Astronomers may have discovered the most Earth-like planet yet outside our solar system. Named Kepler 438b, this exoplanet, located 470 light-years away in the constellation Lyra, shares some significant characteristics with Earth that could make it a potential candidate for hosting life. Orbiting an orange dwarf star, Kepler 438b lies in the “Goldilocks” or habitable zone, where conditions could allow liquid water to exist. This zone is crucial for habitability as it provides a temperature range suitable for sustaining life as we know it. Additionally, Kepler 438b is about 12% larger than Earth, making it more likely to have a rocky composition, with scientists estimating a 70% probability that it is indeed rocky.

Discovered using NASA’s Kepler space telescope, Kepler 438b completes an orbit around its star every 35 days, meaning a year on this exoplanet is nearly 10 times shorter than a year on Earth. With 40% more warmth from its host star, the planet offers a potentially hospitable environment. However, scientists are still unsure if it has an atmosphere, which would be essential in maintaining stable temperatures and supporting life. If Kepler 438b does have an atmosphere, researchers predict an average surface temperature of around 60°C.

The discovery of Kepler 438b and seven other small planets in habitable zones was announced by scientists from the Harvard-Smithsonian Center for Astrophysics at an American Astronomical Society meeting. The Kepler space telescope, which detects planets by monitoring periodic dips in starlight as they pass in front of their stars, played a key role in identifying these planets. This recent discovery doubles the number of known small planets orbiting in habitable zones, many of which are less than twice the size of Earth. One such discovery is Kepler 442b, a planet with a 60% chance of being rocky, though it is larger and farther from its star than Kepler 438b.

To confirm these findings, the Harvard-Smithsonian team used a program called Blender. This program statistically analyzes data to rule out false detections, which can occur when distant stars eclipse each other, mimicking the dimming effect caused by a planet transiting its star. Out of 12 suspected planets, Blender confirmed 11 with a high probability of being real, further solidifying Kepler 438b as a likely Earth-like planet.

While Kepler 438b and similar exoplanets present exciting possibilities, astronomers are eager for next-generation telescopes to provide more detailed observations. These include the James Webb Space Telescope, which will succeed the Hubble Telescope, and the European Extremely Large Telescope, currently under construction in Chile. These advanced instruments will allow scientists to analyze the atmospheres of distant planets and search for possible signs of life. Additionally, scientists are examining indirect signs of habitability, such as potential moons and nearby gas giants like Jupiter, which may help stabilize a planet’s environment by deflecting asteroid impacts.

Kepler 438b stands as one of the most promising candidates for an Earth-like planet beyond our solar system, marking an exciting step toward understanding the potential for life elsewhere in the universe.