The new measurement will have immediate benefits for spacecraft navigation.
Cassini and a Huge Telescope
Scientists used NASA’s Cassini spacecraft and the National Science Foundation’s Very Long Baseline Array (VLBA) radio-telescope system to figure out Saturn’s exact position in space.
When scientists name a radio-telescope system ‘Very Long,” they mean it. The massive array of radio-telescope antennas stretch from Hawaii to the Virgin Islands.
Scientists used Cassini’s location in orbit around Saturn to determine where Saturn is. The VLBA found Cassini’s exact position as it received the signal from the spacecraft’s radio transmitter. Then, they combined the data with Cassini’s orbiting data from NASA’s Deep Space Network. With these two batches of data, scientists were able to figure out where Saturn’s center of mass is located to within 2 miles.
“This work is a great step toward tying together our understanding of the orbits of the outer planets of our solar system and those of the inner planets,” said Dayton Jones of JPL, who led the study.
Scientists plan to use similar techniques when NASA’s Juno spacecraft reaches Jupiter next year.