Recently, NASA has uncovered 17 exoplanets with habitable oceans concealed beneath their ice shells. According to NASA's statement, "Water from these oceans could occasionally erupt as geysers through the ice crust. The science team calculated the amount of geyser activity on these exoplanets for the first time."
Dr Lynnae Quick of NASA's Goddard Space Flight Centre and the study's lead challenged the conventional focus on a star's 'habitable zone' and explored the possibility of hidden oceans on distant and cold exoplanets.
The study was issued in the Astrophysical Journal and focused on the exoplanet's internal heating mechanisms using known properties of our solar system's icy moons, including Europa and Enceladus, which have subsurface oceans due to gravitational forces from their host planets and other moons nearby.
According to Dr Quick, "Our analyses predict that these 17 worlds may have ice-covered surfaces but receive enough internal heating from the decay of radioactive elements and tidal forces from their host stars to maintain internal oceans." He added, "Thanks to the amount of internal heating they experience, all planets in our study could also exhibit cryovolcanic eruptions in the form of geyser-like plumes."
The researchers focused on Earth-sized exoplanets with low density, observing high ice and water content. The estimated surface temperature of the exoplanets indicated colder conditions than the Earth, revealing possibilities of ice coatings, while its particular components remain unknown. The research further estimated complete internal heating using tidal forces and nuclear activity. The team was able to anticipate ice layer thickness and geyser activity on the exoplanets by comparing these statistics to Europa's.
When exoplanets pass in front of their stars, geyser activity can be observed. Water vapour from geysers could obscure specific hues of starlight, indicating cryovolcanic eruptions. Water vapour detections that fluctuate over time might indicate geological activity.
Surface temperatures might be up to 60 degrees Fahrenheit cooler than previously thought. The thickness of the ice shells varied among the exoplanets, ranging from 190 feet to 24 miles. Geyser activity estimates for Kepler 441b varied from 17.6 pounds per second to 13.2 million pounds per second for Proxima Centauri b.
