The Risk of Transmitting to Space

The idea of messaging to extraterrestrial intelligence (METI) suggests that a possible way to establish contact with civilizations on other planets is to first send transmissions ourselves. The search for extraterrestrial intelligence (SETI) has traditionally followed a passive listen-only mode to detect any alien transmissions headed our way. If everyone is listening and nobody is transmitting, then METI might be the way to attract attention.

But is attracting attention from extraterrestrial civilizations necessarily good? We have no idea if contact with extraterrestrial beings would benefit or harm humanity, or even be completely neutral in its impact. Some scientists are unconcerned about possible risks and suggest that METI transmissions should occur whenever they are viable. Others worry that METI transmissions could expose Earth to significant risk and argue in favor of a moratorium on METI activities.

I recently published a paper titled “Policy options for the radio detectability of Earth” in the Futures special issue on the Detectability of Future Earth. In this paper, I argue that the METI risk problem cannot be conclusively decided until contact with extraterrestrial intelligence actually occurs. This implies that any moratorium on METI activities cannot be based on the requirement for new information, as the only new information that would actually suffice is the actual discovery of alien life. Following from this conclusion, there are three possible policy options for proceeding with SETI and METI:

  1. Precautionary malevolence – alien contact is likely to be harmful, so we should not engage in METI until SETI succeeds.
  2. Assumed benevolence – alien contact is likely to be helpful, so we should engage in METI along with SETI.
  3. Preliminary neutrality – alien contact is unlikely to occur at all, so we may as well do SETI and METI if funds are available.

All three of these policies remain viable options until we actually discover extraterrestrial intelligence and learn the actual risks to humanity. Precautionary malevolence would imply that human civilization should reduce all of its transmission activities so as to minimize its detectability by alien observers. Likewise, assumed benevolence implies that greater transmissions from Earth would increase the chances of contact. But both of these policies are optimistic about the likelihood of contact with alien life. Perhaps a more pragmatic approach is preliminary neutrality, which would remain consistent with business-as-usual on Earth and would not recommend any significant changes to Earth’s future detectability.

An “Ecological Compass”

Only recently have humans gained the capability to willfully and technologically manipulate the environment on a global scale. This sort of planetary engineering includes present-day geoengineering proposals to counteract anthropogenic climate change by reflecting away a fraction of incoming sunlight. Although such a feat seems technically achievable, whether or not we should engage in such geoengineering is a question of ethics. Other, more futuristic, kinds of planetary engineering include plans for terraforming Mars to increase global temperatures and make the red planet habitable for Earth life. For terraforming as well, the technology for terraforming may be available today, but whether or not we should deliberately modify another planet is a question of ethics.

I recently published a paper in the journal Astrobiology that develops a two-axis framework for comparing different views about how we value organisms, environments, planetary systems, and space. The ecological compass is shown in this figure with a scale from “space” to “intelligence” along the horizontal axis. This axis is intended to represent the vast diversity of life on Earth, from humans and other animals on the far right, to microscopic organisms near the middle, to planetary systems and space on the far left. The vertical axis of the ecological compass contrasts two types of value: instrumental value and intrinsic value. Instrumental value describes the usefulness or purpose that an object, organism, or system provides; for example, a logger may assign instrumental value to trees that are grown for lumber. Intrinsic value describes the an object, organism, or system as valuable for its own sake; in this sense, a hiker may view a tree as valuable simply by virtue of its being a tree. With this two-axis system, we can describe and compare various attitudes toward nature and their implications for planetary engineering.

An anthropocentric view, which assigns instrumental value to all life other than humans, may find no environmental objection to planetary engineering. This is because anthropocentrism is only concerned with the effects of planetary engineering on humans. A zoocentric (or ratiocentric) framework extends intrinsic value to animals and gives at least some consideration to how human actions affect these organisms. As such, zoocentrism suggests that some consideration should be given to the effects of geoenginering on non-human animals. Likewise, a macrocentric viewpoint considers large, visible organisms as intrinsically valuable, while a microcentric viewpoint considers even microorganisms to possess intrinsic value. Under these ethical frameworks, the decision to terraform a planet such as Mars will depend upon the organisms that are already inhabiting it. Finally, a cosmocentric framework places intrinsic value across the entire biological spectrum from intelligent creatures and microorganisms to planets and space. This suggests that a cosmocentric ethical framework would refrain from any sort of planetary engineering because a planet is valued for its own sake.

This ecological compass is intended to be used as a tool for discussions of human valuation of nature. As a tool it cannot provide the answer to whether or not we should engage in planetary engineering, but it can at least help us raise important questions about how we value nature in advance of any decisions.

Sending Messages Into Space

One possibility for communicating across the vast distances of space is the use of radio or other electromagnetic waves. Human civilization already posses the technology to broadcast and receive signals at many wavelengths. If other extraterrestrial civilizations exist in the galaxy, then it is possible that they could develop similar capabilities. Based on this premise, the search for extraterrestrial intelligence (SETI) has scanned the sky for over fifty years now to look for any such signals. Along similar lines, a handful of attempts at messaging to extraterrestrial intelligence (METI) have been undertaken in recent years, with hopes of being picked up by an extraterrestrial listener. The content of these messages has increased in complexity and content, though, which may produce cryptic messages that are disorganized or difficult to decipher.

In a recent paper published in the journal Space Policy, my co-authors Dimitra Atri and Julia DeMarines and I propose the development of a METI protocol in order to guide the construction and transmission of messages to extraterrestrials. A METI protocol would include technical considerations such as the method of signal encoding, message length, and transmission strategy. This protocol would also provide guidelines for the content of messages, which includes limits on culturally-dependent, anthropocentric, or sense-dependent information. This will help ensure that a message into space is more representative of Earth as a whole and may also increase the likelihood that the message is understood by potential listeners.

As a way of testing messages and promoting educational outreach, we will implement an interactive website in which users can attempt to submit or decrypt messages according to a METI protocol. This will allow messages to be tested across cultural borders, which arguably is a minimum requirement for a message that would be sent to unknown extraterrestrial listeners. Such an exchange will also help users of the website to gain insight into cultures other than their own by discovering success or failure at effectively communicating a message to unknown receivers on Earth.