This is something I have glossed over previously on this blog, but I think it’s worth revisiting as the perspective it brings tends to fade after time.
The Solar System is vast beyond our imagination. Humanity evolved to calculate and estimate relatively small distances. Nothing beyond the horizon because when we were a young species that was as far as we could see.
We now have technology that allows us to measure and estimate the distances between continents, countries and even from one point of the Earth to another.
The difference between these distances and the distances between celestial bodies (apart from orders of magnitude) is the fact that we can travel these distances. We know that when you live in Australia it takes you about 24 hours to get to London. That’s a distance represented in time, and we can work with that. It’s a long way but it isn’t incomprehensible.
The Solar System is different.
To make the numbers small enough that they aren’t mind bogglingly huge, we have to use different units known as light minutes. Or in other words, the distance light travels in one minute on Earth.
For instance, the Earth is roughly eight light minutes away from the Sun. The speed of light is 300 000 000 m/s. Times that by 60, and then by 8, and you have the distance to the Sun, roughly 144 000 000 kilometres (depending on where Earth is in its orbit, as the orbit is elliptical the distance changes over time).
That is a distance that dwarfs any on Earth. The distance from the North to the South pole is 20 000 kilometres.
The scale of the Solar System is huge.
Mars, the planet that humanity has focused on primarily over the past fifty years of space exploration, is at its closest point to Earth, 54.6 million kilometres away. And that is considered close when you are talking on a Solar System scale.
And for another reference point for you, Jupiter is 880 million kilometres away from Earth.
But all of these are numbers. Numbers that are too big to truly appreciate because we didn’t evolve the capacity to understand them when considering distance.
This might help.
The above is the single best representation of distance of the Solar System that I have found to date.
I hope it made you feel small, and I hope it made you appreciate how lucky we are to exist in such a vast expanse of nothingness.