Many extrasolar planets of terrestrial type can resemble the structure of the icy satellites of the giant planets of the Solar system and still be volcanically active. To such conclusion came the scientists of NASA, calculating the internal heat levels for 53 exoplanets. The article is published in Publications of the Astronomical Society of the Pacific.
It is believed that volcanic activity contributes to the formation of atmosphere on earth-like exoplanets, but the absence of volcanism or irregular eruptions interfere with this process. Therefore, on geologically active planets are more likely to form a potentially habitable environment. From this point of view is interesting and cryovolcanism on cold planets, because it confirms the presence of oceans under their icy surface — we’ve seen things on some satellites of the giant planets of the Solar system — for example, on Jupiter’s moon Europe.
University of California researchers over a decade ago built a model of levels of volcanism depending on the weight and age of the planet for earth-like planets with a mass from 0.25 to 25 earth. However, this analysis did not take into account the influence on volcanic activity and tidal forces.
A NASA planetary scientist Lynn quick (Lynnae Quick) and her colleagues from the Arizona Institute of planetology and the University of Idaho has calculated the level of internal heat for 53 exoplanet mass from 0,086 to 8 Earth masses and a radius of 0.54 to 2 radii of our planet. Scientists assumed that the heat sources for such planets are as the decay of radioactive elements in their depths, and tidal interaction. Based on the levels of the internal heat of the planets of the Solar system and their satellites, planetary scientists were able to predict the level of volcanic activity on extrasolar planets. The majority of exoplanets in the sample had a radius of about 1.7 Earth’s radius, which clearly allowed them to refer to the supersense.
The calculations showed that all studied exoplanets are likely volcanically active. Effective temperature and density of the planets 14 — almost 26 percent of the sample suggests that these bodies are probably covered with oceans. Nine of these 14 planets does need to resemble the structure of selected icy satellites of Jupiter and Saturn — the oceans they are hidden by the surface ice layer, and therefore, there is cryovolcanism. Quick and her colleagues believe that this may be indirect evidence of the potential habitability of such planets, and hence, spectral studies and study of the potential volcanic activity of earth-like exoplanets should be a priority for research in the coming
Earlier we wrote about how the ESPRESSO spectrograph confirmed the existence of earth-like exoplanets b Proxima the nearest star to the Sun, and also about how sun-like star found exoplanet’s size and mass similar to Earth.