The Cosmic Calendar

Erika Grundstrom
Vanderbilt University & Fisk University
Author Profile
Initial Publication Date: February 23, 2012 | Reviewed: November 3, 2013


In this activity, one takes ALL of time, from the beginning of time (i.e., the Big Bang) all the way up to today, but one compresses it into one year. One can do this for all levels of students depending on how much work you want them to do in figuring out which events to include, exactly when they should take place on the Cosmic Calendar, how you want them to display it...
This activity was adapted by the Astronomical Society of the Pacific from a wonderful exercise popularized by Dr. Carl Sagan, astronomy publicizer extraordinaire.

One can easily modify this to just include time from Earth's formation until now.

Used this activity? Share your experiences and modifications



I have used this activity for students from fourth grade to undergraduate majors (in an astronomy context) - it all depends on how much you want them to do.

Skills and concepts that students must have mastered

For all ages, they need to know what a calendar is.

For younger ages, they should know how to put events in order.
For older ages, they should know how to do ratios.

How the activity is situated in the course

Most often, I have done this as a stand-alone exercise, sometimes during one-off guest speaker engagements. During my introductory astronomy course, we spend some time on this (homework and in-class activity) as part of a larger context.
It COULD be used as many other things, I just haven't done so personally.


Content/concepts goals for this activity

Content goals: important events in the Universe's history, ratios

Concept goals: arithmetic as a tool to learn about the Universe, vast time scales in the Universe, evolution has the time it needs!, human insignificance ;)

Higher order thinking skills goals for this activity

synthesis of ideas (math, anthropology, astronomy, biology, geology)

Other skills goals for this activity

One COULD engage these skills:
- searching the internet
- working in groups
- operating calculators
- writing about particular events or a reaction to the activity (like what it means)

Description of the activity/assignment

This activity from the Astronomical Society of the Pacific asks students to compress all of time (from the Big Bang until now) into one year.
First, they have to pick major events (younger students can be given them) - this can lead to lively discussion! You can certainly be adaptable here.
Second, the best thing to do is have the students guess where each event should be on the Cosmic Calendar.
Third, have them look up or be given the actual time period when the event occurred.
Fourth, have them calculate (or be given) the "date" on the Cosmic Calendar.
Fifth, discuss! Debate! Reflect!

Files cannot be uploaded as they are copyrighted but they are easily found and freely available.
Authors: Therese Puyau Blanchard, Andrew Fraknoi, and the staff of the Astronomical Society of the Pacific

Determining whether students have met the goals

- writing a reflection
- filling out a worksheet
- answering multiple-choice test questions

More information about assessment tools and techniques.

Teaching materials and tips

Other Materials

Supporting references/URLs

This activity may be found on the Astronomical Society of the Pacific's website - it is part of their "Universe at Your Fingertips" lesson series. Authors: Therese Puyau Blanchard, Andrew Fraknoi, and the staff of the Astronomical Society of the Pacific.

Wikipedia has an excellent article on the Cosmic Calendar: