Age of the universe

time elapsed since the universe emerged with the Big Bang

In cosmology, the age of the universe is the amount of time since the Big Bang. The best measurement of the age of the Universe is 13.8 billion years (specifically, 13.798±0.037 billion years).[1][2] The most recent and most accurate measurements were made by the Planck spacecraft. These measurements were made using the cosmic microwave background radiation and the expansion of the Universe.


In the 1800s, evidence from geology showed that the Earth was at least millions of years old. Later, it was thought that the universe was unchanging. However, in the 1920s, Georges Lemaître and Edwin Hubble determined that the universe was expanding (see Hubble's law). Although the estimates made using the initial data were low, radioactive dating on Earth could be used to give measurements of 11–20 billion years[3] to 13–15 billion years.[4][5] Eventually, scientists were able to make much better measurements using spacecraft.

Ultimate fateEdit

Essentially unknown, but the fate of planet Earth is known. The Sun will eventually become a red giant and consume the Earth.[6]


  1. Planck Collaboration (2013), Planck 2013 results. I. Overview of products and scientific results
  2. Bennett C.L.; et al. (2013), Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
  3. Britt RR (2003-01-03). "Age of Universe Revised, Again". Retrieved 2007-01-08.
  4. Wright EL (2005). "Age of the Universe". UCLA. Retrieved 2007-01-08.
  5. Krauss LM, Chaboyer B (2003). "Age Estimates of Globular Clusters in the Milky Way: Constraints on Cosmology". Science. American Association for the Advancement of Science. 299 (5603): 65–69. doi:10.1126/science.1075631. PMID 12511641. S2CID 10814581. Retrieved 2007-01-08.
  6. Blackman, Joshua; Bennett, David; Beaulieu, Jean-Philippe 2021. A Crystal Ball Into Our Solar System's Future - Giant Gas Planet Orbiting a Dead Star Gives Glimpse Into the Predicted Aftermath of our Sun's Demise. Keck Observatory. [1]