NASA’s Cassini Spacecraft Completes 1st Dive Through Gap Between Saturn and Rings –“Beams Back Images of a Colossal Swirling Storm” (WATCH Today’s ‘Galaxy’ Stream)

 

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"No spacecraft has ever been this close to Saturn before," Earl Maize, Cassini project manager and a researcher at NASA's Jet Propulsion Laboratory in California, said. "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." The raw images, which began to stream back early this morning, indicating the probe had survived its journey, show intricate structures and a dark, swirling storm. which NASA called a "giant hurricane".


"Our closest look ever at #Saturn’s atmosphere and giant hurricane," NASA officials wrote in a Twitter post. During a Facebook Live event, researchers later confirmed that the dark storm was the center of the vortex at its pole, stretching 2,000 km across, or almost 1,500 miles.

 

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These unprocessed images shows features in Saturn's atmosphere from closer than ever before. The view was captured by NASA's Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017.

NASA's Cassini spacecraft is back in contact with Earth after its successful first-ever dive through the narrow gap between the planet Saturn and its rings on April 26, 2017. The spacecraft is in the process of beaming back science and engineering data collected during its passage, via NASA's Deep Space Network Goldstone Complex in California's Mojave Desert. The DSN acquired Cassini's signal at 11:56 p.m. PDT on April 26, 2017 (2:56 a.m. EDT on April 27) and data began flowing at 12:01 a.m. PDT (3:01 a.m. EDT) on April 27.

"In the grandest tradition of exploration, NASA's Cassini spacecraft has once again blazed a trail, showing us new wonders and demonstrating where our curiosity can take us if we dare," said 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 kilometers) of Saturn's cloud tops (where the air pressure is 1 bar — comparable to the atmospheric pressure of Earth at sea level) and within about 200 miles (300 kilometers) of the innermost visible edge of the rings. Cassini's next dive through the gap is scheduled for May 2.

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.

The gap between the rings and the top of Saturn's atmosphere is about 1,500 miles (2,000 kilometers) 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 kph) relative to the planet, so small particles hitting a sensitive area could potentially have disabled the spacecraft.

As a protective measure, the spacecraft used its large, dish-shaped high-gain antenna (13 feet or 4 meters across) as a shield, orienting it in the direction of oncoming ring particles. This meant that the spacecraft was out of contact with Earth during the ring-plane crossing, which took place at 2 a.m. PDT (5 a.m. EDT) on April 26. Cassini was programmed to collect science data while close to the planet and turn toward Earth to make contact about 20 hours after the crossing.

The spacecraft came within about 1,900 miles (3,000 kilometers) of Saturn's cloud tops and within 200 miles (300 km) of the rings' innermost visible edge during the plunge, NASA officials said in a statement. Because Cassini scientists and engineers didn't know what to expect of the gap — although it looked clear, unknown dust and debris could have proved harmful — the spacecraft was turned so its 13-foot-wide (4 meter) antenna acted as a shield as it dove, collecting data all the while. Only 20 hours after the pass was it scheduled to turn back toward Earth. Cassini's next dive through the gap is scheduled for May 2.

The image shows below features in Saturn's atmosphere from closer than ever before. The view was captured by the Cassini spacecraft during its first Grand Finale dive past the planet on April 26, 2017. Saturn's atmosphere is relatively cool and mostly made of hydrogen, and the pressure at Saturn's cloud tops is about the same as Earth's pressure at sea level, NASA reported. It hosts layers of clouds and that huge, spinning hexagon-shaped storm on its north pole, as well as more temporary storms that streak across the planet's surface. (One was nearly as wide as Earth.) It also hosts winds among the fastest in the solar system — NASA's Voyager missions, which passed Saturn in 1980 and 1981, measured winds at more than 1,100 mph (1,800 kph).

 

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Unsolved mysteries of Saturn remain to be determined: the exact length of its day and internal structure, as well as the exact composition and age of its rings, which could become clear over the course of Cassini's explorations.

The spacecraft flew through the ring plane at 77,000 mph (124,000 kph) relative to the planet, and at that speed tiny particles could have posed a large threat to its sensitive instruments without the shielding. The rest of Cassini's unprocessed photos from the crossing are available online, along with more than 380,000 images documenting the spacecraft's journey, starting months before it arrived at Saturn in 2004

The spacecraft is in the process of beaming back science and engineering data collected during its passage, via NASA's Deep Space Network Goldstone Complex in California's Mojave Desert. The DSN acquired Cassini's signal at 11:56 p.m. PDT on April 26, 2017 (2:56 a.m. EDT on April 27) and data began flowing at 12:01 a.m. PDT (3:01 a.m. EDT) on April 27.

"In the grandest tradition of exploration, NASA's Cassini spacecraft has once again blazed a trail, showing us new wonders and demonstrating where our curiosity can take us if we dare," said 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 kilometers) of Saturn's cloud tops (where the air pressure is 1 bar — comparable to the atmospheric pressure of Earth at sea level) and within about 200 miles (300 kilometers) 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. 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," said Cassini Project Manager Earl Maize of NASA's Jet Propulsion Laboratory in Pasadena, California. "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."

See highlights from the scene at JPL on April 26-27, 2017, and some of the first raw images the spacecraft sent back from its closest-ever look at Saturn’s atmosphere.

The gap between the rings and the top of Saturn's atmosphere is about 1,500 miles (2,000 kilometers) 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 kph) relative to the planet, so small particles hitting a sensitive area could potentially have disabled the spacecraft.

As a protective measure, the spacecraft used its large, dish-shaped high-gain antenna (13 feet or 4 meters across) as a shield, orienting it in the direction of oncoming ring particles. This meant that the spacecraft was out of contact with Earth during the ring-plane crossing, which took place at 2 a.m. PDT (5 a.m. EDT) on April 26. Cassini was programmed to collect science data while close to the planet and turn toward Earth to make contact about 20 hours after the crossing.

Launched in 1997, Cassini arrived at Saturn in 2004. Following its last close flyby of the large moon Titan on April 21 PDT (April 22 EDT), Cassini began what mission planners are calling its "Grand Finale." During this final chapter, Cassini loops Saturn approximately once per week, making a total of 22 dives between the rings and the planet. Data from this first dive will help engineers understand if and how they will need to protect the spacecraft on its future ring-plane crossings. The spacecraft is on a trajectory that will eventually plunge into Saturn's atmosphere — and end Cassini's mission — on Sept. 15, 2017.

The Daily Galaxy via NASA Cassini and JPL

Image credits: Credits: NASA/JPL-Caltech/Space Science Institute

 

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