Did you know?
Mass of Umbriel (moon of Uranus) (1.17 sextillion kg) is 400 x Mass of Puck (moon of Uranus) (2.9 quintillion kg)
Tweet this comparison
Pop. of Johannesburg, South Africa (4.43 million people)
Yes, there's now a book based on these numbers. Oxford University Press: July 2018.
Click here to learn more about it.
Click here for Podcast: Andrew Elliott interviewed for New Books Network.