Astronomers have confirmed a fifth, potentially habitable planet in the nearby L 98-59 system, located just 35 light-years away, with conditions that may support liquid water, making it a prime target for future atmospheric studies.
Scientists propose the existence of an Earth-like planet in our solar system, located closer than the disputed Planet Nine. This hypothetical planet, with a mass between 1.5 and 3 times that of Earth, could explain the clustering behaviors observed among trans-Neptunian objects (TNOs) in the Kuiper Belt. The planet's gravity would push TNOs into clustered populations beyond 150 astronomical units, providing testable signatures for its existence. Further observations and improved techniques could reveal or rule out the presence of this hidden world, offering new insights into planet formation and dynamics in the outer solar system.