Longer Days on Planet Earth

By M.P. Pellicer | Stranger Than Fiction Stories
In the last 1.4 billion years the moon has moved further from the earth, increasing the length of a day by six hours, thus days are 30% longer.

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The moon is the earth's natural satellite

The moon has been drifting slowly away from Earth at a rate of 1.5 inches per year, and the effect is longer days. The weakening pull of the planet's only natural satellite has resulted in a slower spin, and thus it takes longer for a complete 360° rotation to take place.

There was a time when a day on earth lasted only 18 hours. This was about 1.4 billion years ago.

Using astrochronology science has been able to reconstruct Earth and the solar system's past. Each planet influences other bodies around it including the speed they rotate on their axis. These variations are known as Milankovitch cycles.

The earth is tilted at 23.5 degrees pointing toward Polaris (North Star) as it travels around the sun. For those living in the Northern Hemisphere, which is more populated than the southern hemisphere, days are longer in the summer than in the winter.

There are only two times during the year when the Earth's axis is tilted neither toward nor away from the sun. This is when the length of time for the day and night are equal at all latitudes. These dates are known as Equinoxes.

The Summer Solstice is when the earth's tilt to/from the sun is at a maximum. It occurs when the sun is directly over the Tropic of Cancer at 23.5° latitude North and runs through Mexico, the Bahamas, Egypt, Saudi Arabia, India, and southern China. This is the longest day of the year.

The winter solstice is marked by the longest night and the shortest day. In the Northern Hemisphere, this is when the sun is directly over the Tropic of Capricorn, located at 23.5° south of the equator and runs through Australia, Chile, southern Brazil, and northern South Africa.

​At latitudes greater than 66.5 degrees (90 degrees minus 23.5 degrees, the tilt of the axis), the regions above the Arctic and Antarctic circles on our globe, days of constant darkness or light occur.

Mars' cycle is similar to Earth since it rotates on its axis every 24.6 hours. By contrast Venus turns on its axis every 243 Earth days. Think of daytime lasting about 8 months, and then nighttime for the same amount of time.

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