Minimum and Maximum Distance of Planets to Earth
What’s the closest and farthest planet from Earth?
It is a common point of discussion that how vast is this universe we live in. Scientists are exploring all parts of space to provide an answer with scientific proof to back that. They have had no luck to date and concepts like Parallel universe are making things much more complex than ever. However, we can make a rough estimate of the vastness of our universe by knowing the distances between Earth and the other planets of our solar system.
These distances are inconsistent for all the planets including Earth as they are moving in their corresponding orbits. The distance between any two planets is minimum when they are on the same side of the Sun and form a line with it. Similarly, they are at a maximum distance when they are on different sides of the Sun and form a line. Another factor that determines this distance is the placement of the orbit of any particular planet. All the planets whose orbits lie closer to the Sun than the Earth’s orbit are closest to the Earth at the time of Inferior Conjunction. On the other hand, planets having a greater distance from the Sun are at a minimum distance from Earth during times of Superior Conjunction.
The units of measurement used for measuring average inter-planetary distances are called Astronomical Units (AU). One AU is equal to 149,598,000 kilometers. It is the distance between the Earth and the Sun of our solar system. The following explanation might stir some sensitive parts of your brain.
· Mercury
The minimum distance between these two planets is 77 million kilometers that can be observed at the time of inferior conjunction. It continues to increase till we reach superior conjunction. The inter-planetary distance is calculated to be 222 million kilometers during that phase. The average distance between them is 0.61 AU.
· Venus
The average distance between these planets is about 42 million kilometers. This is equal to 0.28 AU. The minimum gap is about 38 million kilometers while it can increase to 261 million kilometers in the worst case.
· Mars
The minimum distance between Earth and Mars is 55 million kilometers. Theoretically, they can come as close as 54.6 million kilometers but the smallest distance ever observed is 56 million kilometers. The mean distance from here to the red planet is about 225 million kilometers. On the scale of astronomical units, it is equal to 0.52 AU. These planets can go as far as 401 million kilometers.
· Jupiter
Jupiter takes 11.86 Earth years to complete one round of the sun. It was considered to be moving backward in the night sky up until the discovery of Johannes Kepler in which it was explained that the motion of planets around the central sun is not circular but, elliptical. The minimum distance between these two planets is 588 million kilometers that can be observed at the time of superior conjunction. It continues to increase till we reach inferior conjunction. The inter-planetary distance is calculated to be 968 million kilometers during that phase. The average distance between them is calculated to be 4.20 AU.
· Saturn
The Earth is at a distance of 1 AU from the sun. On the other hand, Saturn is more than 9.50 AU away from the sun. If we subtract these figures, the result will be 8.5 AU which is equal to 1300 million kilometers. But, as the orbits are elliptical, the inter-planetary distance will continue to vary. Therefore, the maximum distance between both these planets is about 1700 million kilometers while the minimum distance lies in the range of 1200 million kilometers.
· Uranus
When both these planets are found on the same side of the sun, the smallest distance between them is possible and it is expected to be about 2570 million kilometers. When they are on opposite sides, the maximum distance between them is determined and it is about 3150 million kilometers. Average distance is 18.54 AU.
· Neptune
Neptune is approximately 30 times away from the sun than the Earth. As a result, the maximum distance between these planets can go up to 4700 million kilometers while they can come as close as 4300 million kilometers. The average distance is measured to be 29.06 AU which is roughly equal to 4560 million kilometers.

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