Our solar system is currently known to consist of eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune), five dwarf planets (Ceres, Pluto, Haumea, Makemake, Eris) and a large number of moons, asteroids, centaurs and comets. We now know that the planets orbit the Sun and that satellites (moons) orbit their host planets and that the whole system is held in equilibrium by gravity.
However, it wasn’t always so obvious. It's not very easy to explain the Solar System simply by looking at the movement of the planets from Earth because they seem to roam around the sky in a random way; an effect of us viewing an already moving object while we ourselves are moving. In fact, the word ‘planet’ comes from the ancient Greek aster planetes, meaning ‘wandering star’. Consequently, many other different models for the solar system were produced before we hit upon the correct one.
The Systema Platonicum was a model of the solar system allegedly created by Plato (427-347 BCE) with the Earth, fixed and stable at the centre, and circled by the Moon, then the Sun, Venus, Mercury, Mars, Jupiter, Saturn, and finally the sphere of fixed stars. This is similar to the Aristotelian system in which the heavens are made of crystal spheres, the first holding the Moon, the second Mercury, then Venus, the Sun, Mars, Jupiter, Saturn and then finally all the stars fixed in the furthest sphere. Aristotle (384-322 BCE) also described the universe as being made of four elements, earth, water, air and fire. Earth necessarily sat at the centre of everything as it was composed of the heaviest element.
Philolaus (c. 470 – 385 BCE) was a Greek philosopher and pupil of Pythagoras who thought that everything revolved around a central fire. He was wrong, of course, but he was probably the first person to come up with a theory that didn't have the Earth as the central planet. Aristarchus (c. 250 BCE) expanded on these ideas and got it pretty right. He had the Sun at the centre, and everything else moving around it. It should've been his name that we know, rather than Copernicus who revived it 1800 years later.
The Systema Aegyptiacum (Egyptian System) had Earth at centre orbited by the Sun and the Moon. Venus and Mercury then orbited the Sun. Outside this composite orbit came Mars, Jupiter, Saturn, and finally the sphere of fixed stars.
The great Danish astronomer Tycho Brahe (1546-1601) devised a similar system which had the Earth stationary at the centre of the universe with the Sun revolving around it. All of the other planets and comets revolved around the sun. It was liked by Tycho as it could describe the observations of the heavens as known at the time, and was consistent with the scriptures.
You teach your daughters the diameters of the planets and wonder when you are done that they do not delight in your company.
The astronomer Johanes Kepler (1571-1630) is famed for discovered the laws of planetary motion; in particular, their elliptical orbits. However, his first attempt at describing the solar system involved him inventing a new (invisible due to its smallness) planet in between Mars and Jupiter and another between Mercury and Venus in order for his system to make sense. He later subscribed to the view that the planets sat inside hollow spheres, nestled like Russian dolls, and separated by hollow versions of each of the five Platonic solids.
A platonic solid is a geometric shape that can be made from smaller identical regular shapes. There are five: a tetrahedron is made from four identical regular triangles; a hexahedron is made of six identical regular squares; an octahedron from eight identical equilateral triangles, a dodecahedron from twelve identical pentagons; and an icosahedron from twenty identical equilateral triangles. They were supposedly discovered by Plato - hence the name - around 350 BCE, although there is evidence that stone-age Scots knew about them. Kepler’s model was of a sphere inside a tetrahedron inside a larger sphere inside a cube inside an even bigger sphere… and so on.
Kepler had an ingenious solution to get the idea across: alcohol. He designed a silver model of his universe in which each planet's Platonic solid would dispense a different booze through little taps; brandy from Mercury, mead from Venus, strong vermouth from Mars and a delicious new wine from Jupiter. He even suggested that Saturn should be filled with a bad red wine, so that people could ‘ridicule those ignorant of the planet's bitter qualities.’ Sadly, the model simply wouldn't fit together but drawings still exist to show us what it could have looked like.
Eventually Kepler would come up with the model that is familiar today, in which the orbit of each planet can be described as an ellipse. That said, he didn't really understand why it worked - Newton's gravitational laws were the best part of 100 years away - so he was reduced to the speculation that the planets were moved in their orbits by angels.
The solar system has no anxiety about its reputation.
Galileo (1564-1642), who was famously put under house arrest for claiming that Copernicus was correct and the Earth went around the Sun, made his decision to turn to Copernicus's model of the solar system after he discovered that all Copernicans were former Aristotelians, but he could find no evidence of anyone converting the other way around.
The village of Otford in Kent, England contains a 1: 5 billion scale model of the solar system centred on the village recreation ground.
A supergiant star can be as large as our entire solar system.
It wasn't until 1992 that The Catholic Church finally admitted that Galileo's views on the solar system were correct.
The solar sytem is travelling round the Galaxy at more than half a million miles per hour.
From when it was discovered, until the time it was demoted as a planet, Pluto had only completed a third of an orbit of the sun.
NASA scientists have made a recipe of the gases on Saturn’s moon Titan. It smells like a mixture of petrol and farts.
Mars rover Curiosity took 65 bacterial species that survived the prelaunch cleaning process to Mars. Nobody knows if any of them survived.