Astronomers proposed a new model to determine the possible existence of a liquid subsurface ocean on the icy aktywno. In an article published in Astronomy & Astrophysics, the researchers propose to consider not only the flow of heat emanating from the parent star, but also the influence of tidal forces of the planet and the mass of ecolony. Their model, the researchers checked on the satellites of the gas giants of the Solar system, and constructed predictions for Rhea — second largest moon of Saturn.
Aktywny cause researchers ‘ interest, since they are hypothetically possible life, even if the planet itself is completely unusable. For example, in the Solar system on some satellites of Jupiter and Saturn is awash in liquid subsurface oceans that are protected from cosmic radiation and asteroids thick layer of ice and can be warm enough, that there existed primitive organisms. Although astronomers today is not known any ecolony, partly due to the difficulty in capturing the signals from such a small celestial bodies, there are several candidates, which may be satellites of distant planets.
Astronomers under the leadership of Jesper Tua (Jesper Tjoa) from the University of Groningen has created a model that allows to determine under what conditions on assalone will be able to exist a subsurface ocean. In it the researchers took into account not only the proximity of the satellites to the parent star, but also a variety of factors, including the mass of the planet reflected from its surface radiation, distance to the planet and the impact of tidal forces. In total, scientists have identified the eight most important parameters, with which they tried to determine whether there will be on aktolun the ocean, and if so, at what depth.
The model was tested on several icy moons in the Solar system: Enceladus, Rhea, Titania and Oberon. According to the model, on Enceladus, the sixth largest moon of Saturn, must be the ocean at a depth of 3.6 kilometers, which is at variance with the usual estimates of 10-30 kilometers. However, the researchers note that their model assumes that aktolun is spherically symmetric and does not take into account kriovulkanizma activity that affects the end result. In the case of Titania and Oberon ocean will be located much deeper, at about 150 kilometers below the surface, but the ray was too small and distant Saturn to exist hidden in the water mass.
Astronomers hope that in the future with their models to assess the probability of the existence of oceans on aktywno. They hope to add to our model the best way to study the behavior of thermal conductivity of ice under vacuum conditions and other important properties aktolun and comparison of predictions with empirical data.
Candidate first potential aktywny was opened in summer of 2017. It revolves around the planet Kepler-b 1625 approximately 4000 light years from Earth. However, a few years later, astronomers from Harvard have questioned his existence. When they tried to reproduce the work of their colleagues, they failed, and no one could explain what caused the difference in results.