Parker Solar Probe (PSP) made in-situ data collection and captured closest ever images of the Sun during its last closest approach at perihelion in December 2024. These images were processed and released recently on 10 July 2025. Close –up views of collision of multiple coronal mass ejections (CMEs) taking place in outermost solar atmosphere is one of the most important images captured by the probe. Coronal mass ejections (CMEs) are large outbursts of charged particles that are a key driver of space weather effects at Earth and in space.
On 24 December 2024, Parker Solar Probe (PSP) made its closest approach to the Sun at perihelion at a distance of 6.1 million km (for a comparison, distance between earth and Sun is 152 million km) at a speed of 692,000 kmph (the fastest ever speed of any human-made object). The probe passed through corona (the outermost atmosphere of the Sun) and made in-situ data collection and captured the closest ever images of the Sun using various onboard instruments, including the Wide-Field Imager for Solar Probe (WISPR). These images were processed and released recently on 10 July 2025.
The new close-up WISPR images of the Sun reveal the features of corona and solar wind.
One of most important images captured by the probe is close –up views of collision of multiple coronal mass ejections (CMEs), the large outbursts of charged particles that are a key driver of space weather. When CMEs collide, their trajectory can change, making it harder to predict where they’ll end up. Their merger can also accelerate charged particles and mix magnetic fields, which makes the CMEs’ effects potentially more dangerous to astronauts and satellites in space and technology on the ground. Parker Solar Probe’s close-up view helps scientists better prepare for such space weather effects at Earth and beyond.
Understanding origin of solar wind is important for understanding its impact on our space-based enprises and life forms and infrastructure on the Earth. The new images give a closer look at what happens to the solar wind shortly after it is released from the corona. They show the important boundary where the Sun’s magnetic field direction switches from northward to southward, called the heliospheric current sheet.
The close-up views are also enabling us to differentiate the origins of the two types of slow solar wind – Alfvénic (with small-scale switchbacks) and non-Alfvénic (with variations in its magnetic field). The non-Alfvénic wind may come off features called helmet streamers (large loops connecting active regions where some particles can heat up enough to escape) whereas Alfvénic wind might originate near coronal holes, or dark, cool regions in the corona.
Solar wind, the constant stream of electrically charged subatomic particles released from the Sun that spread across the solar system at speeds exceeding 1.6 million kmph is of two types – fast and slow. Fast solar wind is in part powered by switchbacks (zig-zagging magnetic fields in clumps commonly encountered in corona). Slow solar wind travels at half the speed of the fast solar wind (=355 km per second). It is twice as dense and more variable than fast solar wind. Based on the orientation or variability of their magnetic fields, slow solar winds are of two varieties – Alfvénic, has small-scale switchbacks and non-Alfvénic, doesn’t show these variations in its magnetic field. It is important to study slow solar wind because its interplay with the fast solar wind can create moderately strong solar storm conditions at Earth.
Parker Solar Probe (PSP) flies through inner atmosphere of the Sun at 6.2 million km to the Sun at closest approach, making in-situ measurements to trace how energy flows through the corona. Solar Orbiter (SO), on the other hand, makes both in situ and remote sensing observations at 42 million km to the Sun at closest approach. It studies photosphere, outer atmosphere and changes in the solar wind. Recently, Solar Orbiter took first-ever images of the Sun’s south pole for understanding Sun’s activity and solar cycle during its flyby in March 2025. Both Parker Solar Probe (PSP) and Solar Orbiter (SO) are at work in space to unravel functioning of the Sun and the fundamental processes that lead to space weather at Earth.
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References:
- NASA’s Parker Solar Probe Snaps Closest-Ever Images to Sun. 10 July 2025. Available at https://science.nasa.gov/science-research/heliophysics/nasas-parker-solar-probe-snaps-closest-ever-images-to-sun/
- Yardley S.L., 2025. Solar Orbiter and Parker Solar Probe: Multi-viewpoint messengers of the inner heliosphere. Preprint at arXiv. Submitted13 February 2025. DOI: https://doi.org/10.48550/arXiv.2502.09450
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Related article:
- “Parker Solar Probe” Survives Closest Encounter to Sun (27 December 2024)
- Space Weather Forecasting: Researchers Track Solar Wind from Sun to near-Earth environment (2 October 2024)
- Space Weather, Solar Wind Disturbances and Radio Bursts (11 February 2021)
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 made in-situ data collection and captured closest ever images of the Sun during its last closest approach at perihelion in December 2024. These images were processed and released recently on 10 July 2025. Close –up views of collision of multiple coronal mass ejections (CMEs) taking place in outermost solar atmosphere is one of the most important images captured by the probe. Coronal mass ejections (CMEs) are large outbursts of charged particles that are a key driver of space weather effects at Earth and in space.){kind=link}