Solar System – An Olympic Ground !!

Our solar system is a very big olympic ground.

Solar System

The planets, including our Earth, runs along the track on an endless marathon. And the center of attention here is the Sun.

Before we proceed, I’d like to clear one thing; Solar system consists of a Sun and “eight” planets.The International Astronomical Union took out Pluto from the list of planets saying that it isn’t actually a planet. Now pluto represents a Dwarf planet.

Solar System - Another Picture

How do we define the Solar System?

The Solar System is as vast as the gravitational field of the Sun. Theoretically (means “the actual truth”), the gravitational field of the Sun extends to infinity. But, for practical purpose(like here, for our convenience), we assume it to have a boundary right outside the orbit of the last planet.

Internationally, the extent of the solar system is the largest orbit of its comet. Who knows, maybe there is comet that visits the Sun every 1,000,000 years. In that case, the comet might have a very large orbital radius and so the solar system is as big as that orbit. Any way, if we leave out the comets, and consider the planets alone, the Solar System is as big as the orbit of the 8th planet.

Who all are there in the solar system?

The Sun just one Star in the sky. In fact it is the closest star to our Earth(explains why we see it as the biggest star). A few planets revolve around it. A few satellites(not the man made ones, but those like the moon) revolve around the planets. We can also find asteroids and meteors in the solar system too.

And, we often get visited by Comets (but Uncle Jupiter just eats most of them)

How was our Solar System born?

The kids may not understand the answer to this. So let me put it into practical terms. Take a large bowl of water. Put a fairly large number of small ants in it. Initially , the ants will be scattered, but soon they will join with each other to make an “ant patch” on the water (a few of them  die and a few of them stands away from the pack, Anyway, you get the idea, right?)

So, the ants join into one big group in due course of time.

Just like that, there was so much of dust in some part of the universe.Now kids, even dust has a gravitational field. So, each dust particle attracted every other dust particle near him. Soon they got closer and closer to each other and became something similar to a sandstorm.

Nebula

This is what we call a Nebula. It is just a vast amount of space dust, where stars are born. Our solar system evolved out from a nebula called “Solar Nebula”.

At first, it was just a giant dust ball. But it took years to form into a plate. The thickness is negligible when compared to the extent of it. The disc rotated and it started to shrink, because of gravity. Then the mass at the centre got bigger and denser and its temperature started to rise. The dense materials like metals and minerals were in the molten state and was near the hot centre. Outside there was just gas.

The centre formed into the hot sun. The molten metals and minerals formed into Terrestrial planets and the gases formed into Jovian planets. And sometimes, these big boys hit on each other, thus breaking into small pieces called asteroids. They are like rock chunks.

Space Collision

These asteroids, when they move as really small groups or alone, are called meteors and their kids are called meteorites. Comets are similar to meteors but are of a different level of status. Like the difference between the prince and the peasant, the prince being a comet.

All this didn’t happen in one day. It took 4.6 billion years for the dust cloud to become the solar system.

Mercury, Venus, Earth and Mars are the terrestrial planets. There  core are dense materials.

Jupiter, Saturn, Uranus and Neptune are the Jovian planets. There cores are gaseous.