Measuring the solar wind beyond Pluto
An international team led by Heather Elliott at the Southwest Research Institute is analyzing data from the Solar Wind around Pluto instrument aboard the New Horizons spacecraft. The project aims to characterize the solar wind in the far reaches of the solar system and clarify the transition to interstellar space.
Importance of the solar wind
The solar wind, a continuous stream of charged particles, shapes the heliospheric environment and drives space weather. While it is fast and dense near the Sun, its speed diminishes with distance. The exact behavior in the outer solar system remains poorly understood.
Findings from New Horizons
Measurements indicate a noticeable slowdown of the solar wind at roughly 40 astronomical units from the Sun. This deceleration aligns with theoretical models that predict an increasing influence of the interstellar medium. The observations therefore provide key clues for defining the boundary between the solar system and interstellar space.
Implications for future missions
Improved knowledge of the solar wind assists the planning of upcoming missions targeting the outer solar system or interstellar space. Accurate assessments of radiation and particle fluxes are essential for spacecraft safety and potential crewed voyages.