Exoplanets are planets located outside our Solar System. Their discovery has deeply transformed our understanding of the Universe, revealing that planetary systems are far more common than we ever imagined. Each new detection opens a window to worlds that are sometimes very different from Earth, and sometimes surprisingly familiar.
Most exoplanets are discovered by observing variations in the brightness of stars. When a planet passes in front of its star, it slightly dims its light: this is the transit method. Other techniques, such as measuring the star's oscillations or direct imaging, allow us to estimate the mass, size, orbit, or even the atmospheric composition of these distant worlds.
With billions of stars in the Milky Way, the search for exoplanets seems endless. One of the current major challenges is to identify biosignatures: chemical or physical clues that could reveal the presence of life. Oxygen, methane, water vapor, seasonal variations, or atmospheric imbalances are all leads being studied to detect potentially habitable environments.
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Exoplanet Overview: Candidates and Confirmed 
Gliese 581 g: A Serious Candidate for Habitability 
Discovery of solid buckyballs 
Kepler-22b: First Habitable Exoplanet Discovered in the Temperate Zone 
Exoplanets: Techniques and Discoveries 
Cheops, characteristics of exoplanets 
Mini-Neptunes: A Fascinating Class of Extrasolar Planets 
Turn Off the Stars to Detect Life! 
The New Promised Lands: Top Candidates for Habitability 
JWST, the end of the dark ages 
The Milky Way: A Galaxy Teeming with Habitable Worlds 
HD 100546 b: A Giant Exoplanet Forming in an Extended Habitable Zone 
Super-Earths: Habitable Planets in Sight? 
The habitable zone of the Kepler-186 system 
Rogue Exoplanets: Lost Worlds in the Cosmic Darkness 
55 Cancri e, the diamond planet 
Number of candidate and confirmed exoplanets 
Trappist or the harmony of the cosmos