The Similarities and Differences Between the Sun and Moon

Updated April 17, 2017

The sun and the moon are probably the two most prominent features of Earth's sky. They affect our daily life in significant ways, but are very different in their characteristics and effects on the solar system and our planet. Both of these bodies have been the subjects of extensive scientific research, as well as myths and tales across the ages.

Measurements of Time

Both the sun and the moon serve as bases for our systems of time measurement. The moon is the Earth's only natural satellite and is the basis of the month on our modern calendar. The moon takes 27.3 days to fully rotate around the earth. The sun, around which the Earth orbits, is the basis of the calendar year and day. The sun itself rotates within a period of 27 days.


The moon and sun are both bright round objects in our sky, but they are very different. The sun is a star, while the moon is a large mass of rock and dirt. According to most theories, the sun formed from the solar nebula, a giant mass of cloud and dust that collapsed because of its gravity. When it did, the material pulled into the centre formed the sun. When the Earth was born, it didn't have a moon. The moon was created when a large planet collided with the Earth. The resulting particle cloud rose and eventually condensed into the moon.

Make-up and Light Emission

The moon's surface is made of rocks and dirt. Under the crust is a mantle and small core, similar to what we find on Earth. The sun, like most stars, is a mass of gases. In the sun's case, this is mostly hydrogen, with small amounts of oxygen, carbon, nitrogen and several other elements. Both bodies appear to emit light, at least to the human eye. However, the sun produces its own energy, and therefore its own light. The moon has no light of its own, but reflects the light of the sun.

Effects on Earth

The sun is the source of light for the Earth, and is the reason that life exists on our planet. It causes plants to grow, it heats our planet, it provides us energy through solar panels and causes sun burns. The moon affects our tides because its gravitational attraction is stronger on the side of the Earth nearer to the moon. This attraction causes the "bulges" in the oceans that we see when looking at a photo of the Earth. Because the Earth rotates faster than the moon does, these bulges move around, creating the world's tides.


The climates of both bodies are extreme. The moon has no atmosphere and is heated by the sun, meaning the temperature of the "light" side reaches 117 degrees Celsius. The dark side, completely unheated, cools to -133 degrees C. The sun's temperature is even hotter, with the photosphere (the light-emitting zone) ranging in temperature from 7,460 to 0-11.667 degrees Celsius. The other layers of the sun's atmosphere are even hotter, with the corona reaching 900,000 degrees

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About the Author

Gwendolen Akard started writing professionally in 2004 for her high-school newspaper and hasn't stopped since. She began writing for various websites in 2008, focusing on fitness and music. Akard is pursuing bachelor's degrees in philosophy and music at Tufts University.