Journal Highlights

Description of substorm cycle in Mercury’s magnetosphere

Editor’s Highlight—

This study uses observations from the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft of Mercury’s (southern) magnetospheric lobe. The authors analyze tail loading and unloading phases in a dataset based on 1000 passes. These phases are viewed as characteristic of substorm events. The analysis shows that the average duration of substorms at Mercury is about 3.5 minutes and that these may involve a much larger fraction (up to at least 40%) of the magnetotail lobe flux than at Earth, suggesting that unloading phase is not simply driven by lobe flux pile-up. Overall, this study is an excellent use of MESSENGER data and offers important conclusions regarding the substorm cycle in this dynamic magnetosphere.