The heliosphere protects the planets from galactic cosmic rays and interstellar gas and dust. The interstellar boundary explorer (ibex) has been probing the global structure of the heliosphere using…

This federal contract award to Trustees of Boston University, a private university, supports research on the structure and evolution of the heliosphere, the bubble-like region of space surrounding the Sun that is shaped by the solar wind. The $77,166.38 grant, awarded by the National Aeronautics and Space Administration (NASA), will enable modeling of energetic neutral atom (ENA) maps to better understand the heliosphere's characteristics, including potential turbulent features in its tail region. The research aims to reconcile recent models proposing a different heliosphere structure than previously thought and to compare the modeled ENA maps with observations from NASA's Interstellar Boundary Explorer (IBEX) spacecraft. This work could provide new insights into the habitability of exoplanets by enhancing our understanding of astrospheres, the heliosphere-like regions around other stars. The contract does not have a set-aside designation.

The heliosphere protects the planets from galactic cosmic rays and interstellar gas and dust. The interstellar boundary explorer (ibex) has been probing the global structure of the heliosphere using energetic neutral atoms (enas). Traditionally, the heliosphere is thought to have a quiescent, comet-like tail, but a recent model of the heliosphere has suggested otherwise. Opher ET AL. (2015) used a single-ION, 3D magnetohydrodynamic model to propose that the structure of the heliosphere might be very different than previously thought. They used a uniform solar wind and unipolar magnetic field configuration to limit numerical dissipation within the model. With this method, opher ET AL. (2015) found that the heliosphere may have turbulent jets in its tail region, creating a􀁅croissant-like􀁅 structure. This new view is being debated within the community. Our proposal will explore how the shape of heliosphere manifests itself in ENA maps with several extensions of the opher ET AL. (2015) model. The proposed work will extend the work of kornbleuth ET AL. (2018), who explored the ENA maps produced by the􀁅croissant-like􀁅 heliosphere with steady state conditions. In the first year, we will study the effects of numerical dissipation on the ENA maps by using the output from a model that describes the solar magnetic field as a dipole (michael ET AL. 2018A) as compared to the unipolar magnetic field used in opher ET AL. (2015). After investigating the effects of numerical dissipation, we will include variable solar cycle conditions to study the effect on the confinement by the solar magnetic field. With this updated model, we will make ENA maps to compare with ibex observations. In the second year, we will use the output of the new multi-ION 3D MHD model that treats pick-up ions as a separate component (opher ET AL. 2018) to create ENA maps, which is crucial because of the role pick-up ions play in the creation of enas in the heliosphere. Additionally, we will make ENA maps with the output of another version of the opher ET AL. (2015) model which treats neutrals kinetically instead of as fluids (michael ET AL. 2018B). The outputs of the MHD model extensions are readily available. The second task is the only task that involves a new MHD solution, while the time dependent solar cycle conditions are already implemented in the code (michael ET AL. 2015). We will model the ENA maps for the ibex energy range and compare our results with their measurements (mccomas ET AL. 2013; schwadron ET AL. 2014). By using ENA maps, we will be able to better understand the structure of the heliosphere and how IT may change as the sun moves through the galaxy. Additionally, by gaining a better understanding of our own heliosphere, we will be able to gain a better understanding of astrospheres around other STARS as well. Since these astrospheres would also filter out higher energy particles like our own heliosphere, learning more about them would give US new insight into the habitability of exoplanets