NASA’s Parker Solar Probe Completes 18th Close Approach to the Sun

NASA’s Parker Solar Probe completed its 18th close approach to the Sun on Dec. 28, 2023, matching its own distance record by skimming just about 4.51 million miles (7.26 million kilometers) from the solar surface.

The close approach (known as perihelion) occurred at 7:56 p.m. EST, with Parker Solar Probe traveling at 394,736 miles per hour (635,266 kilometers per hour) around the Sun – also matching the speed record for the 17th solar encounter. The milestone also marked the midway point in the mission’s 18th solar encounter, which began Dec. 24, 2023, and continued through Jan. 2, 2024. 

An illustration of Parker Solar Probe's orbit shows the spacecraft's eighteenth solar encounter on Dec. 28, 2023, at 4.51 million miles from the Sun.
Parker Solar Probe’s 18th orbit included a perihelion that brought the spacecraft within 4.51 million miles of the Sun. Credit: NASA/Johns Hopkins APL/Steve Gribben

The spacecraft entered the encounter in good health, with all systems operating normally. Parker Solar Probe checked back in with mission operators at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland – where the spacecraft was also designed and built – by sending a status beacon tone on Jan. 5.

By Michael Buckley
Johns Hopkins Applied Physics Laboratory