The Sun is 400 times larger than the Moon but is 400 times farther away from Earth, making them appear the same size.
Today is the 35th anniversary of the launch of Voyager 1.
The number of stars in the observable universe is also about equal to the number of atoms in 6 grams of carbon-12.
It cost around $2.5 billion to send Curiosity to Mars. That’s kind of a bargain if you consider that a line of dollars, laid end-to-end from Earth to Mars, would add up to $1.6 trillion.
Learn about this and other fun calculations done with the dollar on our blog.