Cassini heads for fiery finalé on Saturn

NASA is planning to fly a spacecraft to its fiery death on Saturn. The spectacular final act of the Cassini will help ensure humanity doesn’t accidentally infect other parts of the solar system with aliens carried there from earth.

Cassini arrived at Saturn in July 2004 and has been exploring the giant planet and its 62 known moons. That includes Titan, which looks like the early Earth, and Enceladus, which has an ocean, spurts ice particles into space and has been mentioned as a candidate for having life. To ensure the craft doesn’t accidentally land on one of those moons and take with it some living organisms that could infest it, Nasa will crash the spacecraft into Saturn. As it does so, it will burn up and get rid of any hitchhikers.

But before its demise, Cassini has one last mission. On April 22, it will make a final pass by Titan and use the moon’s gravity to slingshot itself into a new orbit that passes inside the 1 931km-wide gap between the edge of Saturn’s atmosphere and its innermost rings.

Nasa is hoping Cassini will survive long enough for 22 dives inside the rings, revealing details about the their age and composition. But if a ring particle hits Cassini, it could bring the mission to a premature end – it will be travelling at more than112 654km per hour.

“At those speeds, even a tiny particle can do damage,” flight engineer Joan Stupik, with Nasa’s Jet Propulsion Laboratory in Pasadena, California, said.

Scientists hope to learn if the rings are as old as Saturn – roughly 4.6 billion years – or if they formed later after a passing comet or moon was shredded by the planet’s tremendous gravity. During the close ring encounters, Cassini also will study Saturn’s atmosphere and take measurements to determine the size of the rocky core believed to exist at the centre of the gigantic ball of gas that accounts for most of its size.

However long Cassini lasts, “the grand finale will be spectacular”, said project scientist Linda Spilker, also with the laboratory.

“We’re flying in a region that has never been explored,” she said. “I wouldn’t be surprised if some of the discoveries we make during the grand finalé are the best of the mission.” – The Independent