By Jim Leffman
A probe has flown the closest yet to the Sun’s surface on a mission to unlock the secrets of the star.
At the end of June, NASA’s Parker Solar Probe came within 5.3 million miles of the solar surface, where temperatures reach more than 10,000 degrees Celsius (18,032 degrees Fahrenheit).
It is the probe’s 16th orbit of the Sun, and it emerged unscathed while traveling 364,610 miles per hour, the equivalent of London to Edinburgh in just over three seconds.
At the closest planned approach of 3.8 million miles, Parker Solar Probe will hit speeds of approximately 430,000 mph (700,000 kph).
Its solar shield faces temperatures approaching 1,377 C (2,500 F), although its payload will be near room temperature.
It will be more than seven times closer than the previous record-holder for a close solar pass, the Helios 2 spacecraft, which came within 27 million miles in 1976, and about a tenth as close as Mercury, which is, on average, about 36 million miles from the Sun.
The primary science goals for the mission are to trace how energy and heat move through the solar corona and explore what accelerates the solar wind as well as solar energetic particles.
Scientists have sought these answers for more than 60 years, but the investigation requires sending a probe right through the 1377 degrees centigrade heat of the corona.
Today, this is finally possible with cutting-edge thermal engineering advances that protect the mission on its dangerous journey.
A 4.5-inch-thick (11.43 cm) carbon-composite shield protects the spacecraft and instruments from the Sun’s heat.
The spacecraft will fly close enough to the Sun to watch the solar wind speed up from subsonic to supersonic, and it will pass through the birthplace of the highest-energy solar particles.
Parker Solar Probe carries four instrument suites designed to study magnetic fields, plasma, and energetic particles, and image the solar wind.
Following its latest orbit, or perihelion, the Probe will swing past Venus for its sixth flyby of the planet.
The mission team at the Johns Hopkins Applied Physics Laboratory (APL) applied a small trajectory correction maneuver on June 7, 2023, the first-course correction since March 2022.
This flyby will be the sixth of seven planned flybys of Venus during Parker’s primary mission.
Parker uses Venus’ gravity to tighten its orbit around the Sun and set up the next perihelion at just 4.5 million miles from the Sun’s surface.
As the Sun becomes increasingly active, this perihelion will be especially important to learn more about heliophysics.
The Parker Solar Probe was developed as part of NASA’s Living With a Star program to explore aspects of the Sun-Earth system that directly affect life and society.
Produced in association with SWNS Talker
Edited by Judy Marie Sansom and Sterling Creighton Beard