This timeline attempts to show the best scientific estimates of the timings of past events and predictions of the approximate timing of hypothetical future events with cosmological significance. Some locally significant events of interest to members of Homo sapiens are also included. See Dating Creation for alternative views based on religious tradition. (Note: in this context, billion means 1,000,000,000).

The Big Bang

• 13.7 ± 0.2 billion years ago: Universe, which includes time and space, begins with Big Bang
  • Note: the Big Bang is dated according to NASA's Wilkinson Microwave Anisotropy Probe (WMAP) data

See also timeline of the Big Bang for the first 300,000 years after the Big Bang.

The distant past

• 300 thousand years after the Big Bang, hydrogen nuclei capture electrons, forming the first atoms
• 600 million years after the Big Bang: formation of first galaxies, see Galaxy formation and evolution
• 5 billion years ago (~8.7 billion years after the Big Bang): formation of the Sun
• 4.5 billion years ago: formation of the Earth -- start of geologic timescale
• 3.5 billion years ago: first signs of single-celled life on Earth
• 600 to 500 million years ago: multicellular life evolves

The human era

• 2.5 to 2 million years ago: appearance of the genus Homo (see human evolution)
• about 150,000 years ago: appearance of Homo sapiens
• for the past and present of mankind, see centuries
  • 12 to 10 thousand years ago (the Holocene epoch): Homo sapiens invent agriculture; start of human civilization
  • 1961: men first orbit the Earth in spacecraft

...

• 40,000 years from now, Voyager 2 will approach another planetary system.

The far future

• 3 billion years from now: Milky Way and Andromeda collide
• 5 billion years from now: the Sun becomes a red giant

See also 10¹⁹ seconds for times further than 3 billion years into the future.

See also:

• Creation of the Universe for more on creation scenarios other than the Big Bang
• End of the Universe for theories about possible final fates for the Universe
• Exponential timeline shows all history on one page in ten lines.