Fig. 13.From: Variability of solar/stellar activity and magnetic field and its influence on planetary atmosphere evolutionLeft side illustrates the size relation of exoplanets around the two M-stars EV Lacertae and Proxima Centauri with a transiting Earth analogue with an extended hydrogen atmosphere of 7REarth. Right side shows a preliminary model simulation of an extended hydrogen corona and stellar wind produced hydrogen ENAs around an Earth-size planet with an expanded hydrogen-rich thermosphere of 7REarth (Lammer et al., 2011b).Back to article page