The arrangement of the planets in the solar system, which move outward from the sun, has not changed.
Earth has Venus as the next planet in, toward the sun, and Mars is the next planet out from the sun. Of these two, Venus comes closer to Earth than Mars at their closest approaches. Therefore, it is still correct to say that Venus is closer to Earth than any other planet.
Confusion arises when we talk about the average distance between the planets.
Now, Mercury, which is closer to the Sun than Venus, orbits the Sun more quickly than our closest neighbors. Furthermore, Mercury’s farthest distance from Earth (when it’s on the opposite side of the Sun) is much less than Venus’ farthest.
These facts mean that if we average the distance between Earth and these two planets, Mercury is, on average, closer to Earth. It turns out that Venus is, on average, 1.14 astronomical units (AU) from Earth, but Mercury, on average, is only 1.04 AU from Earth. The AU is a unit of length equal to the average distance between the Earth and the Sun.
The latter analysis showed that for two bodies with concentric and circular orbits nearly on the same plane, the average distance between the two bodies decreases as the radius of the inner orbit decreases.
This seems counterintuitive. What it means is that Mercury is not only the closest planet to Earth, but also the closest neighbor, on average, to each of the other seven planets in the solar system!
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But the fact that Venus is approaching Earth remains unchanged.
Request: Conrad Owen, York
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