ScienceGrade 3

What Counts as Light Energy? Everyday Examples for Kids

Light energy is energy you can see, and it lets your eyes notice things

Learning Objective

Students will be able to tell light SOURCES (things that make their own light, like the Sun or a firefly) apart from REFLECTORS (things that only bounce light that already exists, like a mirror or the Moon), and explain that the Moon shines by reflecting sunlight rather than glowing on its own.

What You'll Learn

A light SOURCE makes its own light (the Sun, a candle flame, a lightbulb, a firefly)
A REFLECTOR only bounces light that already exists; it makes none of its own (a mirror, a bike
The Moon does not glow on its own — it reflects sunlight, and stops "glowing" the instant no
Light from the Sun takes about 8 minutes to reach Earth

Words to Know

Light energy: Energy you can see, that lets your eyes notice things; The Sun sends light energy all the way to Earth
Source: A thing that makes its OWN light; A candle flame is a light source
Reflect: When light bounces OFF something instead of being made by it; A mirror reflects your flashlight beam
Bioluminescence: When a living thing makes its own light using a chemical reaction inside its body; A firefly glows using bioluminescence

Check What You Learned

Quick Quiz

1 / 4

Which of these makes its OWN light?

Fun Facts

Sunlight takes about 8 minutes and 20 seconds to travel from the Sun to Earth
Source: NASA
The Moon does not make its own light — it reflects sunlight, and it only reflects about 12% of the sunlight that hits it, roughly as dark as a piece of asphalt
Source: NASA Solar System Exploration, lunar albedo data
Fireflies make their own light through a chemical reaction inside their bodies called bioluminescence, and almost none of that light is wasted as heat
Source: Smithsonian's National Museum of Natural History
Light travels about 186,000 miles (300,000 km) every second — fast enough to circle Earth about 7.5 times in one second
Source: NASA