This more than twenty billion years timeline of our universe shows the best estimates of the occurrence of events since its beginning, up until anticipated events in the near future. Zero of the scale is the present day. A large step on the scale is one billion years, a small step one hundred million years. The past time have a minus sign, e.g. the oldest rock on Earth was formed about four billion years ago and this is marked at -4e+09 years. The "Big Bang

Big Bang

The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...

" event happened 13.7 billion years ago, see age of the Universe

Age of the universe

The age of the universe is the time elapsed since the Big Bang posited by the most widely accepted scientific model of cosmology. The best current estimate of the age of the universe is 13.75 ± 0.13 billion years within the Lambda-CDM concordance model...

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See also

• Graphical timeline of the Big Bang
  Graphical timeline of the Big Bang
  This timeline of the Big Bang shows the sequence of events as predicted by the Big Bang theory, from the beginning of time to the end of the Dark Ages....
  
  
• Graphical timeline of the Stelliferous Era. This timeline uses logarithmic scale for comparison of this article which uses ordinary linear scale.
• Graphical timeline from Big Bang to Heat Death
  Graphical timeline from Big Bang to Heat Death
  This is the timeline of the Universe from Big Bang to Heat Death scenario. The different Eras of the Universe are shown.Usually the logarithmic scale is used for such timelines but it compresses the most interesting Stelliferous Era too much as this example shows. Therefore a double-logarithmic...
  
  
• Formation and evolution of the Solar System
  Formation and evolution of the Solar System
  The formation and evolution of the Solar System is estimated to have begun 4.568 billion years ago with the gravitational collapse of a small part of a giant molecular cloud...