In the quest to answer “What Technology Do Astronomers Use to Search For Extraterrestrial Life?”, the hunt for intelligent beings beyond Earth is ramping up. As UAP news consistently captures global attention, SETI’s pursuit is inching closer to the forefront of NASA’s agenda. This past January, a dedicated group of scientists convened, committed to reintroducing SETI into NASA’s spotlight. To truly unlock the secrets of the universe, astronomers are banking on tools like the soon-to-be-completed Giant Magellan Telescope. With its immense resolving power, it’s the beacon of hope in detecting telltale chemical signatures, like atmospheric oxygen, on distant exoplanets, indicating potential life.
Radio and Laser Signals
Astronomers employ radio telescope arrays to search for evidence of alien civilizations’ signals – known as technosignatures – as well as looking out for signs from Earth such as radio waves leaking from cell towers or television antennas. When completed in 2024, the new Square Kilometre Array will be 50 times more sensitive in detecting signals at distances reaching one star system.
Project Ozma was initiated by Frank Drake using a radio telescope at Green Bank, West Virginia (SN Online: 11/1/09). Nowadays, large telescopes monitor the sky for radio or laser pulses that might indicate intelligent life (SN Online: 11/1/09).
Astronomers observe radio wave emissions that might indicate ET presence, such as hydrogen and oxygen atomic lines released when living organisms break down water molecules. Such a signal typically has frequencies between one and 10 gigahertz.
Scientists may not have found evidence of alien communication just yet, but that hasn’t stopped them from searching. Telescopes such as the Arecibo observatory generate massive amounts of data and through the SETI@home program non-scientists worldwide can contribute in analyzing it on their home computers. Furthermore, searches continue for chemical pollutants produced by human industry such as nitrogen dioxide and chlorofluorocarbons; on exoplanets the detection of high concentrations of atmospheric gases like carbon dioxide and oxygen may indicate living organisms producing them through photosynthesis.
Biosignatures
Astronomers are also searching for signs of life outside radio signals in the form of biosignatures, including atmospheric chemical disequilibria or complex chemical networks in planet atmospheres that could indicate whether or not an alien civilization inhabited this particular world. Remote sensing techniques allow us to detect these biosignatures which could tell us whether or not a planet is habitable.
Researching biosignatures does not come without its challenges, however. There has been an increased realization that these biosignatures may not always be reliable and must be carefully assessed to avoid false positives or “abiosignatures,” caused by non-biotic processes on Earth. As a result, researchers must carefully consider both environmental context and multiple lines of evidence when making interpretations and claims about interpretations.
Astronomers face another difficulty when searching for biological biosignatures on planets with no obvious surface features, as this requires them to distinguish biosignatures from non-biological features such as clouds, hazes and seasonal gas abundance patterns. This work has come to be known as space archaeology; with scientists from disciplines including astrophysics, geochemistry planetary science and geology all contributing their expertise towards making significant strides forward in future studies.
Some astronomers are actively engaged in searching for technosignatures – or signs of alien technology – such as electromagnetic messages or massive structures like monoliths. Although no confirmed technosignature has yet been found, this research is conducted alongside SETI.
Chemical Pollutants
Astronomers are searching for signs of life on distant planets known as exoplanets, such as oxygen and methane that wouldn’t otherwise exist without life. A device called a spectrograph can pick out these gases by picking out their chemical signature in starlight from exoplanets; this technique belongs to “space archaeology”, an emerging field which complements SETI.
Chemical pollutants – whether natural or man-made – are an ever-present and persistent presence in our environment, with long- and short-term adverse health impacts on people and other living things alike. When inhaled directly or ingested via food sources they may cause localized effects in skin tissue or stomach acid production or systemic effects when taken internally via bloodstream absorption; other harmful side effects include carcinogenicity, teratogenicity or mutation.
Scientists believe the widespread presence of chemical pollutants polluting Earth’s air, soil and water over the past decade has exceeded what scientists call “planetary boundaries.” An international panel defined these thresholds in 2016, including global warming, biodiversity loss, excessive nitrogen and phosphorus pollution and plastics contamination. With giant telescopes like Giant Magellan Telescope and European Extremely Large Telescope being built now to detect such signature gases in planetary atmospheres – scientists may soon be able to track any negative changes before they become catastrophic events.
Artificial Light or Heat
Astronomers use extremely large telescopes, including radio wavelengths and light waves, to look for alien signals. Smaller, more portable telescopes may also be used to collect light or radio waves from various places around the globe. Non-scientists can assist astronomers by using SETI@home to analyze all of this data produced by these telescopes on their home computers.
Astronomers use tools such as NASA’s James Webb Space Telescope to search for chemical pollutants that only living organisms could create on distant planets, using tools like its James Webb Space Telescope.
Astronomers are on the lookout for signs that megastructures may exist around stars, which might block some of their light and cause gradual dimming over time. Telescopes like Chile’s Giant Magellan Telescope and Europe’s European Extremely Large Telescope that will open soon are designed to detect such signals.
Astronomers have yet to detect signs of life from any of these various technologies, but that doesn’t mean we’ve given up. NASA’s Curiosity rover’s discovery of freshwater lakes on Mars in 2012 helped kick-start our search for life, while Avi Loeb recently initiated his Galileo Initiative project which seeks to examine life as advanced technological civilizations.
