Thanks to the pairing of NASA’s Cassini’s spacecraft with the National Science Foundation’s Very Long Baseline Array radio-telescope system and NASA’s Cassini satellite, 50 more precise measurements are now possible. The location of the second-largest planet in our solar system, as well as its moons, can be determined by scientists within 2 miles (3 km) Astronomers from the Jet Propulsion Laboratory, Pasadena (California), claim that the feat “improves astronomers’ knowledge of Saturn’s orbit, and benefits spacecraft navigation, and basic physics research.” Dayton Jones, study leader, and his colleagues used VLBA to determine the location of Cassini over the past ten year period by receiving its radio transmitter signal. VLBA is an enormous array of radio-telescope transmitters that span the Virgin Islands and Hawaii. Saturn. NASA/JPL/Space Science Institute. Image Credit: These data were combined with Cassini’s orbit data from NASA’s Deep Space Network. Combining both observations allowed the Astronomers to determine the exact positions of Saturn’s center of mass (or barycenter), and the moons. Scientists from NASA’s Jet Propulsion Laboratory, Pasadena (California) were part of the team. The American Astronomical Society meeting in Seattle was where they presented their findings. The precise measurements were possible due to Cassini’s long-term presence within the Saturn system and the VLBA’s ability process and interpret very fine details. Scientists now have an improved table that predicts the positions of Saturn’s masses, called ephemeris. The ephemeris, a crucial tool in astronomy. Jones stated that this work was a significant step towards tying together our knowledge of orbits of outer and inner planets in our solar system. He also said that these more precise positional data would help to improve interplanetary navigation and enhance the measurements of masses of objects within the solar system. JPL stated that scientists will now be better able predict when Saturn or its rings will pass before background stars. These events “offer astronomers a wide range of research opportunities.” JPL stated that VLBA measurements of Cassini have helped scientists to determine when the rings and/or Saturn will pass behind background stars. This has allowed them to test Albert Einstein’s theory of general relativity more rigorously. The team was responsible for plotting Cassini’s path around Saturn. They started to use new positional data from the ongoing study in 2013.. They can design more efficient maneuvers to the spacecraft thanks to this new ephemeris. This will allow them to save propellant. The previous estimates by the navigators of Saturn’s position and those of its moons were based on data from Cassini’s communications with Earth. The new calculations are 20 more precise thanks to the VLBA data. They plan to keep continuing the collaboration with Cassini and the VLBA through late 2017,, when Cassini’s missions ends. When NASA’s Juno spacecraft reaches Jupiter in the middle -2016., they plan to employ similar techniques. The team hopes to increase orbital information of Jupiter, the largest planet in the solar system. JPL is part of Caltech’s California Institute of Technology. This division manages NASA’s Cassini, Juno and Deep Space Network missions. Part of the National Science Foundation is also the National radio Astronomy Observatory.
