Statistical Study of the Solar Wind Current Sheet Properties: Defining Instrument Requirements for the Seven Sisters Mission Concept

The present study performs a procedure of estimating the current sheet (CS) thickness in the solar wind. Motivated by the science requirements for a multi‐spacecraft solar wind mission called the Seven Sisters, this research aims to address the required temporal resolution of the magnetometer in order to entirely encompass the observations of thin CSs. Additionally, this procedure can contribute to addressing the unresolved turbulence heating problem in the solar wind. We have statistically provided the solar wind CS thickness estimated, with full instrumental resolution of 128 Hz, from the Flux Gate magnetometer (FGM) data of the Magnetospheric Multiscale (MMS) mission. Out of 183 cases of solar wind CS crossings, the thicknesses varied from 0.1 to 3 Mm with a maximum of 32.97 s, minimum of 0.16 s and average of 3.08 s crossing time. Of these, 73.22% of the CSs can be identified by using 1‐Hz measurement cadence, while 12.5 Hz data can fully identify all of the CSs. Therefore, it can be concluded that the 1‐Hz sampling rate is sufficient for the survey mode, while the sampling frequency of 12.5 Hz as the burst mode is capable of achieving even the strictest scientific objectives. Our statistical results also report a population below 100 km or 1di $1{d}_{i}$, which should be further examined. Key Points Thin current sheet (CS) thicknesses in the solar wind vary from 0.1 to 3 Mm Most of the CS thicknesses are below 10 ion inertial lengths Minimum instrument resolution to resolve thin CSs in the solar wind is 6.2 Hz