Home > Astronomy > Time Scale of the Cosmos

How many years after the Big Bang did the planets form?

Answer 1

If you are referring to our planets, the ones in our solar system, they formed about 4.6 billion years ago, while the Big Bang was 13.8 billion years ago.

If referring to the planets in our solar system, they formed #13.8-4.6=9.2# billion years later. But our planets are not the only ones - we have detected many planets in other systems, with the oldest detected planets being around 12.8 billion years old, so they formed about 1 billion years after the big bang.

It is possible that there are undiscovered planets that are even older.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Ian Aitchison

Planets began to form roughly 9 billion years after the Big Bang, as the universe cooled and matter coalesced into stars and planetary systems.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.