Stone's on Fire

        Fireballs with a long tail that passes the night sky has always been an wonderful sight to watch. During ancient , many myths were put upon in much more fascinating way about them. According to them, it even marked the beginning or the end of an civilization or kingdom and many more. Dawn and Dust - just with a click in the mind. Frame a story out of imagination whenever these glamorous fireballs pass by. Make people believe it. That's it! Mission accomplished !

Comet Representation
Photo Credit: Firstpost

    As time passed and various technologies grew and developed, physicists and scientists can now explain what these objects are and do these objects have the potential in them to reveal or fore tell the fate of a kingdom that's on Earth just by passing through the sky?

    Let's go find out!

    Kupier Belt and Oort cloud , are the place where icy objects made of frozen water and carbon-dust , in frozen form, are present. We saw about these in the previous post. These frozen objects, when its motion is disturbed by some massive star near it., somehow sends them into the inner Solar system, the region comprising Sun and its  Eight known planets. Their orbit has been changed. They now orbit Sun or whatever massive Planets that comes in their way. For now, let's just focus on the Sun.

    The frozen object, orbiting the Sun, when it comes closer to it, the heat of the Sun sublimes the icy dust it is made of. The object in this particular stage/phase is called comet! The comet has a nuclei where most of it is ice and carbon dust. It is the central part. The heat of the Sun, as I said earlier sublimes it. To bring in an analogy, it is similar to the camphor burning at pooja rooms, where the heat converts the camphor from solid directly into gas. The same happens in the comets too. The heat gives out gas and produces an atmosphere around the nuclei - it's called the coma. The solar wind pushes the dust and gas particles away forming long tails. Not just one but two tails - like the naughty children - one spewing out ionized gas and the other dust particles. Finally, a gorgeous sight for us to look into!

Inside of a comet 
Photo Credit: Encyclopedia Britannica 

    The tails of a comet can go for about millions of kilometers. The sparking of the tails is due to the reflection of light on it. The comets go around the Sun in big orbital length, when they reach the nearest side of it, they give out gases and if they do not completely die off, they go on in their orbits again. There are two categories - Short period comets which takes less than 200 years to orbit the Sun and Long period comets which takes more than 200 years to even millions to orbit the Sun!

    The repetition of the same pattern over and over gives rise to period. We may have heard about the comet Halley which takes 76 years to orbit the Sun and upon every 76th year if the comet has not been influenced by any other massive planet or if its material remains without being wiped out completely, we would keep observing it when the time approaches. 

    So, to end , the fireballs has got nothing to do with the happenings of the Earth or in determining the fate of an individual. If you happen to see a comet, enjoy observing it and don't think what it has to do with your past, present or future.

    So, until next time, bye! bye! 

The Left-Outs

                       It's so cold out there. So cold that everything's frozen. Dark and Wild. Carefree and Leisurely.  Icy and freezy. Not much sunlight left to light the space but quite an amount of gravity's left to attract and make things go around it. Things are slow. It takes about millions of years for the objects to go around the Sun once. As there's not much gravity, they don't clump together to form big planets. They are small and only range from few kilometers to few million kilometers wide. You could not expect a perfect shape from them. They are in whatever shape they like. Maybe, we can say. they are the making of their own! 

               Out there, there are more number of objects in millions or trillions- small asteroids to small planets - we are not sure about it. If you start your journey from the Sun to about a distance of  about 4.5 billion kilometers, you would reach the region after Neptune - the last known planet in our Solar System surrounded by many such objects in the shape of a donut - it's called the Kupier Belt and the objects are made of mostly ice and dust. It's in form of the a ring surrounding Neptune. Even Pluto belongs to this region but it's not a planet anymore. So let's leave it aside for some time.

Kupier Belt 
Photo Credit: NASA

           Even more far away, beyond the Kupier Belt, there is a region called Oort Cloud. To explain how it is, let me bring an analogy here. Our Earth is surrounded by so many satellites sent by us for our own use. They leave out a lot of debris when affected by sun's radiation and cosmic rays. They form up a shell around the Earth due to it's gravity. Likewise, there is a region out there, that is if you begin now, approximately after three years, if you travel in the speed of light, you would reach that region and could be able to witness it yourself. A region that is like the shell of our Solar system composed of debris that might be the remains of the formation of the Solar System. 

             

Oort Cloud
Photo Credit: abyss.uoregon.edu

                The existence of the Oort Cloud is still theoretical and unproven but they are believed to be the source of most fascinating object that we see during the night time, glowing and spewing out a lot of gas on the sky. What is the fascinating object and to know more on it, stay tuned for next update. 
          

              

          

Back Back Back

             What about some time travel? 

              It's about time to set our clocks ready. Let's set it back. Set it back to about 4.6 billions years in the past. Time is set, tighten the belts and sit comfy. Woohoo!  We are travelling through time. Don't ask if it will take a lot of time or if would be boring? Just enjoy the moment and let me wake you when you reach the destination. A destination - not the one which changes from place to place but which changes from time to time. It's not gonna take much time.  Anyways, there is more to wonder. So, off you go to sleep and rest for a while.

            Wake up sleepy eyes! We have reached. What do you see around you? Omg, where is the sun, man ?! Where are we even standing ? Where are the rocky planets - the Mercury, the Venus, our home planet Earth and our gonna-be living planet Mars and the big giant Jupiter, the ringy Saturn and the icy Uranus and Neptune? Have they disappeared ? Where the heck are their moons and why are we surrounded by dusty clouds? Hmm, it looks beautiful although it's like being in a world of clouds!!

                 Of-course, we would be wondering like this if we go back to the time before the birth of our Solar System. We are now at the outskirts of our Milky way galaxy, at the time when our Solar system is yet to be formed. It began with the gas and dust clouds called the Solar Nebula, which mostly contains matter in gaseous form. The matter may consist of atoms or ions ranging from hydrogen, helium to higher atomic numbered atoms. The kind and vastness of the particles just depends on the star that has previously died out. The nebula is as a result of a death of a big star. - to be precise - let's say it's actually the remains of a star which has ran out of fuel in its tummy and has died out eventually, by a big explosion. They have a name for this explosion too - its Supernova! 

                  The matter in these gas clouds are in continuous and random collisions with each other, eventually producing heat and they start to clump together due to their own gravity. When matters clump together, there is more mass and which means more gravity too! The more gravity it gives out the more and more matter comes together and they began to get bigger in size. If the matter mostly consists of hydrogen, then it goes on to become a star -  a thermal (nuclear) engine has been born! 

                This engine has more gravity. It attracts other minor bodies that are around, in small chunks and makes them orbit around it. The minor chunks, when they orbit the star, began to take shape. It takes a lot of years to finally cool down to a definite shape - although it always changes. They finally result as planets if they are made of higher atomic materials, if their radius is just enough to become a spherical body. The heat and radiation from the Sun does not spread out to an infinite distance. So the objects near it are heated and melted and only the matter which withstands that much heat can survive which is mostly metals and that's the reason the planets, nearest to it are solid and rocky like the four planets near it and the planets quite far away are gaseous and big like the four planets beyond Mars in our Solar System.

 What's beyond these planets? 

                 To find , stay in touch and wait for the next unravel!

  Until then , bye bye!