Waving to Aliens

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Would it be wise for humans to reach out to alien civilizations if we don't know anything about them? Scientists are trying to come up with an answer to this question. 


Sending a big hello to ET. I’m Bob Hirshon and this is Science Update.

The SETI Institute scans the heavens, looking for a beacon sent by an alien civilization. SETI researcher Douglas Vakoch thinks now it’s time for a program called Active SETI.

Active SETI involves transmitting an intentional signal saying “we want to make contact.”

At the Annual Meeting of the American Association for the Advancement of Science, he and other scientists, like David Grinspoon of the Planetary Science Institute, discussed what such a message might say and who would say it.

It’s an action that is inherently global, done on behalf of the people, or even the creatures, of Earth.

As to whether the signal might draw the attention of an evil civilization, they point out that aliens advanced enough to reach earth would also be advanced enough to pick up the light and broadcast signals we’re already producing. I’m Bob Hirshon, for AAAS, the science society.

Making Sense of the Research

SETI stands for the Search for Extraterrestrial Intelligence. Researchers in this field work to detect intelligent extraterrestrial life. Usually this involves searching the sky for radio transmissions, or optical beams that might be coming from extraterrestrials. SETI researchers are searching for messages from aliens.

In contrast, Active SETI takes a more direct approach. Instead of listening for a signal from outer space, Active SETI would involve deliberately attracting the attention of intelligent extraterrestrials by creating and transmitting messages, usually in the form of radio signals, to outer space. While "regular" SETI is a well known and approved field of research, Active SETI is still a controversial topic, which means that scientists are not in agreement about whether or not Active SETI would be a good idea.

This is why on 13 February 2015, scientists (including David Grinspoon, Seth Shostak, and David Brin) at an annual meeting of the American Association for the Advancement of Science, discussed Active SETI and whether transmitting a message to possible intelligent extraterrestrials in the cosmos was a good idea. Later that week, leading astronomers, anthropologists, and social scientists came together at the SETI institute for a symposium to begin the process of fleshing out a proposal for Active SETI and begin a dialogue that would include politicians, policy makers, and the general public.

Now try and answer these questions:

  1. What is the difference between Active SETI and regular SETI?
  2. What are some of the reasons why some think that making our presence known to advanced civilizations might be dangerous?
  3. Do you think Active SETI is a good idea? Why or why not?
  4. If we did send a message, what do you think it should be?

Visit the SETI Institute to find out more about what they do.

To learn more about the debate at the AAAS meeting, read Researchers call for interstellar messages to alien civilizations.

You also can listen to these other Science Updates about SETI:

  • Life Light examines how scientists attempt to detect the presence of extraterrestrial life from a great distance.
  • SETI at Home Upgrade discusses how you can use your personal computer to help search for extraterrestrials.

For Educators

This Science Update should be useful in sparking a student debate around the societal issues and concerns that are involved with space exploration and advanced technology. Stephen Hawking, for example, doesn't think it would be a good idea to try to actively contact alien civilizations. Neil deGrasse Tyson has suggested that advanced civilizations may be aware of us but have no desire to make contact. As such, it provides an interesting example of how scientists discuss and view issues, not just in relation to the science. It also addresses the question of whether or not we should do things just because we can. 

Related Resources

Life Light
6-12 | Audio
SETI at Home Upgrade
6-12 | Audio
South Pole Scope
6-12 | Audio

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