Explore the search for extraterrestrial life through the lens of astrobiology.
For centuries, the idea of life beyond Earth has captivated human imagination. From science fiction stories to philosophical debates, the possibility that we are not alone in the universe has driven curiosity and scientific inquiry. Today, the search for extraterrestrial life has evolved into a serious scientific endeavour, with astrobiology emerging as the field dedicated to exploring the conditions under which life might exist elsewhere in the cosmos. Read on to know more!
Astrobiology is the scientific study of life in the universe, including its origins, evolution, and potential existence on other planets. The field draws from biology, chemistry, astronomy, and geology to understand the conditions necessary for life and where those conditions might be met beyond Earth.
To search for life elsewhere, astrobiologists begin by studying life on Earth—how it originated and what conditions allow it to thrive. By examining extremophiles—organisms that live in extreme environments such as deep-sea vents, acidic lakes, or polar ice caps—scientists gain insights into how life could survive in harsh conditions on other planets or moons.
Mars has long been a central focus in the search for extraterrestrial life due to its proximity to Earth and its historical potential to have once harboured water. Recent missions to Mars, such as NASA’s Perseverance rover, have provided valuable data about the planet’s geology and climate, fuelling hope that microbial life may have existed there in the past or could still exist beneath the surface.
One of the most compelling reasons Mars is considered a candidate for life is the evidence of ancient water. Rivers, lakes, and possibly even oceans once covered the Martian surface. The discovery of subsurface water ice and the possibility of briny liquid water beneath the surface have intensified interest in Mars as a target for Astro biological exploration.
NASA's Perseverance rover is equipped with sophisticated instruments designed to detect biosignatures—chemical or physical signs that could indicate past or present life. The rover is currently exploring the Jezero Crater, an ancient lakebed that may have been home to microbial life. Future missions, including those by the European Space Agency, aim to return Martian samples to Earth for further analysis.
Europa is covered in a thick layer of ice, but beneath this surface lies a vast ocean of liquid water. NASA’s upcoming Europa Clipper mission, scheduled to launch in the mid-2020s, aims to study the moon’s icy shell and subsurface ocean. Scientists hope that Europa’s Ocean, possibly warmed by hydrothermal vents on the seafloor, could provide the right conditions for life similar to Earth’s deep-sea ecosystems.
Saturn's moon Enceladus also boasts an underground ocean, and it has captured the interest of astrobiologists thanks to the discovery of water plumes shooting out from its surface. These plumes contain organic compounds, raising the possibility that Enceladus’ Ocean could harbour microbial life. Future missions may focus on sampling these plumes directly to search for signs of life.
The search for extraterrestrial life represents one of humanity’s most ambitious endeavours. From studying the harsh conditions of Mars and icy moons to exploring distant exoplanets, astrobiology is pushing the boundaries of what we know about life and its potential to exist beyond Earth.
