SWI - Submillimetre Wave Instrument

The Submillimetre Wave Instrument (SWI) will investigate the Galilean moons of the giant planet Jupiter, the chemistry, meteorology, and structure of Jupiter’s middle atmosphere as well as atmospheric and magnetospheric coupling processes. By characterising Jupiter as a planet and possible habitat, and the investigation of more recent active areas within Europa’s ice crust, SWI will provide data for further investigations of habitability on the Galilean moons Ganymede, Europa and Callisto. Furthermore, the instrument will investigate the Jupiter system as an archetype of a gas giant planet and characterise Jupiter’s atmosphere as well as its rings and moons.

SWI is a submillimetre wave heterodyne spectrometer, consisting of two channels that measure spectra in the wavelengths ranges around  520 µm (530 GHz – 625 GHz) and  250 µm (1080 – 1275 GHz) with a spectral resolution of 10⁷.

In this way, SWI will be able to

• perform a detailed characterisation of the dynamics and composition of Jupiter’s stratosphere as well as its coupling to the underlying and overlying atmosphere,
• perform in a unique and unprecedented characterisation of the thin atmospheres and exospheres of the Galilean moons; determine their sources and sinks; investigate the interaction with Jupiter’s magnetosphere,
• determine the dominant isotopic ratios in the atmospheres of Jupiter and the Galilean moons, and therefore the origin and evolution of the entire Jupiter system,
• measure the characteristics of the icy moons’ surfaces and subsurface and their composition,
• determine the molecular composition of plumes caused by cryovolcanic activity as recently observed on Europa in order to constrain the chemical evolution of the satellite’s interior

The Blockdiagram of the Instrument

The CTS is a complex subsystem, which is a unique piece built at the MPS and to date no other real-time spectrometer has flown into "deep space". More infor here.