Search for: All records

Abstract Stream interaction regions (SIRs) are long-lasting solar wind structures that result from stable fast solar wind interacting with preceding slow solar wind. These structures have been examined in depth throughout the heliosphere, particularly at 1 au; however, due to sparse observations, SIRs have not been characterized thoroughly at 1.5 au. Thanks to the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, we have a chance to fill this observational gap. We implement in situ solar wind data collected by MAVEN to identify SIRs between 2014 November and 2023 September. We observe 185 SIRs with average durations of 2.2 days that occur primarily during periods of low solar activity. We detect 19 forward shocks, seven reverse shocks, and one shock pair within these 185 SIRs. We predict a total SIR-associated shock detection rate of ∼56% at 1.5 au and compare this rate to previous findings spanning 0.1–5 au. We examine Solar Terrestrial Relations Observatory (STEREO) A data at 1 au to cross-compare with our results at 1.5 au. We determine the magnetic compression ratios (H) associated with SIRs at MAVEN and STEREO-A and find thatHis ∼18% higher at 1.5 au than 1 au. We find that for a given SIR observed at both 1 and 1.5 au,His ∼32% higher at 1.5 au. We also do not see a stark difference in the change inHfor SIRs observed at both STEREO-A and MAVEN with respect to the angular separation of the spacecraft. 

This paper outlines the science and basic design choices associated with a mission concept study known as the LaboratOry for the Behavior of the SloT Region (LOBSTR). This mission concept focuses on energetic particles, both electrons and protons, as they impinge upon the slot region in the Van Allen radiation belts around Earth. In particular, it emphasizes the drift dynamics of particles that were not captured by Van Allen Probes. We conceptualize a mission, utilizing state-of-the-art instruments and components, and calculate the mission’s orbit, thrust, and radiation requirements using industry-standard methods. The concept uses two SmallSats in a near-equatorial orbit, with precise orbital timing to capture the desired dynamics. The total radiation dose and the details of the orbital dynamics are examined and found to be within the capabilities of current technology.