Produced by: Tarun Mishra Designed by: Manoj Kumar
Scientists, utilizing data from NASA's retired Kepler Space Telescope, have made a groundbreaking study to unravel the perplexing phenomenon of certain exoplanets diminishing in size.
More than 5000 Exoplanets have been discovered so far by humans in the Universe. Exoplanets are celestial bodies discovered beyond our solar system. The research, led by Jessie Christiansen from Caltech/IPAC and published in Astronomical Journal, concentrated on understanding the intricate dynamics leading to the reduction in size of specific sub-Neptune planets.
Astronomers have long observed a peculiar "size gap" between rocky super-Earths and gaseous sub-Neptunes. This study also focused on exploring why planets with diameters between 1.5 and 2 times that of Earth are notably scarce.
Christiansen's team suggested a compelling link between the cores of select sub-Neptune planets and the gradual shrinking of their atmospheres, providing a crucial clue to the cosmic puzzle.
The study proposes that sub-Neptunes lacking sufficient mass may experience weakened gravitational pull, causing the loss of their atmospheres and resulting in a reduction in size.
Two primary mechanisms for atmospheric loss are examined—core-powered mass loss and photoevaporation. The study aligned with the theory of core-powered mass loss, where a planet's hot core gradually expels the atmosphere.
Photoevaporation occurs when a star's intense radiation strips away a planet's atmosphere. Core-powered mass loss is projected to occur approximately around the 1 billion-year mark in a planet's existence.
The research team meticulously analyses data from the K2 mission, concentrating on star clusters Praesepe and Hyades. Their findings indicate that sub-Neptune planets in these clusters have not undergone photoevaporation, pointing toward core-powered mass loss as the probable cause.
The study's implications extend beyond solving a cosmic puzzle. Understanding the evolution of exoplanet atmospheres offers valuable insights into the potential habitability of distant worlds, providing a deeper connection between cosmic phenomena and the search for life beyond Earth.
As Christiansen emphasized, the research is an ongoing journey, with future studies are poised to rigorously test and refine these theories, promising an enhanced understanding of the intricate mechanisms governing exoplanetary evolution.