The Cassini probe, mass 5,712 kg, is in a circular orbit with a radius of 1.2108 m around the planet Saturn. How much work must its engine do to change it to a circular orbit with a radius of 1.1109 m?
[Mass of Saturn = 5.681026 kg]

[Specify units of 'J', 'kJ' or 'MJ' in your answer.]