Parker Solar Probe reaches first perihelion in speedy flyby of the Sun

Parker Solar Probe’s speed, position and round-trip light time as of Oct. 31. Image via NASAAt 1:04 PM ET last night, NASA's Parker Solar Probe reached its first perihelion -- the closest approach to the Sun in its orbit -- of the mission at a distance of about 15 million miles from the Sun's surface. That beats the old record set by the German-American Helios 2 spacecraft in 1976 when it passed about 26.55 million miles from the Sun. Parker also broke the speed record as the fastest spacecraft traveling relative to the Sun last week when it hit a speed estimated at 213,200 miles per hour. Parker will continue to orbit closer and closer to the Sun and will eventually reach a top speed of close to 430,000 miles per hour in 2024, with a distance from the solar surface of only 3.83 million miles. Although that 430,000 miles per hour sounds fast -- and it is compared to everything else humanity has invented -- it's "only" 119.4 miles per second, or just .064 percent of the speed of light (roughly 186,000 miles per second).The primary mission of the Parker Solar Probe is to measure the properties of material in the Sun's outer atmosphere. The observations will help scientists begin to answer the question of why the Sun's atmosphere (the corona) is much hotter than the surface of the sun, as well as how the Sun ejects particles and solar matter into space at such high speeds.