Twilight

High school (ages 12+)
Environment & Earth

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/twilight

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 types of twilight?Civil (0-6°), Nautical (6-12°), and Astronomical (12-18°)
2. What is the primary scattering mechanism?Rayleigh scattering by atmospheric molecules (N2, O2)
3. What is twilight and why does the sky look blue at that time?Twilight is the time just before night or after morning when the sun is below the horizon. The sky looks blue because tiny air molecules scatter blue light more than red light. This is called Rayleigh scattering.
4. How many kinds of twilight are there and what does each mean?There are three kinds: Civil (0-6° below), Nautical (6-12°), and Astronomical (12-18°). Civil twilight has enough light for most outdoor activities. Nautical and astronomical twilight are darker and are used for navigation and astronomy.

Diffuse Sky Radiation: Sunlight scattered by the atmosphere, illuminating the sky and ground when the sun is below the horizon.
Rayleigh Scattering: The scattering of light by particles much smaller than the wavelength of the light, causing shorter wavelengths (blue) to scatter more.
Liminal Space: A transitional or in-between state or place, often associated with periods like twilight.