Heliosphere Shape

A crescent shaped heliosphere

One of the critical questions now debated in heliosphere consists of ‘what is the basic shape of the heliosphere’. The standard picture of a comet-like heliosphere (Baranov & Malama 1993) has been the dominant paradigm since the 1960s. Prof. Opher has revisited this paradigm. She and her colleagues showed  that the magnetic tension of the solar magnetic field plays a crucial role in organizing the solar wind into two jet-like structures. The solar wind is confined in these turbulent  heliospheric jets. She showed that the heliosphere shape is croissant-like. This work was displayed on the July 2020 cover of Nature Astronomy. Most recently she and her colleagues at SHIELD DRIVE center demonstrated that Rayleigh-Taylor-like instability may occur along the solar magnetic axis. This instability destroys the coherence of the heliospheric jets and generates turbulence which leads to magnetic reconnection, allowing interstellar material to enter the heliotail. This instability seems the key to understanding the “Croissant-like” heliosphere.