Decoding Intragalactic Communication
Astronomy
Name:
Date:
Background: Any highly technological species that might be looking at our corner of the Milky Way may
be able to detect us going about our every day business. We emit microwaves and radio waves in the
form of television and radio broadcasts and other communications, in addition to the electrical lights
visible on the night side of our planet. A few organized efforts have been made to reach out intentionally
including the Pioneer Plaque (1972), the Aricebo Message (1974) and the Voyager Records (1977). In
this activity, you will consider what message would be logical to broadcast, and analyze the abovementioned efforts.
1. Assume that you are tasked to decide 5 facts or ideas that will be broadcast to a potential intelligent
species. Agree as a group what these 5 things would be and list them below.
2. If we were to attempt to communicate with other intelligent life, how might we find and get in touch
with them (remember that we can’t use Earth language!)
3. Study the diagram below. Assume that this is a message sent to us by aliens. What do you think the
shapes represent? Do your best to decode this message.
4. Repeat your process from #3. Do your best to decode these two diagrams.
5. Even if intelligent life can’t decipher our message, would it still be worth sending? Why or why not?
6. a. The diagram in #3 is the Arecibo message. Look this up on your phone and label the diagram with
the correct interpretation.
b. The diagrams from #4 are the Pioneer Plaque and the Voyager Gold Record. Look these up and label
the diagram with the correct information.
7. What information is common to the Arecibo message, the Pioneer Plaque and the Voyager Records?
8. In what ways are those messages different from the information that your group agreed on in #1?
Discussion
1 Discuss the meaning behind the statement "absence of evidence is not evidence of absence" as it relates to
the search for extraterrestrial life. Why has this become a slogan of the SETI program?
2 If scientists ever determine for certain that intelligent life exists on other planets, it will probably have a
tremendous effect on society. How would we be changed by such an earth-shattering discovery? What
developments might we expect to see in the areas of religion, culture, and politics in particular?
3 Science fiction writers use extraterrestrials in stories not only to tap into readers' primal fears, but also as
mirrors of ourselves—encouraging us to face difficult social, political, and environmental issues. For
example, in the story "Before Eden" by Sir Arthur C. Clarke, the first plants discovered on another planet
are accidentally destroyed by a bag of waste left behind by human explorers. The story subtly encourages
readers to think about the effects of our environmental excesses. Think about the images of aliens you have
seen in movies and television or read about in books. What "messages" did those movies, television shows,
or books contain? Do you think it's useful for a writer to use images of aliens to send messages to humans?
Why or why not?