Measuring gravity in the solar system
Venue: Polo F. Ferrari 1, via Sommarive 5 (Povo) – room A208
- Prof. Luciano Iess - Dipartimento di Ingegneria meccanica e aerospaziale, Sapienza Università di Roma
Gravity determines the motion of planetary bodies, their interior structure, their shape and, ultimately, their landscape. In turn, gravity measurements provide crucial information on the interior structure and evolution of those bodies. Tracking the motion of planets and the propagation of photons as they pass near the sun constitutes the experimental foundation the old and new laws of gravity.
Thanks to the advanced radio-metric systems, we can now measure spacecraft velocities to 10-6 m/s and accelerations to 10-9 m/s2 over time scales as short as 1000 s, everywhere in the solar system. These capabilities have been used by the Juno and Cassini missions to determine the interior structure of Jupiter and Saturn, and to reveal internal oceans on Titan and Enceladus. Cm-level ranging has been recently demonstrated by the ESA spacecraft BepiColombo en route to Mercury, paving the way to improved tests of general relativity. The seminar will review the methods and some recent achievements of gravity measurements in the solar system.
Scientific Coordinator: dt. Albino Perego