How was it formed?
Our Solar System is made up of a star, eight major planets and their satellites, some minor planets and their satellites, numerous comets, asteroids and meteorites.
It is very difficult to show the size of the solar system. Many diagrams exist showing the sun and planets but it is nearly impossible to achieve an exact scale model. This is mainly due to the fact that, in astronomical terms, the planets are tiny and the distance between them is enormous.
If you drove once around the Earth you would have gone 25,000 miles. That would mean 40 to 50 days of driving to just go around once. The Earth is 93 million miles from the sun. A 747 jet flies at about 600 miles in one hour. If we could take a 747 jet to the Sun, it would take 17 years to reach the star.
As we move farther away from the Earth, distances get so large so fast that astronomers have to use the fastest speed possible – the speed of light (186,000 miles every second). Light can go around the Earth 7 and 1/2 times in one second. It takes light 1 and 1/2 seconds to go from the Earth to the Moon, 240,000 miles. It takes 8 minutes for the light of the Sun to reach us. It takes 5 light-hours (meaning the distance light travels in 5 hours) for light to get out to Pluto from the Earth.
Planets of our Solar System
What is the Scale of Our Solar System?
Although we think our planet is very large, when we compare it to other objects in our solar system, it is really quite small. We could fit 1000 Earths inside Jupiter. And we could fit 1000 Jupiters inside the Sun. It would take one million Earths to fill the Sun, and our Sun is only about a medium-sized star. As we move outside our solar system, distances get so large that a different type of measurement must be used. The light year.
When we look up at stars at night, we are seeing light that left the star a long time ago. The light from Proxima Centauri, the nearest star, takes 4 years to get here. When we look at the fuzzy circle of a distant galaxy, we are seeing light that left that galaxy at least 2 million years ago. Even when we take a look at the our sun (not recommended with the naked eye), we actually see the sun as it was 8 minutes ago. This is because it takes 8 minutes for the light of the sun to reach us.
Solar System Facts:
- The solar system includes the Sun and all the objects that orbit around it due to its gravity. This includes things such as planets, comets, asteroids, meteoroids and moons.
- The Solar System formed around 4.6 billion years ago.
- There are eight planets in the Solar System. The four inner planets are Mercury, Venus, Earth and Mars while the four outer planets are Jupiter, Saturn, Uranus and Neptune.
- The inner planets (also known as terrestrial planets) are smaller and made mostly of rock and metal.
- The outer planets (also known as gas giants) are much larger and made mostly of hydrogen, helium and other gases.
- As of 2008, there are also five dwarf planets: Pluto, Ceres, Eris, Makemake & Haumea.
- There is an asteroid belt which lies between the orbits or Mars and Jupiter, it features a large number of irregular shaped asteroids.
- For thousands of years humans were unaware of the Solar System and believed that Earth was at the center of the Universe.
- Astronomers such as Nicolaus Copernicus, Galileo Galilei, Johannes Kepler and Isaac Newton helped develop a new model that explained the movement of the planets with the Sun at the center of the Solar System.
- The Sun contains 99.86 percent of the Solar System’s known mass, with Jupiter and Saturn making up making up most of the rest. The small inner planets which include Mercury, Venus, Earth and Mars make up a very small percentage of the Solar System’s mass.