A scientific team just demonstrated a shocking new reality: Mercury, not Venus, is the closest planet to Earth on average.
The researchers presented their results this week in an article in the magazine Physics Today. The scientists explain that their methods of calculating which planet is “the closest” oversimplifies the matter. But that’s not all.
“Further, Mercury is the closest neighbor, on average, to each of the other seven planets in the solar system,” they write.
The present misconceptions about how close planets are to one another comes from the way we usually estimate the distances to other planets. Usually, we calculate the average distance from the planet to the Sun. The Earth’s average distance is 1 astronomical unit (AU), while Venus’ is around 0.72 AU. So if you subtract one from the other, you calculate the average distance from Earth to Venus as 0.28 AU, the smallest distance for any pair of planets.
But there were three researchers who realized that this isn’t an accurate way to calculate the distances to planets. After all, Earth spends just as much time on the opposite side of its orbit from Venus, placing it 1.72 AU away. Therefore one must instead average the distance between every point along one planet’s orbit and every point along the other planet’s orbit. The team of researchers ran a simulation based on two assumptions: that the planets’ orbits were approximately circular, and that their orbits weren’t at an angle relative to one another.
Here is a way of looking at this research: If you were getting seats to a football game, you would like to have them near the 50 yard line rather than one of the end zones in order to see the most action, even if you’d occasionally be much closer to the players from the end zone.
The team found that Mercury was the planet closest to the Earth for the most time, on average—and to every other Solar System planet.