The quest for exomoons, or natural satellites orbiting planets outside our solar system, has been fraught with challenges and controversies. Recently, a new algorithm called Pandora has cast doubt on the existence of two exomoons that were previously claimed to be detected around the exoplanets Kepler-1625b and Kepler-1708b.
The original claims of exomoons were based on observations from NASA’s Kepler space telescope and the Hubble Space Telescope, detecting what seemed to be signs of giant moons that, if existing, would have surpassed all known moons in our solar system . However, a study published in Nature Astronomy by scientists from the Max Planck Institute for Solar System Research (MPS) and the Sonnenberg Observatory suggests a shift toward “planet-only” interpretations of the data, challenging the idea that two of the over 5,300 known exoplanets possess moons .
The study’s lead author, Dr. Rene Heller, expressed disappointment in the results, stating, “We would have liked to confirm the discovery of exomoons around Kepler-1625b and Kepler-1708b, but unfortunately, our analyses show otherwise.” The study’s findings underscore the complexities of detecting such distant objects, often much smaller than their host planets and obscured by various interstellar factors.
The new algorithm Pandora is designed to analyze the light curves of exoplanets, or the changes in brightness as they transit across their host stars. By comparing different models of how the light curves could be affected by various factors, such as stellar activity, instrumental noise, or planetary companions, Pandora can determine the most likely scenario that explains the data. In the case of Kepler-1625b and Kepler-1708b, Pandora found that the presence of exomoons was not necessary to account for the observed light curves, and that simpler models without moons were more plausible.
The debate over exomoons is not over yet, as the original discoverers of the potential moons have defended their findings in a preprint paper . They argue that Pandora’s analysis is too simplistic and does not account for all the possible sources of uncertainty in the data. They also point out that Pandora’s results are not conclusive and still leave some room for exomoons to exist.
The search for exomoons is important for understanding the diversity and evolution of planetary systems beyond our own. Exomoons could also have implications for the habitability and detection of life on other worlds. For example, some exomoons could be large enough to retain atmospheres and liquid water on their surfaces . Exomoons could also affect the climate and stability of their host planets by exerting tidal forces or shielding them from stellar radiation .
As more data and methods become available, astronomers hope to resolve the mystery of exomoons and explore their fascinating properties. Until then, the debate between team pro-exomoon and team no-exomoon will continue to spark interest and curiosity among scientists and the public alike.