18 August 2019 - Mission Day: 8661 - DOY: 230
Pick of The Week

SOHO and the Parker Solar Probe Join Forces to study the Sun (November 15, 2017)

Large [TIFF, 12MB]

Exciting new science opportunities are in store during the perihelion passes (the point in an orbit when it is closest to the Sun) of the recently launched Parker Solar Probe (PSP). It will approach the Sun to within 10 solar radii (approximately 6 million km from the surface). For comparison, SOHO's LASCO C3's field-of-view extends to 30 solar radii (21 million km).

The image below shows the PSP science windows when the spacecraft is within 38 million km (0.25 au) from the Sun. The perihelion passes in 2019-2020 and 2021-2022 are shown in red and yellow, respectively and the symbols are one hour apart. SOHO's LASCO observations will be critically important to assess the structures PSP will fly through during its close approaches to the Sun. Thanks to the extremely well-understood performance of LASCO's C2 and C3 telescopes, LASCO will also provide a uniquely reliable way to cross-calibrate the photometry of PSP's heliospheric imager (WISPR).

Joint observations between PSP and SOHO's payload will shed new light on how the Sun connects to Earth and the solar system and the heliosphere. With PSP measuring the nascent solar wind and the onsets and properties of solar particle events close to the Sun, SOHO will provide the near-Earth perspective and allow us to understand how solar wind streams expand and fill the heliosphere. It will also provide a unique view about how solar energetic particles diffuse across the frozen-in interplanetary magnetic field -- a long-standing issue in heliophysics research.

For the first time, scientists will be able to obtain long-awaited, concurrent, close to the Sun and near-Earth observations, which will also help set the stage for ESA's next solar and heliospheric physics mission, Solar Orbiter.


SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.

If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to steele.hill@gsfc.nasa.gov.


• European Site • US Site


Feedback & Comments: SOHO Webmaster

Last modification: January 26, 2018

SOHO is a project of international cooperation between