Cassini’s “dance” with Saturn’s rings continues – the probe has now completed its second dive into the rings (orbit 272), specifically the gap between the innermost rings and Saturn itself. That leaves 20 more similar dives to go, as part of the Grand Finale phase of Cassini’s mission before the fateful end on Sept. 15. This is the closest that any spacecraft has ever come to Saturn, showing the rings and the planet itself in detail never seen before.
Since the previous post about Cassini’s first dive between Saturn and its rings on April 26, more images have become available. These are the closest-ever images taken of Saturn, showing the north polar region with a huge bluish-coloured storm at the centre of the massive “hexagon” jet stream and many other smaller storms and eddies in the atmosphere. As it dove through the gap, Cassini came within about 3,000 kilometres (1,900 miles) of Saturn’s cloud tops and within about 300 kilometres (200 miles) of the innermost visible edge of the rings. Cassini’s next dive through the gap is scheduled for May 2. See also Sophia Nasr’s (@Pharaoness) beautiful and haunting processed Cassini image taken a couple days later, on April 29.
After waiting with bated breath last night, everyone following Cassini’s first-ever dive through the gap between Saturn and its rings let out a collective sigh of relief – the spacecraft made it! This was the first time a probe had ever flown this close to Saturn’s atmosphere and inner rings, and while mission scientists were confident the probe would sail through unharmed, it wasn’t a 100% guarantee, either. But it did, and this is just the first of 22 such dives through this region as part of the “Grand Finale” phase of the mission.
This week marks another important milestone in the Cassini mission at Saturn – as of today, the spacecraft is conducting the last Ring-Grazing Orbit of its mission as it prepares for the Grand Finale, which will culminate in the death of the probe on Sept. 15. On April 21, Cassini will do its very last close flyby of Saturn’s largest moon Titan. Speaking of Titan, Cassini has also apparently solved a perplexing mystery; the unusual “magic island” formations seen in one of the moon’s methane/ethane seas are now thought to be caused by nitrogen bubbles fizzing periodically on the sea’s surface.
NASA’s Cassini mission to Saturn has been one of the most successful and awe-inspiring ever, studying the giant ringed planet and its many moons since 2004. But now, scientists are preparing for what everyone knew would come eventually – the end of Cassini’s excursions throughout the Saturn system. Yesterday, NASA held a news conference to celebrate what Cassini has accomplished and outline what will happen during the next few months, culminating with the end of the mission in September.