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How Sunlight Warms the Earth


Grade Range
Group Size
2-3 students
Active Time
70 minutes
Total Time
90 minutes+
Area of Science
Weather & Atmosphere
Key Concepts
Earth's surface, warm, cold, in the sun
Sabine De Brabandere, PhD, Science Buddies
Three cups filled with water, soil and rocks sit on a window sill in direct sunlight


Kindergarten students associate the sun with light and warmth. This lesson helps them expand this knowledge by getting their hands dirty! They will fill cups with soil, water and rocks and place them in the sun and shade for a while. By finding out how they can tell where a cup has been stored, they will learn how the sun affects Earth's surface.

In a follow-up lesson, Create Shade to Protect from the Sun, students figure out how to protect a territory from getting too hot in the sun.

Learning Objectives

NGSS Alignment

This lesson helps students prepare for these Next Generation Science Standards Performance Expectations:
This lesson focuses on these aspects of NGSS Three Dimensional Learning:

Science & Engineering Practices Disciplinary Core Ideas Crosscutting Concepts
Science & Engineering Practices Planning and Carrying Out Investigations. Make observations (firsthand or from media) to collect data that can be used to make comparisons.
Disciplinary Core Ideas PS3.B: Conservation of Energy and Energy Transfer Sunlight warms Earth's surface.
Crosscutting Concepts Cause and Effect. Events have causes that generate observable patterns.


Soil, gravel, a towel, plastic cups and a marker

Background Information for Teachers

This section contains a quick review for teachers of the science and concepts covered in this lesson.

The Sun is the main source of heat and light on Earth. Without it, we could not survive on our planet. The Sun is about 93 million miles (150 million kilometers) away, but because the Sun's surface is so hot (about 10000°F) and bright, we on Earth can still see the light it radiates. The Sun acts like a gigantic bonfire, sending light in all directions, including to Earth.

Photo from space of the Sun emerging from behind the horizon of the Earth
Figure 1. The Sun illuminates Earth.

The light radiated by the Sun carries energy. When this light reaches a surface, part of it gets absorbed and transformed into heat. That is why places in the sun feel warmer than places in the shade. Your kindergarten students know this from experience. On a cold day, they might prefer to play in the sun; on a hot day, they search for a cool spot in the shade. This lesson helps your students to explore what being in the sun does to the surfaces that cover our Earth. A follow-up lesson, Create Shade to Protect from the Sun, explores creative solutions to protect a surface from the effects of the Sun.

Earth's surface is covered with water (about 70%!), soil, rocks, snow, and ice, and a wealth of man-made materials like concrete. Note that when viewed from space, you could also say that plants (like trees and shrubs) cover the surface of the Earth. For the purposes of this project, we are concerned with the Earth's surface at ground level—so we consider larger plants and shrubs to be things that provide shade to other materials on Earth's surface.

When Earth's surfaces are exposed to the sun, they absorb some of the light and become warmer. In this lesson, your students will feel how soil, rocks, and water feel warmer after being in the sun. If you allow students to feel at different moments, they might notice that this warming effect does not happen instantly, but gradually; this process takes time. They might also notice that some materials warm less or less quickly than others.

Technical Note:
Two different materials at the same temperature can feel very different. A metal doorknob will feel colder than a wooden door, even if they are at the same temperature. This occurs because metal is a better conductor of heat, so it absorbs heat from your hand more quickly and thus, feels colder. For this reason, you cannot reliably compare the temperatures of two different materials (e.g. rocks and dirt) by feeling them with your hands. To make a comparison between two different materials, you need to measure their temperatures with a thermometer. Use an infrared thermometer if you want to add temperature measurements to this lesson.

Prep Work (10 minutes)

Engage (15 minutes)

Explore (45 minutes)

Reflect (10 minutes)


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Lesson Plan Variations

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