# Closest planet to Earth is Mercury

(ORDO NEWS) — It will be forgiven if you think that our nearest planetary neighbor is Venus. In a sense, you are right – Venus is closer to Earth than any other planet in the solar system.

Likewise, its orbit is closer to ours than any other. However, in another sense you would be wrong. At least this argument is presented in an article published in Physics Today.

To identify our nearest neighbor, engineers partnering with NASA, the Los Alamos National Observatory, and the US Army Engineering Research Center built a computer model to calculate the Earth’s average proximity to the three closest planets (Mars, Venus, and Mercury) over a 10,000-year period.

Because of the way the planets align during their orbits, the model shows that Earth spends more time closer to Mercury than either Venus or Mars.

“In other words, Mercury is on average closer to Earth than Venus because it orbits the Sun more closely,” the authors explain.

Indeed, it is not just Earth. Further calculations show that all seven planets in the solar system spend most of their orbit closer to Mercury than any other planet. Sounds impossible? Here’s how they figured it out.

The results are based on a method called the dotted circle method (PCM) – essentially a mathematical equation that takes the orbits of two planets as circular, concentric and coplanar and calculates the average distance between the two planets as they orbit the sun.

“From PCM, we observed that the distance between two orbiting bodies is minimal when the inner orbit is minimal,” the authors explain.

“This observation leads to what we call the vortex-dirley consequence: for two bodies with roughly coplanar, concentric circular orbits, the average distance between the two bodies decreases as the radius of the inner orbit decreases.”

“It becomes clear that Mercury (average orbital radius 0.39 AU), and not Venus (average radius 0.72 AU), is the closest planet to Earth on average” (AU is an astronomical unit equal to the distance between the Earth and the Sun).

To test their hypothesis, they built a computer model that tracked the positions of all four planets over a 10,000-year period and calculated the average distance between them.

The results of this simulation differed from traditional calculations (determined by subtracting the average radius of the inner orbit from the average radius of the outer orbit) by a staggering 300 percent.

It turned out that the average distance between the Earth and Venus is 1.136 astronomical units (0.28 according to the “old method”). By comparison, the average distance between Earth and Mercury was 1.039 astronomical units (0.61 by the “old method”).

The hypothesis has not yet been presented in a peer-reviewed article and will no doubt be subjected to scrutiny by experts in the field.

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