Formation of Galaxies and Stars

Credits – EurekAlert

• With the initial difference in densities of matter and energy, the gravitational forces originated.
  • This caused the matter to come together.
• The basis of galaxies is thus due to these formations.
• Galaxy is an amalgamation of a number of stars.
• These galaxies are thousands of light-years apart.
• Individual galaxies have diameters in the range of 85,000 to 150,000 light years.
• Nebula – A large cloud formed due to the accumulation of hydrogen gas.
  • The Nebula develops into localized lumps of gas.
• The localized clumps further begin to grow denser, resulting in the formation of stars.
  • These stars started to form some 5-6 billion years ago.

Formation of Planets

Credits – Nature

Formation of Planets took place in the following stages –

Stage 1

• Stars are localized lumps of gas within a nebula. Due to difference in density and hence emergence of gravitational force.
• This gravitational force in the lumps leads to formation of a core. This gas core has a huge rotating gas disc and a gas cloud around it.

Stage 2

• In the second stage, the condensation of the gas cloud takes place.
• As a result, the matter developed around the gas core convert into small round shaped objects.
• Due to the process of cohesion, the small round shaped objects develop into planetesimals.
• Thus, due to the collision between these planetesimals, larger bodies are formed.
• The gravitational forces help the larger bodies to stick together.

Stage 3

• In the final stage, as a result of the small planetesimals coming together, fewer large shaped bodies are formed called the Planets.