Evolution of Universe

                           Big Bang Theory 

The Big bang hypothesis states that all of the current and past matter in the Universe came into existence  at the same time , roughly 13.8 billion years ago.  During this time all matter was compacted into a very small ball with infinite density and intense heat known as Singularity. The universe existence began when suddenly Singularity began expanding .

  

                       Birth Of The First Element

After Big bang , the universe was both too hot and too dense for the element formation . The origin of hydrogen came into existence when universe began to spread out and cooled subsequently enough for first protons and neutrons, and later simple atoms to form. The condition suitable for the protons and neutrons  to form hydrogen nuclei is called era of nucleosynthesis. Few of these nuclei combined to form helium. .

  

               Origin Of Ancient Star

Its revealed by the observation that tiny clumps of matter were formed in the baby universe , these clumps are seen as tiny temperature differences of less than one millionth of a degree , more matter was pulled by the areas of lower density and these clumps grew. After about 200 million years of this clumping, there was enough matter in one place that the temperature got high enough for nuclear fusion providing the fuel for stars to glow . 

       Formation Of The Big Nebulas

Its an Interstellar cloud of dust made of hydrogen, helium and ionized gasses. It was a name initially given for any diffuse cosmic object , including galaxies past the Milky Way. These are tremendous in size , as great as many light years in diameter. In these areas the development of gases , dust and different materials cluster together to frame denser regions that draws in more matter and inevitably wind up plainly sufficiently to shape stars. The Tarantula Nebula stretches for more than 1800 light years at its longest span.

                        Formation Of Planets 

The origin of planets are thought to be solar nebula the disc shaped clouds of gas and dust left over's from the Sun's formation. Currently accepted method for the planets formation is accretion, in which planets began as dust grains in orbit around the center proto star. The nearest planets to the star tends to be rockier because stars winds blow away  their gases and because they are made of heavier materials attracted by the star's gravity.  Astronomers have discovered one of the oldest planetary system . In March 2012 European astronomers announced the discovery of planetary system around a metal poor star which is a star containing only hydrogen and helium . The star is HIP11952 and apart from being very ancient star known to have planets is also estimated to be around 12.8 billion years old this exoplanet system is one of the oldest .

               

     Formation Of The Natural Satellites

The natural satellite is a celestial body in space that orbits around a large body. Moons are called natural satellites because they orbit planets. These are thought to be formed by the same collapsing region of the proto planetary disc that created its primary.  There are 243 known moons within the solar system including 163 moons orbiting the planets four orbiting dwarf planets and dozen more  orbiting small solar system bodies.  Ganymede is the largest moon in the solar system (larger than the planet mercury) and is the only moon known to have its own internally generated magnetic field .