Parker Solar Probe Perihelion 25 occurred on September 15, 2025, at 20:22 UT. This was the first solar encounter of the extended PSP mission that occurred at the identical closest approach distance (9.86 Rs, or 0.046 AU) with the previous three perihelia (22 - 24). The perihelion itself, and most of the encounter, was on the far side. However, prior to perihelion, Parker roughly co-rotated with the solar West limb and the Parker spiral aligned with Earth for several days down to ~14 solar radii. Two days after perihelion, having passed entirely over the far hemisphere of the Sun, Parker re-emerged over the East limb at around 25 solar radii and similarly co-rotated with sources on the East limb for several days. The East limb at this time was also observed as near disk center by Solar Orbiter during its near-coincident perihelion pass from its vantage point in quadrature with the Earth.
In support of these two limb crossings, Parker footpoint predictions were issued daily from Friday 9/12 until Thursday 9/18, although no on-disk targets were anticipated for the dates of closest approach (9/15 and 9/16).
If you have observational results to share, please contact us at whpi_help@hao.ucar.edu.
Visit the campaign target archive page.
