The Solar System, how big is it really?
We can often see drawings of our planetary system in textbooks, but what is not shown are the true dimensions. That makes sense considering the vastness, but let’s try to get a clearer image of that.
So, our planetary system is mostly a huge empty space. Compared to the distances that separate them, the planets are so small that it is almost impossible to get a true picture of that relationship.
If we try to draw that up, we will have to use a large scale. Let’s assume that one millimeter in the drawing is equal to 20,000 kilometers, which is the distance from one pole to the other on Earth.
In the center, as has become normal since Copernicus, will be the Sun. It will be the size of an orange and have a diameter of 7 cm.
At a distance of 3 meters is the first planet of the system, Mercury. It is a single purple bead barely 1/4 mm in size and rotates counterclockwise around the Sun.
At 2.5 m from Mercury, that means at 5.4 m from the Sun, there is the next planet of the system, which is Venus. Its size is only 2/3 mm. At 2 m from Venus is our Earth, slightly larger than Venus – 0.64 mm.
So, let’s imagine an orange in a school classroom and a blue-green grain the size of a poppy in the corner of the classroom 7.5 meters away from it.
Around that grain, at a distance of 2 cm, revolves an almost invisible dot with a diameter of 1/5 millimeter – it represents our companion, the Moon. This is what represents the Sun and our planet Earth in space.
The last, so-called inner planet, is Mars. It is represented by one tiny ball of size 1/3 mm. Even with an ordinary microscope, we would not be able to see the satellites of Mars, Phobos and Deimos, in orbits 0.9 and 2.4 mm away from it. Their size is equal to the size of some bacteria.
After Mars, there is a large empty space. Admittedly, it is not so empty, because approximately 14 meters from Mars and 25 meters from the Sun, we encounter the asteroid belt.
At a distance of 27.5 meters from Mars, and at a full 39 meters from the orange that represented the Sun, there is the highest among the planets – Jupiter. Since its diameter is 11 times larger than the Earth’s, this means that 1,300 Earth globes can fit into its volume.
That’s why it is represented by a ball the size of a pea of 7 mm. Around it, one can see its largest satellites, which were discovered by Galileo in 1610. Then comes Europa and the largest, Ganymede, which is 1/4 mm in size and is half a decimeter from Jupiter.
It means that the entire Jupiter system would have a diameter of almost 5 meters.
That is a lot if compared to the Earth-Moon system with a diameter of almost 4 centimeters – nerdy trivia worth knowing!
By the way, did you hear that right here, at OSR you can name a star? Yes, real stars up in the sky! How brilliant is that?
Go ahead, pinch the orange. If you dare!