Question

When and where does a rainbow appear in the sky? List the phenomena of light in proper sequence which occurs during the formation of a rainbow. Why can a rainbow not be seen from the surface of the moon?

Answer 1

After rain, a rainbow forms in the sky when sunlight is present, appearing opposite the sun.

Rainbow formation involves the following sequence of light phenomena:

1. Refraction: Sunlight bends upon entering raindrops due to the slower speed of light in water compared to air. Different light wavelengths refract at varying angles.
2. Reflection: The refracted light then bounces off the inner surface of the raindrop.
3. Dispersion: During refraction and reflection, light splits into its constituent colors (spectrum) because each wavelength bends at a unique angle.
4. Second Refraction: The dispersed light exits the raindrop, undergoing a second refraction as it moves from water to air.

A rainbow is not visible from the lunar surface due to:

Rainbows depend on sunlight interacting with water droplets in an atmosphere. The moon lacks an atmosphere and, consequently, water droplets to refract and reflect sunlight, preventing rainbow formation on its surface.