In 2025, we may detect the first signs of life outside our solar system.
This is critical to potential success 6.5 meter diameter James Webb Space Telescope ,JWSTLaunching in 2021 on an Ariane-5 rocket from Kourou, a coastal city in French Guiana, JWST is our largest space telescope to date. Since it began collecting data, this telescope has allowed astronomers to observe some of the faintest objects in the universe, such as ancient galaxies and black holes.
Perhaps more importantly, in 2022, the telescope also provided us with the first glimpse of a rocky exoplanet in what astronomers call the habitable zone. This is the region around a star where the temperature is just right for liquid water to exist in the planet's rocky surface – one of the key ingredients of life as we know it. These Earth-sized planets were found orbiting a small red star called Trappist-1A star 40 light years away with one tenth the mass of the Sun. Red stars are cooler and smaller than our yellow sun, making it easier to detect Earth-sized planets orbiting around them. Nevertheless, the signal detected from the exoplanet is usually weaker than the signal emitted by the more luminous host star. Discovering these planets was an extremely difficult technical achievement.
The next step—detecting molecules in planetary atmospheres—will be an even more challenging astronomical feat. Whenever a planet passes between us and its star – when it transits – the star's light is filtered by the planet's atmosphere and hits molecules in its path, creating the spectral absorption features that we detect. Can. These characteristics are very difficult to identify. To accomplish this, JWST will need to collect enough data from transits of multiple planets to suppress the signal from the host star and enhance the molecular characteristics of the rocky exoplanet's incredibly thin atmosphere (if you scale these planets down to size). For example, an apple, at that scale its atmosphere would be thinner than the peel of the fruit). However, with powerful space telescopes like JWST, 2025 may be the year we can finally detect these molecular signatures.
However, TRAPPIST-1's detection of water in exoplanets is not our only chance of finding life in distant exoplanets. For example, in 2024, JWST also revealed possible signs of carbon dioxide and methane in the atmosphere K2-18BA planet located at a distance of 124 light years from Earth. However, K2-18b is not a rocky, Earth-like planet orbiting its star in the habitable zone. Instead, it is more likely to be a giant gas sphere with a water ocean similar to Neptune's (albeit smaller in size). This means that if there is life on K2-18b, it may be in a completely different form from life as we know it on Earth.
In 2025, JWST will likely shed more light on these intriguing discoveries, and hopefully confirm for the first time whether there is life on alien worlds light-years away from us.