Science

RPC Scientific Objectives

The Rosetta mission has allowed plasma physicists to investigate for the first time the evolution of the coma and its interaction with the interplanetary medium along the journey of the comet around the Sun, from a distance of more than 3 AU down to 1.24 AU at perihelion.

The measurements taken by the RPC instruments have allowed scientists to investigate:

  • Physical properties of the nucleus
    • Detection of early activity of the cometary nucleus upon arrival at the comet in August 2014 (3.6 AU from the Sun) and all the way to the end of mission in Sept 2016 (3.8 AU from the Sun),  with the presence of sublimation activity, evidence of early phases of ion pickup processes. The direct detection of these ions has been possible, as the effect in terms of the increase of plasma wave activity.
    • Analysis of the electromagnetic activity in the region surrounding the nucleus showed that the cometary nucleus itself is not magnetised.
  • Inner coma structure, dynamics and aeronomy
    • Determination of the physical processes controlling the mass flow, time evolution and plasma structure of the inner coma and its interaction with the solar wind, energetic ions and fields. Diamagnetic regions were detected and their origin and formation are being studied.
  • Onset and development of cometary activity
    • Presence of neutral gas and plasma around the nucleus were detected from the time of arrival at C-G all the way to the end of the mission. The densest coma, was observed near perihelion.
    • Identification and quantification of the ionisation sources, plasma loss, and acceleration processes.
  • Solar wind interaction
    • Physics of the contact surface: its development, structure and stability.
    • Exploration of the inner cometary coma and cavity-tail connection region.
    • Development of boundries in the plasma near the comet.
  • Formation and evolution of the plasma tail
    • Tail structures and tail ray formation region.
    • Tail disconnection event studies.

The RPC team at Imperial College is involved in multi-instrumental analysis of the Rosetta RPC and ROSINA dataset (find out more).