The Parker Solar Probe is now flying through the Sun's outer atmosphere at 430,000 miles per hour, fast enough to cross the continental United States in 20 seconds, and its heat shield protects the instruments behind it by keeping them at room temperature

The Parker Solar Probe is now flying through the Sun's outer atmosphere at 430,000 miles per hour, fast enough to cross the continental United States in 20 seconds, and its heat shield protects the instruments behind it by keeping them at room temperature

On the front of the Parker Solar Probe, a slab of carbon foam four and a half inches thick is glowing at around 2,500 degrees Fahrenheit. Less than a meter behind it, the science instruments sit at roughly room temperature, taking measurements as if they were in a laboratory in Maryland. That gap, between a face hot enough to soften steel and a payload bay cool enough to touch, is the central trick of the entire mission. It is also the reason a …