Pluto's interaction with its space environment: Solar wind, energetic particles, and dust

Area of Science:

• Planetary Science
• Heliophysics
• Space Physics

Background:

• The New Horizons spacecraft conducted a flyby of Pluto on July 14, 2015.
• Understanding Pluto's space environment is crucial for planetary science.

Purpose of the Study:

• To measure the space environment near Pluto during the New Horizons flyby.
• To analyze the interaction between Pluto and the solar wind.

Main Methods:

• Utilized three instruments aboard the New Horizons spacecraft: SWAP, PEPSSI, and the Venetia Burney Student Dust Counter.
• Measured solar wind, energetic particles, and dust density in Pluto's vicinity.

Main Results:

• The Solar Wind Around Pluto (SWAP) instrument detected a compact interaction region sunward of Pluto (within 6 Pluto radii).
• Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) data indicated ion acceleration/deflection and observed reduced suprathermal particle fluxes in Pluto's wake.
• The Venetia Burney Student Dust Counter set an upper limit for dust density in the Pluto system (<4.6 km⁻³).

Conclusions:

• Pluto's interaction region with the solar wind is smaller than expected, suggesting reduced atmospheric escape and high solar wind flux.
• The observed particle behavior and low dust density provide insights into the Pluto system's unique space environment.