April 28, 2017
‘Giant hurricane’ on Saturn spotted in latest Cassini dive
Not only did the Cassini spacecraft manage to survive its first dive between Saturn and its rings on Wednesday, but it managed to obtain the closest images of the gas giant’s atmosphere to date – including a picture of what NASA officials are referring to as a “giant hurricane.”
According to Space.com, Cassini came within roughly 1,900 miles (3,000 km) of the Saturn’s cloud tops and within about 200 miles (300 km) of the innermost visible edge of the rings during its April 26 plunge – the first of 22 leading up the mission’s Grand Finale later this year.
After temporarily losing contact with the probe, NASA confirmed in a press release that it had reacquired Cassini’s signal shortly before midnight Pacific time Wednesday night, then started receiving science and engineering data collected during its dive at 12:01am PDT (3:01am EDT) on April 27 at the Deep Space Network Goldstone Complex in California.
“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 HQ in Washington.
During its dive, Cassini passed through a gap between Saturn and its rings that was 1,500 miles (2,000 km) wide, traveling at speeds of approximately 77,000 mph (124,000 km/hour) relative to the planet. Given that scientists were uncertain what it would find in the gap, they turned the probe so that it’s 13-foot (4-meter) wide antenna would protect it, according to Space.com.
One plunge down, 21 to go leading up to the probe’s Grand Finale
Raw images returned by the spacecraft revealed the existence of a dark storm-like feature (which was referred to as a “giant hurricane” in a NASA Twitter post) that was about 1,500 miles across and which was later confirmed to be “the center of the vortex at its pole,” Space.com noted.
Additional unprocessed images gathered during Cassini’s plunge are available online, along with hundreds of thousands collected by the probe during the more than 13 years it has spend studying Saturn and its moons – observations which resulted in the publication of more than 3,000 studies and such discoveries as liquid methane seas at Titan and hydrothermal activity on Enceladus.
“No spacecraft has ever been this close to Saturn before,” Earl Maize, Cassini Project Manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, said in a statement “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.”
Wednesday’s plunge was the first of 22 weekly dives planned for Cassini leading up to its Grand Finale, in which the spacecraft, running low on fuel, will succumb to Saturn’s gravity, enter its atmosphere and burn up. Scientists hope that these maneuvers will help differentiate between the weight of the planet and the weight of its rings, as well as provide new insight into the “ring rain,” the particles that escape from the rings and flow into the planet itself.
Image credit: NASA