?They measure the shift in the light's color, called redshift, and use a simple formula to calculate the speed and distance.
4. Why do scientists call the galaxy pattern a "cosmic web"?Because the galaxies and dark matter form long threads and huge empty spaces, like a web that stretches across the universe.

Cosmological Redshift: The stretching of light wavelengths due to the expansion of space itself, indicating distance and recessional velocity.
Baryon Acoustic Oscillations (BAO): Characteristic patterns in the distribution of matter imprinted by sound waves in the early universe, used as a standard ruler.
Intergalactic Medium (IGM): The diffuse gas and plasma that exists between galaxies, studied via absorption lines in quasar spectra.