NASA's Saturn Probe To Graze Past Planet's Rings

For the past 12 years, NASA’s Cassini spacecraft has orbited Saturn, taking some of the most detailed images of the gas giant yet captured. Now, it’s time for the spacecraft, launched in 1997, to retire – but not before diving through unexplored regions and grazing past edges of the planet’s main rings. During its journey, Cassini has made numerous dramatic discoveries, including a global ocean within Enceladus and liquid methane seas on Titan. Engineers have been pumping up the spacecraft’s orbit around Saturn this year to increase its tilt with respect to the planet’s equator and rings. Following a gravitational nudge from Saturn’s moon Titan, Cassini will enter the first phase of the mission’s dramatic endgame on Thursday. Researchers calling this phase Cassini’s ‘ring-Grazing Orbits’, because they’ll be skimming past the outer edge of the rings. In addition, they have two instruments that can sample particles and gases as they cross the ring plane, so in a sense Cassini is also ‘grazing’ on the rings. Cassini will circle over and under the poles of Saturn till April 22 next year, diving every seven days – a total of 20 times – through the unexplored regions at the outer edges of the main rings. During the first two orbits, the spacecraft will pass directly through an extremely faint ring produced by tiny meteors striking the two small moons Janus and Epimetheus. Ring crossings in March and April will send the spacecraft through the dusty outer reaches of the F ring that marks the outer boundary of the main ring system.