The Night Sky on Other Planets


Hello, astrophotographers.

In this week's investigation, we will put together all we know so far about how light travels and consider how that affects our sky on Earth. We will begin with the question of "What is light?" and "Why is the sky blue?" as we try to review the following standards...


  • MS-ESS1-1. Develop and use a model of the Earth-sun-moon system to describe the cyclic patterns of lunar phases, eclipses of the sun and moon, and seasons

    • [Clarification Statement: Examples of models can be physical, graphical, or conceptual.]

  • MS-ESS1-2. Develop and use a model to describe the role of gravity in the motions within galaxies and the solar system. 

  • MS-PS4-2.Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

  • MS-PS4-2B. The path that light travels can be traced as straight lines, except at surfaces between different transparent materials (e.g., air and water, air and glass) where the light path bends. Lenses and prisms are applications of this effect.

    • [Clarification Statement: A wave model of light is useful for explaining brightness, color, and the frequency-dependent bending of light at a surface between media (prisms). However, because light can travel through space, it cannot be a matter wave, like sound or water waves.]

Focus Questions to consider!

  • Why is the sky blue?
  • How does light interact with an atmosphere?
  • Why do solar or lunar eclipses occur?


As astrophotographers, we should be able to demonstrate mastery of light by anticipating what the night sky looks like on another planet. We should be able to take what we know about light, the phases of the moon, and our understanding of the Earth to make an argument (to what these faraway places look like) based on evidence.

So... what does the night sky look like on another planet?


Image result for exoplanet night sky



A. What is light?

Let's watch a short, but complex video about light. [Crashcourse Astronomy - Light]

As you watch, look out for the following vocabulary words:

  • Light
  • Waves
  • Energy
  • Visible Light
  • Electromagnetic Radiation
  • The Electromagnetic (EM) Spectrum

Questions to answer by the end of the video:

  1. How is light made?
  2. What is wavelength and what can it tell us about energy? What can wavelength tell us about color?
  3. What is spectroscopy?

B. Why is the sky blue?

Now that we know a bit more about why we can see,  let's take a look at why we see the way we do on our planet? Spoiler alert: It's because of light!

Take a short look into the Tyndall effect and consider what we just watched about Light. [UCR Physics: Why is the sky blue?]

Questions to answer by the end of the reading:

  • Why is the sky blue? Why is the sky red on Mars?

The short reading should have you making connections to how the presence of an atmosphere plays a huge role in how we experience day and night, as well as why the sky looks the way it does in certain times of the day. As you have these wonderings, you're going to want to explore a little more in order to be able to answer our INVESTIGATIVE QUESTION.

C. What are eclipses? 

Understanding eclipses and the phases of the moon will help us build a more complete understanding of why specific phenomena occur. [Crashcourse Astronomy - Eclipses]

Your objective from this video is to answer the following questions:

  1. Why do eclipses happen?
  2. What do eclipses tell us about how light behaves?
  3. Why does the moon turn red during a lunar eclipse? (Hint: this is connected to the Tyndal effect AND the EM spectrum!)

The next step is to review! Don't be afraid to revisit your resources.



Before moving on to our final mini-project, take the following quizzes to orient yourself with our standards. Remember, our main objective is to be able to apply our understanding of the Earth and light in order to make scientific arguments about how the sky would look like on another planet.

  1. Quiz on Lightwaves
  2. Quiz on the Earth, Moon, and Sun

Answers are at the bottom of each quiz. After each self-assessment, consider the following questions before moving on to the final task:

  • What evidence will help you support your understanding of exoplanets?
  • How do you rate your understanding of the interactions between light and planets?

Image result for exoplanet night sky

Wow! That's a lot of knowledge to take in!

To demonstrate mastery of LIGHT and the Earth, Moon, and Sun system - you, as an astrophotographer, are tasked with creating an image mock-up of the night sky on an exoplanet.

This image must:

You should also:

  • Prepare a 5-7 sentence reflection EXPLAINING your image.
  • Cite 2-3 valid resources (Wikipedia is a great place to look for resources but should NOT be your primary resource NOR be part of your works cited page).

You can create an image mock-up by:

  • Editing an existing image using an image editor.
  • Painting or creating a visual model and take a picture/scan to upload into a document.
  • Using a word processor to put your image and reflection into one file. (You may also put your image and reflection into one slide/drawing using the Google Suite).

Email your finished product to your teacher!


Credits go to:

Teacher Page

This Webquest was developed by Ann Libo-on - for curriculum reference go here. For ISTE coach portfolio, visit this site.

Use this Webquest for Earth Moon and Sun summative activity and to review Lightwaves. All content is aligned with NGSS and focuses on the skill of engaging in an argument using evidence.