Finding Life Beyond Earth

Within our solar system, NASA’s missions have searched for signs of both ancient and current life, especially on Mars and soon, Jupiter’s moon Europa. Beyond our solar system, missions, such as Kepler and TESS, are revealing thousands of planets orbiting other stars. 

The explosion of knowledge of planets orbiting other stars, called exoplanets, and the results of decades of research on signatures of life - what scientists call biosignatures - have encouraged NASA to address, in a scientifically rigorous way, whether humanity is alone. Beyond searching for evidence of just microbial life, NASA now is exploring ways to search for life advanced enough to create technology.

Technosignatures are signs or signals, which if observed, would allow us to infer the existence of technological life elsewhere in the universe. The best-known techno-signature are radio signals, but there are many others that have not been explored fully. 

In April 2018, new interest arose in Congress for NASA to begin supporting the scientific search for technosignatures as part of the agency’s search for life. As part of that effort, the agency is hosting the NASA Technosignatures Workshop in Houston on Sept. 26-28, 2018, with the purpose of assessing the current state of the field, the most promising avenues of research in technosignatures and where investments could be made to advance the science. A major goal is to identify how NASA could best support this endeavor through partnerships with private and philanthropic organizations. 

What are Technosignatures? 

The term technosignatures has a broader meaning than the historically used “search for extraterrestrial intelligence,” or SETI, which has generally been limited to communication signals. Technosignatures like radio or laser emissions, signs of massive structures or an atmosphere full of pollutants could imply intelligence. 

In recent decades, the private and philanthropic sectors have carried out this research. They have used such methods as searching for patterns in low-band radio frequencies using radio telescopes. Indeed, humanity's own radio and television broadcasts have been drifting into space for a number of years. NASA’s SETI program was ended in 1993 after Congress, operating under a budget deficit and decreased political support canceled funding for a high-resolution microwave survey of the skies. Since then, NASA’s efforts have been directed towards furthering our fundamental understanding of life itself, its origins and the habitability of other bodies in our solar system and galaxy. 

Where are all the aliens?

Our Sun is just one star among billions in our galaxy. In the last few years, scientists have detected thousands of planets around other stars and it seems that most stars have planetary systems. It’s therefore likely that there will be large numbers of habitable planets in the Milky Way galaxy and beyond that are capable of supporting intelligent life. Some of these intelligent civilizations, if they’re out there, may have even developed interstellar travel.