On Wednesday, April 26, 2017, NASA’s Cassini spacecraft successfully made its first dive through the narrow gap between the giant planet Saturn and its rings.
This Cassini image shows features in the atmosphere of Saturn from closer than ever before. The view was captured by the spacecraft during its first Grand Finale dive past the gas giant on April 26, 2017. Image credit: NASA / JPL-Caltech / Space Science Institute.
“In the grandest tradition of exploration, Cassini has once again blazed a trail, showing us new wonders and demonstrating where our curiosity can take us if we dare,” said Dr. Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington.
As it dove through the gap, Cassini came within about 1,900 miles (3,000 km) of Saturn’s cloud tops and within about 200 miles (300 km) of the innermost visible edge of the rings.
While mission managers were confident Cassini would pass through the gap successfully, they took extra precautions with this first dive, as the region had never been explored.
“No spacecraft has ever been this close to Saturn before,” said Cassini project manager Dr. Earl Maize, from NASA’s Jet Propulsion Laboratory.
“We could only rely on predictions, based on our experience with Saturn’s other rings, of what we thought this gap between the rings and Saturn would be like.”
“I am delighted to report that Cassini shot through the gap just as we planned and has come out the other side in excellent shape.”
This image shows features in the atmosphere of Saturn from closer than ever before. Image credit: NASA / JPL-Caltech / Space Science Institute.
The gap between the rings and the top of Saturn’s atmosphere is about 1,500 miles (2,000 km) wide.
The best models for the region suggested that if there were ring particles in the area where Cassini crossed the ring plane, they would be tiny, on the scale of smoke particles.
The spacecraft zipped through this region at speeds of about 77,000 mph (124,000 km per hour) relative to the planet, so small particles hitting a sensitive area could potentially have disabled the orbiter.
As a protective measure, Cassini used its large, dish-shaped high-gain antenna (13 feet, or 4 m, across) as a shield, orienting it in the direction of oncoming ring particles.
This meant that Cassini was out of contact with Earth during the ring-plane crossing.
This image shows features in Saturn’s atmosphere from closer than ever before. Image credit: NASA / JPL-Caltech / Space Science Institute.
The spacecraft was programmed to collect science data while close to the gas giant and turn toward Earth to make contact about 20 hours after the crossing.
Cassini’s next ‘Grand Finale’ dive is scheduled for May 2, 2017.
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This article is based on a press-release from the National Aeronautics and Space Administration.
