SWOOPS Instrument Page

SWOOPS stands for "Solar Wind Observations Over the Poles of the Sun". This Solar Wind Plasma Experiment onboard Ulysses is basically making a map of the interplanetary plasma within the heliosphere (i.e., plasma that has come from the Sun is referred to as the solar wind). You see, the SWOOPS experiment measured the condition and direction of the flow of solar plasma as Ulysses flew past Jupiter and it is measuring the solar plasma in its inclined orbit around the Sun. This will give us the best 3-D map of the solar plasma within heliosphere that we have ever had!

The Solar Wind Plasma Experiment on Ulysses is actually made up of two instruments, the ion spectrometer and the electron spectrometer. The ion spectrometer measures the positive ions within the solar wind and the electron spectrometer measures the free electrons within the solar wind. That way, solar wind electrons and ions can be measured simultaneously.

SWOOPS measurements determine the speed, direction and density of the solar wind flow. The measurements also map the ion and electron temperatures. From these, things like mass flux, momentum flux and solar wind pressure can be derived.

SWOOPS measurements have led to the discovery of a new class of solar wind disturbances. These forward-reverse shock pairs found in high latitudes are driven by the over-expansion of CME's. Perhaps most importantly, SWOOPS has helped us fill in the holes to mapping the solar wind flow throughout the heliosphere. Solar wind disturbances are capable of producing space weather events that can affect our satellites and our life on Earth. In order to better understand and predict these space weather events, we need to understand the Earth's surroundings. SWOOPS is helping us do just that.

Last modified January 24, 2001 by Jennifer Bergman.

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