It’s our constant companion, and influences life on Earth in ways big and small
The moon is more than a bright, beautiful orb in the night sky. Our nearest neighbor also plays a big part in making the Earth a good place to live. Located an average of only 384,400 kilometers (238,855 miles) away, it’s got enough gravity to help stabilize the Earth on its axis. That makes our planet’s climate more stable than it would be otherwise. The moon’s gravity also pulls the oceans back and forth, producing tides.
As the moon orbits the Earth, it passes through different phases. They are the result of sunlight reflecting off the moon, and where the moon is in relation to the Earth. During a full moon, we see one entire half of the moon lit by the sun because the Earth is between the moon and the sun. During the new moon, none of the moon is visible and the sky is exceptionally dark. That’s because the moon is between the Earth and the sun, and only the dark side of the moon faces our planet.
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The moon cycles through all its phases once every 27 days. This is also the amount of time it takes to go around the Earth. As a result, the same side of the moon always faces the Earth. The far side of the moon was a mystery until people developed spacecraft. Now that far side is a bit less of an unknown. China has even landed a spacecraft on this far side of the moon, to learn more about it.
The moon’s light and its effect on the tides are important to animals here on Earth. Some animals time their breeding with the tides. Others change their feeding to stay safe from lions when the moon is dark. And deep in the Arctic night, the moon can provide some illusive illumination for living things.