Is our Universe expanding? :
“Our universe is vast and is expanding rapidly”, this is a common statement given by many experts when asked about the universe. But some questions always remain in our mind, “How do they know that the universe is expanding?” is one of them well here is its answer, scientists followed a very simple but ingenious method to find if the universe was really expanding and it is as follows:
- First they take a snapshot of the night sky and mark the distance between any two stars say A and B on an enlarged photograph of the night sky.
- Next they take a note of these readings and repeat the procedure night after night.
- After several recordings they find that the distance recorded between the stars A and B is not the same as recorded before but the distance has increased in the past few days.
- And there is the proof to say that our universe is expanding.
This is a very popular method used by the scientists the photographs are taken by telescopes specially designed for taking snapshots of the universe.
“Why is it expanding?” is also another question that pops up in our minds, well this is a tricky question to answer but some scientists believe of a gigantic explosion that took place in the universe and it is responsible for the formation of our universe and where there is an explosion there’s force, here the force or rather energy released by the explosion is still having an effect on the universe, the Big Bang has thrown away every particle involved in the bang great distances and the process is still being carried out and as a result our universe is expanding.
The Solar System:
Our solar system now has a Sun in its center and a group of eight planets revolving around it in perfect independent orbits which do not coincide with each other, Pluto was taken out from the list of planets on the basis that its orbit coincides with the orbit of Neptune.
Apart from the Sun eight planets, an asteroid belt separating the inner and the outer planets, different moons of different planets all constitute our Solar System.
Mercury, Venus, Earth and Mars constitute the inner planets and Jupiter, Saturn, Uranus and Neptune constitute the outer planets of the solar system. The planets are separated by the Asteroid Belt which consists of a large number of asteroids revolving around the sun.
Each planet also has one or more than one natural satellite called as Moon, earth has one moon, mars two, jupiter sixty three, saturn forty seven, uranus twenty seven and neptune has thirteen moons, mercury and veneus have no moons.
Apart from these our solar system also has some occasional visitors Comets. Comets are large spheres of ice and dust particles, when they approach the sun the ice melts and gives them a tail of dust and ice particles as they come close to the sun this tail usually reduces as they move away from the sun, this is why the tail of a comet always faces away from the sun.
