NASA’s Parker Solar Probe spacecraft has survived its final flyby of the Sun, equaling its own record by coming within just 4.5 million miles (7.26 million kilometers) of the solar surface.
That’s a little less than 5 percent of the Earth-Sun distance, which totals about 93 million miles (150 million kilometers). For comparison, Mercury, the closest planet to the Sun, is 23 million miles (37 million kilometers) from the Sun.
Landmark
Launched in 2018, and on its 20th close pass of the sun, the car-sized spacecraft reached its closest point — called perihelion — at 11:47 p.m. EDT on June 29, NASA reported in a blog post after the spacecraft reported to the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. When it reached that milestone point, it was traveling at 394,736 miles (635,266 kilometers) per hour, faster than ever before. Its final encounter with the sun will occur between June 25 and July 5.
This 20th close encounter with the sun won’t be the probe’s last, but there aren’t many more left in its mission. Its 21st close encounter will occur on Sept. 30, followed by its 22nd on Dec. 24, its 23rd on March 22, and its 24th on June 19. That 24th perihelion will bring the spacecraft just 3.8 million miles from the sun as it moves at 430,000 miles (692,017 kilometers) per hour.
Outer corona
The main mission of the Parker Solar Probe is to study the outer corona of the Sun and understand the solar wind and its impact on the solar system. It will help scientists find the source of the high-energy particles from the Sun that form the solar wind, which dominates the entire solar system.
Increasing knowledge of the solar wind will help scientists determine where the edge of the solar system actually is, but on a more practical level it will help us predict space weather more accurately. Space weather can cause radio blackouts, damage satellites, harm astronauts, and disrupt power grids. It also produces spectacular displays of the aurora borealis, also known as the Northern Lights and the Southern Lights.
Powerful eruption
Last September, the Parker Solar Probe became the first spacecraft ever to fly through a coronal mass ejection from the sun. A CME is a powerful eruption of billions of tons of plasma from the sun’s surface, typically seen in the wake of a solar flare. When aimed at Earth, a CME can trigger a geomagnetic storm, often resulting in spectacular displays of the aurora borealis.
NASA is currently in the midst of Heliophysics Big Year, a celebration of solar science and the sun’s influence on Earth and the rest of the solar system. It began with the Oct. 14 annular solar eclipse, which swept across nine U.S. states, and will end with the Parker Solar Probe’s closest approach to the sun in December 2024.
I wish you clear skies and big eyes.
Pick up my books Stargazing in 2024, A stargazing program for beginnersAnd When is the next solar eclipse?