Astronomers have shifted their focus from the question of whether there is life elsewhere in the Universe to a more pressing one: when will we find it? Many experts are optimistic about the prospects of detecting signs of extraterrestrial life on distant planets, possibly within the next few years.
Leading a mission to Jupiter, one scientist even suggests that it would be “surprising” if there were no signs of life on one of the planet’s icy moons.
The recent detection of potential life-related signals by NASA’s James Webb Space Telescope (JWST) on a planet outside our Solar System has fueled this optimism. Moreover, numerous missions either underway or in the planning stages are indicative of a burgeoning space race for the most significant scientific discovery in history.
Professor Catherine Heymans, Scotland’s Astronomer Royal, points out that with the technology at our disposal, we can now address the question of whether we are alone in the cosmos. Telescopes can analyze the atmospheres of distant planets, searching for chemical markers that, on Earth, are produced by living organisms.
A significant development occurred when researchers detected a gas in the atmosphere of a planet named K2-18b, located 120 light years away. This gas hinting at simple marine organisms was found within the “Goldilocks zone” – the region where conditions are just right for liquid water to exist, a critical factor for life.
The team expects to confirm or dispel these tantalizing hints within a year. Professor Nikku Madhusudhan from the Institute of Astronomy at Cambridge University, who led the study, believes that such a discovery would revolutionize our understanding of life’s prevalence in the Universe. He predicts that within five years, our comprehension of extraterrestrial life will undergo a profound transformation.
Even if K2-18b yields no signs of life, the research team has a list of ten more Goldilocks planets to study and potentially more beyond that. A lack of findings would still provide valuable insights into the potential for life on such planets.
These exciting prospects have prompted the development of advanced instruments, such as the Habitable Worlds Observatory (HWO), scheduled for the 2030s. It employs a high-tech sunshield to minimize starlight interference, enabling the examination of the atmospheres of Earth-like planets. The Extremely Large Telescope (ELT), set to come online later this decade, has a colossal 39-meter mirror, which promises detailed analysis of planetary atmospheres.
While some focus on distant planets, others are directing their attention closer to home, specifically our Solar System’s planets. Icy moons like Europa, one of Jupiter’s satellites, hold promise as potential habitats for life. Europa has an ocean beneath its icy surface, with plumes of water vapor venting into space. Both NASA’s Clipper and the European Space Agency’s Jupiter Icy Moons Explorer (Juice) missions plan to explore Europa in the early 2030s.
Nasa’s Dragonfly spacecraft is headed to Titan, one of Saturn’s moons, where exotic features like lakes and carbon-rich chemicals suggest conditions conducive to life.
Mars, although inhospitable today, may have once supported life. NASA’s Perseverance rover is collecting samples from a crater that was once a river delta, and a future mission will return these rocks to Earth for analysis, searching for ancient microfossils.
The Search for Extraterrestrial Intelligence (Seti) Institute is another player in the quest for alien life. Advanced telescopes like JWST help Seti narrow down the search by identifying promising locations for extraterrestrial civilizations. Dr. Nathalie Cabrol, director of Seti’s Carl Sagan Center for the Study of Life in the Universe, highlights that a signal from an alien civilization, while considered a long shot by some, would provide an unambiguous indicator of life.
With the discovery of over 5,000 planets orbiting other stars, astronomers and astrobiologists have an unprecedented opportunity to study these distant worlds in detail. As Dr. Subhajit Sarker of Cardiff University notes, the potential discovery of extraterrestrial life would not only be a scientific revolution but also a transformative moment in humanity’s perception of its place in the Universe.