Just as a scale model of the solar system can help us understand the vastness of space, the Cosmic Calendar can help us understand the age of the universe and its inhabitants. From a concept first popularized by Carl Sagan in the original Cosmos, this Cosmic Calendar is in poster form and can be printed out for free, for display and reference. You can download it as a pdf file here, or click the image above for access to a larger jpg file. At 300 dpi resolution, the image is a borderless 11″ x 17″. While you are welcome to make your own prints for free, you can also buy the image on posters, t-shirts, and other products at Redbubble.

In the Cosmic Calendar, we compress all of time into a single year, imagining that the Big Bang happened at midnight on January 1 and it is now midnight on December 31.

It’s amazing to think that more than two billion years passed between the Big Bang and the formation of our Milky Way Galaxy, and then more than six billion more years passed before the Sun and Earth were formed. In the Cosmic Calendar, so much of what we think of as ancient events, such as the appearance of the first animals and land plants, and the evolution of fish into amphibians and reptiles, actually take place in late December. We think of the extinction of the dinosaurs as happening a very long time ago, but in the Cosmic Calendar it happened just yesterday, on December 30. And human history? As Carl Sagan put it, “We’ve emerged so recently that the familiar events of our recorded history occupy only the last seconds of the last minute of December 31st.”

We recently heard from a teacher in Australia who had the calendar printed on stretch canvas at 20″ x 30″ with good results, as seen below.