Welcome to the strange new worlds of the Exoplanet Era. A new category of exoplanets, known as eggshell planets, have ultra-thin, brittle crusts only one kilometer in depth, too thin to sustain tectonics and will be hostile to life. Meanwhile, Earth and Mars are crusty down to depths of 40 and 100 km according … Continue reading Strange ‘Eggshell’ Planets Orbiting Distant Stars –Too Thin to Sustain Plate Tectonics and Life