How big is the solar system?

It is really hard to picture how big the Solar System is because of the huge distances and the massive difference in the size of the Solar System bodies. For example the Sun is huge, it’s 109 times as big as the diameter of the Earth at 1,391,000 kilometres and it’s 333,100 times heavier than the Earth. So imagine you are standing in an open field with a beach ball about 1 metre in diameter on your head – that’s the Sun! Now imagine the direction you are facing is 12 o’clock. What we’ll visualise now is what the Solar System would look like today based on the current positions of the planets relative to each other in real time. The planets that we will talk about are all pretty much on the ground in the fields around you (because technically they are roughly in the same plane – the plane of the Solar System, not the plane flying past).

 

At 6 o’clock from your position at about 33 metres away (one third the length of a rugby field) is a small ball bearing about 3.5mm in diameter, that’s Mercury. With a good throwing arm you can throw a tennis ball that distance. The small ball bearing would take 59 days to whizz around your beach ball so I hope you have a good book to read.

At 1 o’clock at 78 metres away is a marble sized object, that’s Venus. That’s just over three quarters the length of a rugby field, and you might see a marble at that distance. It’s 243 days for Venus to do one rotation of your beach ball.

Earth is another marble-sized object at 6 o’clock behind Mercury at 108 metres, just over the length of rugby field away. Usain Bolt can run that distance in just over 9 seconds (I take about 15 seconds and can’t walk for a week). Obviously it’ll take a year for the Earth to go around the beach ball.

Next up at just after 2 o’clock is Mars, it’s about half the size of a marble. Mars is 176 metres away. It would be really hard to see a half sized marble from that distance, you might need a binoculars. Mars takes 687 days to go around the sun and since we’re not scaling for time in this example then that’s how long it’ll take to go around your beach ball.

Now we’re in for some big distances, Jupiter would be about the size of a tennis ball and about half way between 1 o’clock and 2 o’clock. It’s a long way away though, it’s just over half a kilometre away at 586 metres. I couldn’t see a tennis ball at half a kilometre. That tennis ball is going to take 11.86 years to go around the beach ball.

Saturn is nearly at the 12 o’clock position (remember you’re standing with a 1 metre in diameter beach ball on you head which represents the sun), it’s a smaller tennis ball than Jupiter and it’s a whooping 1km away. That would take me about 6 minutes to run, and I’d be ok to walk back, unlike the sprint to Earth mentioned above. It’s 29.44 years to go around the beach ball for this undersized tennis ball.

Uranus is about the size of a golf ball at the 8 o’clock position but it’s just over 2 kilometres away, twice the distance of Saturn. If you were really good at hitting a golf ball you’d have to hit it about fours or five times to go that distance. You’ll spend a lifetime watching this one go once around your beach ball at 84.11 years.

Another golf ball sized object is Neptune, that’s 3.2 kilometres away at just after 9 o’clock. 164.55 years is how long you’ll have to wait for the this golf ball to do one orbit of your beach ball.

For illustrative purposes only we’ll include Pluto which is tiny. It would be a minuscule 1.8mm ball bearing (too dangerous for children under 5) about 3.6 kilometres away at about 11 o’clock. This tiny ball bearing will take 247.85 years to go around your beach ball, you’d better leave a note for your great great great great great great grandchildren to bring you some more food.

And just to show how far away things are from the Solar System, the nearest star to us would be a beach ball a bit bigger than the one on your head but 29,000 kilometres away, one tenth of the way to the Moon from the beach ball on your head.

The Solar System today, thanks to Sky Safari