Parker Solar Probe has made its 18th close approach to the sun, setting distance and speed records and marking an important milestone in its ongoing mission. NASA's Parker Solar Probe completed its 18th close approach to the sun on December 28, 2023, passing about 4.51 million miles (7.26 million kilometers) from the sun's surface, setting a new distance record for itself.

On December 28, 2023, NASA's Parker Solar Probe successfully completed its 18th mission close to the sun. Its distance and speed both broke previous records, and its health status was fed back to the mission control center. Image source: NASAGSFC/CIL/BrianMonroe

The close approach, known as perihelion, occurred at 7:56 p.m. EDT and sent the Parker Solar Probe orbiting the sun at 394,736 miles per hour (635,266 kilometers per hour) - tying the record for the 17th encounter with the sun. This milestone also marks the midpoint of the 18th Solar Survey mission, which will begin on December 24, 2023, and continue until January 2, 2024.

Parker Solar Probe's 18th orbit included a perihelion, which brought the spacecraft 4.51 million miles from the sun. Image source: NASA/JohnsHopkinsAPL/SteveGribben

The spacecraft entered the rendezvous point in good health and all systems were operating normally. Parker Solar Probe sent a status beacon tone on January 5 to mission operators at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, to report the situation.

Illustration of the Parker Solar Probe approaching the Sun. Image source: Johns Hopkins University Applied Physics Laboratory

NASA's Parker Solar Probe is a groundbreaking mission in solar science, launched on August 12, 2018, with the primary goal of studying the Sun more closely and in more detail than any spacecraft before it. The mission, named for Eugene Parker, the solar physicist who proposed the existence of the solar wind, marks an important milestone in human exploration to understand our nearest star.

The Parker Solar Probe is designed to withstand the extreme heat and radiation found near the Sun. It uses a revolutionary heat shield that allows the spacecraft to withstand temperatures in excess of 2,500 degrees Fahrenheit while maintaining its instruments at relatively moderate operating temperatures.

The bold probe aims to unravel the mysteries of the sun's corona, the outermost layer of the sun's atmosphere, which is hotter than the sun's surface for reasons that are not fully understood. The Parker Solar Probe's mission also includes studying the solar wind and the mechanisms that accelerate it, as well as energetic particles from the sun, which are critical to understanding space weather and its impact on Earth.

Throughout the mission, the probe made a series of close approaches to the sun, using Venus' gravity to change its orbit and get closer to the sun over time. These close encounters provide unprecedented data and provide a deeper understanding of solar processes that have baffled scientists for decades. The success of the Parker Solar Probe is not only a milestone in solar science, but also a beacon for future exploration of the solar system and beyond.