Parker Solar Probe, the fastest spacecraft ever that will skirt the surface of the sun, lifts off from Cape Canaveral this weekend.
One of the greatest mysteries of the sun is the extraordinary temperature of its corona. This mass of plasma stretches millions of miles outward from the solar surface, as if it were the sun’s atmosphere. Somehow, it’s heated to millions of degrees Kelvin, much higher than the sun’s surface (called the photosphere), which burns at a comparatively balmy 6,000 degrees K.
Read more at Popular Mechanics