Question

What is the exact distance from Earth to Neptune?

Answer 1

Hint: There cannot be an exact distance between the celestial bodies that are revolving. The question is to find the exact distance from the earth to Neptune, so, firstly, we will know the diameters of the planets and the number of planets that lies between the earth and Neptune.

Complete answer:
There are a total of 8 planets. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Among these planets, Mercury is the smallest planet in our solar system and Jupiter is the biggest planet in our solar system.
The serial arrangement of the planets starting from the planet that is nearer the sun is given as follows.
Mercury – Venus – Earth – Mars – Jupiter – Saturn – Uranus – Neptune.
So, the planet earth is in the third position and the Neptune is in the eighth position. Thus, there are 4 planets in between the planets Earth and Neptune.
If we take into consideration the diameters of the planets to compute the distance between the planets Earth and Neptune, we get,
We have to add the diameters of Mars – Jupiter – Saturn – Uranus. Thus, we get,
$$\begin{array}{rl}& D_M+D_J+D_S+D_U=2(3,397+71,492+60,268+25,559)\\ & \Rightarrow D_M+D_J+D_S+D_U=2\times 160716\\ & \therefore D_M+D_J+D_S+D_U=321432km\end{array}$$
Thus, the distance from the planet earth to Neptune should be more than 321432 km.
When the planets earth and Neptune line up on the same side of the sun, then they are almost 4.3 billion km apart and when the planets line up on the opposite sides of the sun, they are almost 4.7 billion km apart.
$$\therefore$$Considering the planets line up on the same side of the sun, then they are almost 4.3 billion km apart.

Note:
The arrangement of the planets in their decreasing sizes is given as follows. Jupiter > Saturn > Uranus > Neptune > Earth > Venus > Mars > Mercury. By computing the number of planets present in between the planets whose distance we are asked to find, we almost get the distance nearer to the exact distance.