World Bulletin / News Desk
After 20 years in space, NASA's famed Cassini spacecraft made its final death plunge into Saturn on Friday, ending a storied mission that scientists say taught us nearly everything we know about Saturn today and transformed the way we think about life elsewhere in the solar system.
"The signal from the spacecraft is gone," said Cassini program manager Earl Maize of NASA's Jet Propulsion Laboratory.
"I hope you are all as deeply proud of this amazing accomplishment," he told colleagues at mission control. "This has been an incredible mission, an incredible spacecraft and you are all an incredible team."
Cassini's final contact with Earth came at 7:55 am EDT (1155 GMT). Its descent into Saturn's atmosphere began about an hour and a half earlier, but the signal took that long to reach Earth because of the vast distance.
Cassini's plunge into the ringed gas giant -- the furthest planet visible from Earth with the naked eye -- came after the spacecraft ran out of rocket fuel after a journey of some 4.9 billion miles (7.9 billion kilometers).
Its well-planned demise was a way to prevent any damage to Saturn's ocean-bearing moons Titan and Enceladus, which scientists want to keep pristine for future exploration because they may contain some form of life.
"There are international treaties that require that we can't just leave a derelict spacecraft in orbit around a planet like Saturn, which has prebiotic moons," said Maize.
Three other spacecraft have flown by Saturn -- Pioneer 11 in 1979, followed by Voyager 1 and 2 in the 1980s.
But none have studied Saturn in such detail as Cassini, named after the French-Italian astronomer Giovanni Domenico Cassini, who discovered in the 17th century that Saturn had several moons and a gap between its rings.
"This is the final chapter of an amazing mission, but it's also a new beginning,” said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate.
"Cassini's discovery of ocean worlds at Titan and Enceladus changed everything, shaking our views to the core about surprising places to search for potential life beyond Earth."Güncelleme Tarihi: 15 Eylül 2017, 17:35