25 May 2017

Cassini looks on as solstice arrives at Saturn. The Saturnian solstice occurs about every 15 Earth years

Cassini spacecraft still has a few months to go before it completes its mission in September, but the veteran Saturn explorer reaches a new milestone today. Saturn's solstice - that is, the longest day of summer in the northern hemisphere and the shortest day of winter in the southern hemisphere - arrives today for the planet and its moons. The Saturnian solstice occurs about every 15 Earth years as the planet and its entourage slowly orbit the sun, with the north and south hemispheres alternating their roles as the summer and winter poles.
Reaching the solstice, and observing seasonal changes in the Saturn system along the way, was a primary goal of Cassini's Solstice Mission - the name of Cassini's second extended mission which began in 2010.

"During Cassini's Solstice Mission, we have witnessed -- up close for the first time -- an entire season at Saturn," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. "The Saturn system undergoes dramatic transitions from winter to summer, and thanks to Cassini, we had a ringside seat."
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency (ASI).

ASI is one of the partners of the Cassini mission: on the basis of a cooperation agreement with NASA it has developed for Cassini the high gain antenna with the incorporation of a low-gain antenna (that ensure telecommunications with the Earth for the entire duration of the mission), the VIMS spectrometer, the radio-science subsystem (RSIS) and the radar which also uses the high-gain antenna.
ASI has also developed for the Huygens spacecraft the HASI instrument which measured the physical properties of the atmosphere and Titan's surface.