Detectability of Future Earth

This special issue of the journal Futures features papers that examine the future of Earth and civilization from an astrobiological perspective, particularly focused on the extent to which human activities could be detectable across interstellar distances. As the guest editor of this special issue, my paper “Introduction: Detectability of future Earth” provides a synthesis of all the contributions in the volume.

This collection of papers demonstrates an important connection between futures studies and the search for extraterrestrial intelligence. The first issue is to examine possible future trajectories for human civilization: our growth in population and energy consumption will eventually face limits, even with advances in technology. This hybridization of the planet with technology is uncharted territory in Earth’s history, with an uncertain future or trajectory. The second issue is whether or not any other civilizations in the galaxy have already passed through this trajectory by achieving a sustainable hybridization of technology with their own planet. Evidence of such civilizations would be good news for humanity, as this would mean that our own future includes viable options for longevity. But if the search for extraterrestrial life turns up nothing, then this may indicate that energy-intensive civilizations might not be sustainable at all on a galactic scale. Our challenge as a species is to critically examine our possible futures and identify strategies for increasing the longevity of our civilization.

The collection of papers from this special issue on the Detectability of Future Earth is available on the Futures website.


Jacob Haqq-Misra (2019) Introduction: Detectability of future Earth, Futures 106: 1-3.
This special issue emphasizes the connection between the unfolding future of the Anthropocene with the search for extraterrestrial civilizations.

Brendan Mullan & Jacob Haqq-Misra (2019) Population growth, energy use, and the implications for the search for extraterrestrial intelligence, Futures 106: 4-17.
Limits to growth in population and energy consumption could occur within 2-3 centuries, which might imply that energy-intensive extraterrestrial civilizations are also rare.

Gina Riggio (2019) Earth in Human Hands, by David Grinspoon., Futures 106: 18-19.
This book review highlights Grinspoon’s observation that we are entering a new epoch of planetary self-awareness.

Julia DeMarines (2019) Light of the Stars: Alien Worlds and the Fate of the Earth, by Adam Frank., Futures 106: 20.
This book review highlights the connections between the future of Earth and the possibility of extraterrestrial civilizations.

Carl L. DeVito (2019) On the Meaning of Fermi’s paradox, Futures 106: 21-23.
This mathematical treatment of the Fermi paradox suggests that civilizations in the galaxy may emerge very slowly.

S. Stoney Simons & Jacob Haqq-Misra (2019) A trip to the moon might constrain the Fermi Paradox, Futures 106: 24-32.
Building a lunar observatory at mid-infrared wavelengths could help to improve the search for biosignatures.

Jacob Haqq-Misra (2019) Policy options for the radio detectability of Earth, Futures 106: 33-36.
Earth’s future radio detectability depends upon the risks we assume about the possibility of extraterrestrial contact.

Sanjoy M. Som (2019) Common identity as a step to civilization longevity, Futures 106: 37-43.
Civilization can extend it’s longevity through early-childhood psychology education based upon the “overview effect” of observing Earth from space.

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.

Why do we live around a yellow star?

Red dwarf stars outnumber yellow dwarf stars like our sun by over a factor of ten. Observations of exoplanets have also shown that rocky, and potentially habitable, planets are just as common around red dwarfs as yellow dwarfs. But if these much smaller stars are more commonplace, then why do we find ourselves around a yellow star like the sun, instead of a red dwarf?

My co-authors and I attempt to address this question of selection bias in a recent paper titled “Why do we find ourselves around a yellow star instead of a red star?” and published in International Journal of Astrobiology. We take a statistical approach to thinking about the region around all stars where life is most likely to develop. The liquid water habitable zone provides the best observational constraint on where we would expect to find planets that could support conscious observers like us, and this study examines the probability of finding oneself on a planet in the habitable zone of a yellow dwarf star, compared to a red dwarf. The results show that even though red dwarfs are much more numerous, they have a narrower habitable zone than yellow dwarfs, so our existence around a star like the sun is actually to be expected.

This study also considers that red dwarf stars will be even more numerous in the distant future of the universe, due to their much longer lifetimes than other stars. If these red dwarf stars will eventually become the predominant place for conscious observers to develop, then why do we not instead find ourselves around a red dwarf star billions or trillions of years into the future? The statistics for this aspect of the problem suggest that our existence around a yellow dwarf star today, compared to a red dwarf star in the future, might be a slight statistical anomaly—perhaps on the order of finding oneself born ambidextrous or with perfect pitch. But this statistical unlikelihood might also suggest that life is wholly impossibly around red dwarf stars, or else any type of conscious observers that do develop around such stars will be drastically different from our type of conscious life.

A Lottery Bond to Fund the Search for Aliens

Finding sources of funding to search for life in the universe can be tricky, with only a few individual wealthy investors and limited opportunities for government research support. New fundraising ideas are needed in order to sustain the search for extraterrestrial intelligence (SETI) over the coming decades.

In a recent paper titled “Funding the search for extraterrestrial intelligence with a lottery bond,” published in Space Policy, I propose the establishment of a “SETI Lottery Bond” to help defray the costs of operating observing facilities like the Allen Telescope Array. The SETI Lottery Bond would provide a fixed-rate of interest that continues in perpetuity, until the first confirmed discovery of extraterrestrial intelligent life, at which point a subset of shares will be awarded a prize from a lottery pool. Investors can also trade their shares, so that SETI Lottery Bond shares may be passed between generations, teaching the value of intergenerational savings while maintaining hope for the discovery of extraterrestrial life.

Lottery-based savings products can only be offered by financial institutions with the legal authorization to engage in banking and gaming activities. I propose that one or more financial institution could realize a profit through the establishment and management of a SETI Lottery Bond, while simultaneously promoting individual savings habits and assisting the search for extraterrestrial intelligent life.