Astrophysics timeline

When did astronomy start?

The earliest astronomical records and star catalogs were kept by the Sumerians, then Babylonians, with the earliest known clay tablets recording the position of the planets, and solar eclipses dating to around 1600 BCE

\nThis is the timeline of the stelliferous era but also partly charts the primordial era

And charts more of the degenerate era of the heat death scenario.

Visual timeline of the universe

This more than 20-billion-year timeline of our universe shows the best estimates of major events from the universe's beginning to anticipated future events. Zero on 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 is denoted by 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

Where 4e+09 represents 4 times 10 to the power of 9.The Big Bang event most likely happened 13.8 billion years ago; see age of the universe.