KidZone Science
Colors of the Sky: Sunrise and Sunset

The Daily Art of the Sky

• Sunrise and sunset are like daily art shows in the sky, displaying vibrant colors that differ from the usual blue. These moments offer a deeper look into the interaction between sunlight and the Earth's atmosphere.

The Angle of the Sun

• During sunrise and sunset, the sun is near the horizon, and its light has to travel through more of the Earth's atmosphere to reach us. This increased distance means the light encounters more air molecules and particles, which affects the colors we see.

Optical Path and Atmospheric Thickness

• The optical path is the route light takes through the atmosphere. At sunrise and sunset, this path is much longer compared to when the sun is overhead. The atmosphere acts like a filter, scattering and absorbing different wavelengths of light.
• As the sunlight travels through this thicker layer of atmosphere, most of the shorter blue and violet wavelengths are scattered out of the line of sight, leaving the longer wavelengths like red, orange, and yellow to reach our eyes.

The Role of Atmospheric Conditions

• The colors we see at dawn and dusk can be intensified by atmospheric conditions such as humidity, dust, and pollution. These particles can scatter light in a way that enhances the reds and oranges, making sunrises and sunsets even more spectacular.

Science Behind the Colors

• The reds and oranges seen during sunrise and sunset are due to Rayleigh scattering, but with a twist. Since the sunlight's path through the atmosphere is longer, more of the blue light is scattered away from our line of sight, allowing the warmer colors to dominate.

Interactive Activity: Sunset in a Glass

• Students can create their own "sunset" using a glass of water mixed with a few drops of milk (to simulate atmospheric particles) and a flashlight. By shining the flashlight through the side of the glass at different angles, they can observe how the color changes, simulating the effect of the sun's angle at sunrise and sunset.

This section brings the fascinating science behind the changing colors of the sky at dawn and dusk to life. By exploring the impact of the sun's angle and atmospheric conditions, students gain a deeper appreciation for these daily natural phenomena and the intricate science that creates them. The interactive activity provides a hands-on way to visualize these concepts.