PUNCH News

Announcing the First Bi-Monthly PUNCH Science Meeting: Come Play in the PUNCH Sandbox!

The solar wind is turbulent. One of PUNCH’s major objectives is to study that turbulent flow. However, obtaining quantitative information about in-situ processes from our images can be challenging. PUNCH images integrate all light along the line of sight between the observer and infinity, so the structure of local turbulence is blurred. We therefore expect its measurements to relate differently from previous in-situ data to the underlying turbulent environment of the outer corona and inner heliosphere. To understand these differences, we mimic the action of PUNCH observation itself (using the FORWARD tool, Gibson+2016), processing “ground truth” magnetohydrodynamic simulations of turbulence to obtain synthetic white-light (PUNCH-like) images. Direct 1-to-1 comparison of the simulation to “PUNCHified” images of the same shows how PUNCH observations change the spatial spectrum of the turbulence. By simple integration (projection) of the simulated densities from 3D to 2D, we can match the PUNCH-specific variation from the more sophisticated FORWARD model images. Compiling a catalog of simulations with different properties that match PUNCH remote observations will be the key to determining the properties of the solar wind simultaneously across the vast PUNCH field of view, yielding coverage impossible to attain with in-situ spacecraft alone. In preparation for these new observations, Associate Investigator Francesco Pecora and colleagues have undertaken the forward analysis described above as Paper 2 of the Solar Physics PUNCH Mission Overview Topical Issue, providing context and guidance for PUNCH as it obtains its brand new view on solar wind turbulence.

PUNCH is about to get a close look at a “point-of-no-return” zone surrounding the Sun. Charged particles fly away from the Sun in the form of the steady solar wind and bursty coronal mass ejections (CMEs), and most of those particles escape all the way out past the planets of our solar system. Sometimes, though, particles fall back down, but only if they're below the Sun's Alfvén surface --- named after Nobel-Prize-winning physicist Hannes Alfvén. This surface has been theorized since the 1960s, but has only been explored directly since 2021, when NASA's Parker Solar Probe plunged through it for the first time.

PUNCH tracks space weather and the solar wind itself across the entire inner solar system. This preliminary movie marks the first time a complete halo CME has been tracked all the way across the inner solar system, to impact with Earth.

Although PUNCH is still finishing up commissioning, it is beginning to produce scientifically interesting data. This image is an example: while the complete data processing pipeline is still being refined, the instrument is producing data that reveal the breathtaking beauty of the solar corona and the detailed structure that is the subject of PUNCH science. This image of the corona, during the eruption of a large CME on 6/3/2025, shows the detailed, wispy structure of the background corona and the CME itself.

Downlinking data from space costs money. PUNCH generates a lot of data, which drives the cost of operations – so we do everything we can to reduce the size of each image. We can’t use “lossy” compression algorithms, since a lot of the PUNCH science lives in very faint fluctuations that would be discarded in compression. Coming out of the camera, each WFI image is 8 Megabytes (MB) of 16-bit values. Using JPEG-LS (a lossless algorithm) on the raw images would reduce them to about 3 MB each. But we can (and do) squeeze them further.

PUNCH images of space are now available for download from NASA’s Solar Data Analysis Center (SDAC), in scientific-grade FITS format with relevant pointing and spacecraft-status metadata included. The data are updated twice daily by SDAC from the Science Operation Center (SOC) servers at Southwest Research Institute (SwRI) in Boulder, Colorado – and will continue to update as data arrive from space and are processed by the SOC. The data are also being indexed by the Virtual Solar Observatory. The PUNCH website includes links to documentation for the data and for the mission. Many thanks to Marcus Hughes (PUNCH SOC Lead), Jack Ireland (SDAC Lead), and their teams for opening the taps.