As it travels through the corona and into the heliosphere, a CME interacts with the environment, thereby losing coherence once it arrives at Earth. But with BepiColombo (BC) and Parker Solar Probe (PSP) near Mercury at the time — only 0.35 au from the Sun — Palmerio et al. were able to track the timings of CME-related features (in sequence: shock, sheath, ejecta) and compare the data between the probes. In the accompanying images taken by the Wide-Field Imager for Solar Probe inner camera on PSP, the propagating CME shock front hits PSP between the middle and right-most panels (Earth is the brightest spot in each image). The long duration of the sheath measurements, roughly four times greater than similar observations from Earth, suggest that the flank of the CME, rather than the nose, hit the two spacecraft.

In addition, BC and PSP observed much greater-than-expected differences in the structures and timing of the ejecta, considering their small radial distance. Curiously, PSP observed the ejecta first, despite being farther away, suggesting that the nose of the structure was closer to PSP. If some of the disparities can be explained by the relative geometry between the CME and the two spacecraft, the unexplained ones highlight the challenges of understanding the full three-dimensional evolution of CME structure.

当日冕物质抛射穿过日冕并进入日光层时，日冕物质抛射会与环境相互作用，从而在到达地球后失去相干性。但由于当时 BepiColombo (BC) 和 Parker Solar Probe (PSP) 靠近水星，距离太阳只有 0.35 个天文单位，Palmerio 等人。我们能够追踪日冕物质抛射相关特征的时间（按顺序：冲击、鞘层、喷射物）并比较探测器之间的数据。在 PSP 上的太阳探测器内部相机宽视场成像仪拍摄的随附图像中，传播的 CME 激波锋面击中中间和最右侧面板之间的 PSP（地球是每张图像中最亮的点）。鞘层测量的持续时间很长，大约是地球上类似观测结果的四倍，这表明日冕物质抛射的侧面，而不是鼻子，击中了两艘航天器。

此外，考虑到喷射物的径向距离较小，BC 和 PSP 观察到喷射物的结构和时间差异远大于预期。奇怪的是，尽管距离较远，PSP 还是首先观察到了喷射物，这表明该结构的前端距离 PSP 更近。如果一些差异可以通过日冕物质抛射和两个航天器之间的相对几何形状来解释，那么无法解释的差异则凸显了理解日冕物质抛射结构的完整三维演化的挑战。