Which planet is closest to earth

Common sense would say the answer is either Mars or Venus, our next door neighbors. Of the two, Venus comes closer to the Earth than any other planet and its orbit is closest to ours. But as an article in Physics Today points out, over half the time Venus is not the nearest planet; Mercury is.

In fact, the scientists behind the article crunched the numbers and found that on average, Mercury is the closest planet not only to Earth but to every other planet in the solar system as well.

The scientists developed a simulation of our solar system featuring all of the planets moving in their orbits. They let the planets orbit for thousands of simulated years, all the while calculating the distance between any two of them. The smaller distance gives us the closest planet.

Can you see what the problem with this reasoning is? What we actually calculate this way is the minimal possible separation between the two planets, i. But here is the catch. Any two planets only stay close for a small part of their orbits. If you answered Venus to the question above, you probably had in mind that Venus can get closer to the Earth than any other Solar System planet. That is correct. No other planet ever gets quite as close to us.

But is Venus always the closest planet to the Earth? Absolutely NOT! At the maximum separation, that is when Venus is on the opposite side from the Sun than the Earth, Venus is a whooping million miles away. Sometimes, like today, for example, the closest planet to the Earth is Mars. The smallest possible distance between us and the Red Planet is In Mars will make its close approach to the Earth on October 6. On that day it will be Of all the planets in the Solar System, Mercury has the smallest orbit.

Some of the time, Venus is all the way on the opposite side of the Sun because the two planets move at different speeds. In the commentary, the researchers devised a new mathematical technique, called the point-circle method, to measure the distances between planets.

This method averages the distance between a bunch of points on each planet's orbit , thereby taking time into consideration. When measured that way, Mercury was closest to Earth most of the time.

Not only that, but Mercury was also the closest planet to Saturn, and Neptune, and all of the other planets.