The physics of the deep Earth are complicated, so establishing the mantle's
basic physical properties, such as density and viscosity, is an important step.
Thus astronomers can interrogate the photons to reveal
the basic physical properties, like velocity and density, of gas passing through shock waves in the jets.
«New Horizons has finally nailed
the basic physical properties of Hydra,» says Hal Weaver, New Horizons Project Scientist and LORRI science operations lead.