Readers ask about Mars dust storms, Fermi bubbles and more
Mars dust up Predicting dust storms on Mars will help keep rovers and future astronauts safe on the planet’s surface, Lisa Grossman reported in “How upcoming missions to Mars will help predict its wild dust storms” (SN: 7/4/20 & 7/18/20, p. 24). The story reported that scientists struggle to understand how dust gets lifted into the air. “Have they considered static electricity? A static charge on the dust particles would create repulsion between separate particles and between particles and the ground, levitating them enough to be moved by the winds,” reader Bruce Merchant wrote. Yes, electric fields formed by colliding dust grains can help increase the amount of dust in the atmosphere. Though electric forces alone are not enough to explain dust lift on Mars, the forces “are critical in the dust-lifting process and should be taken into account,” says Germán Martínez of the Lunar and Planetary Institute in Houston. Electric forces also...