Magnetometers can detect tiny amounts of hydrogen originating from Venus in the solar wind by sensing small variations in the magnetic field
caused by the presence of these particles in the undisturbed solar wind. Analysing these variations, or plasma waves, one can calculate how much of
the hydrogen in the solar wind originates from Venus. Since all of these particles escape the planet, one can calculate how much hydrogen is lost
outside the plasma wake.

The plasma analyser ASPERA is able to measure hydrogen (H+) originating from Venus in the wake. One can also calculate how much is lost
through the wake. This number is much higher than what is lost in the solar wind, therefore: Venus loses its hydrogen through the wake!