NASA Confirms Discovery of TOI-1846 b, a Potential Ocean-Bearing Super-Earth

NASA has officially confirmed the discovery of TOI-1846 b, a nearby super-Earth that may harbor water. The planet, located approximately 154 light-years away in the northern constellation Lyra, was first detected by NASA's Transiting Exoplanet Survey Satellite (TESS) in March 2025. The announcement comes from a collaborative effort led by Abderahmane Soubkiou of the Oukaimeden Observatory in Morocco, in conjunction with astronomers from around the world.

The TESS mission, launched on April 18, 2018, is designed to identify exoplanets by measuring the minute dimming of stars as planets transit in front of them. TOI-1846 b is classified as a super-Earth, nearly twice the size of Earth and approximately four times its mass, positioning it in a unique category of exoplanets that lie between rocky planets and gas giants. These characteristics suggest that TOI-1846 b may possess a layer of dense ice beneath a thin atmosphere or even a shallow ocean, despite its estimated surface temperature hovering around 600°F due to its proximity to its host star.

According to Soubkiou, "We have validated TOI-1846 b using TESS and multicolor ground-based photometric data, high-resolution imaging, and spectroscopic observations". The planet orbits its star, a red dwarf roughly 40% the size and mass of the Sun, in less than four days, much closer than Mercury's orbit around our Sun. This close proximity raises intriguing questions about the planet's atmospheric retention and the potential for water to exist in liquid form.

The discovery of TOI-1846 b is significant as it sits in a region of space that has been relatively under-sampled in terms of exoplanetary observations, particularly around M dwarf stars. Red dwarfs constitute about 75% of the stars in our galaxy and are critical in the search for habitable worlds, given their cooler temperatures and frequent transiting planets.

Dr. Emily Carter, an astrophysicist at the California Institute of Technology, emphasizes the importance of TOI-1846 b in understanding planetary formation. "The density and characteristics of TOI-1846 b provide insights into the processes that lead to the formation of planets within this size range, especially in the context of the radius valley observed in exoplanet surveys," she stated. This valley represents a gap in the distribution of exoplanets based on their radii, which can inform theories regarding planetary atmospheres and composition.

Future observations of TOI-1846 b will include radial velocity measurements using the MAROON-X instrument located at Gemini North in Hawaii. This technology will allow scientists to gauge the planet’s mass and investigate the possibility of additional planets within its system. Additionally, the upcoming James Webb Space Telescope (JWST) Cycle 4 may provide opportunities to analyze the planet’s atmospheric composition by detecting specific gases like water vapor or carbon dioxide.

In conclusion, the discovery of TOI-1846 b offers a promising avenue for further exploration of exoplanets and their potential to host life. As researchers continue to study this super-Earth, it will contribute to a broader understanding of the conditions that may allow for liquid water to persist, even in extreme environments. The ongoing efforts to catalog and analyze exoplanets like TOI-1846 b are crucial for identifying Earth-like worlds that orbit red dwarfs, potentially leading to significant revelations in the search for extraterrestrial life.

The study detailing the findings on TOI-1846 b has been published in arXiv and marks a notable advancement in the field of exoplanet research.