The Planet Mercury - Facts and Photos. Mercury - the closest of all planets to the Sun. At first glance Mercury resembles nothing more closely than our own Moon - a barren rocky world strewn with craters. #Mercury is the planet closest to the Sun, but not the hottest. Find out which planet is: http://astronomyisawesome.com/solar-systems/cool-facts-about-mercury/ #astronomy
Earth's magnetic field, which protects the planet from harmful blasts of solar radiation, is much older than scientists had previously thought. This invisible, protective shield likely existed shortly after the planet formed; a finding that could shed light on why Earth is habitable and Mars is not. Earth's magnetic field helped make life on the planet possible. Without our magnetic field, solar winds would strip away the planet's atmosphere and oceans.