11,000 salmon lost in fish farm escape
A PIONEERING spacecraft that has transformed knowledge of Saturn and its moons has ended its mission with a spectacular suicide dive into the ringed planet’s atmosphere.
The American space agency Nasa carried out the destruction of Cassini to bring to a close what it called “a thrilling epoch” in space exploration.
For 13 years, the 22ft nuclearpowered probe had been gathering a treasure trove of images and data from the Saturnian system.
At 12.55pm UK time yesterday, all communication with the craft was lost as Cassini tumbled to its doom 930 miles above Saturn’s cloud tops. Plummeting at 77,000mph, it took less than a minute to disintegrate into fragments and burn up.
Mission controllers at Nasa’s Jet Propulsion Laboratory in Pasadena, California, clapped and hugged each other when the end of radio contact was confirmed.
Scientists talked of “bittersweet” emotions, both sadness at Cassini’s loss and intense pride in what they had achieved.
Cassini project manager Dr Earl Maize, who directed Cassini’s final moments from the Jet Propulsion Laboratory (JPL) control room in Pasadena, said: “The Cassini operations team did an absolutely stellar job guiding the spacecraft to its noble end. What a way to go. Truly a blaze of glory.”
Project scientist Dr Linda Spilker added: “Things never will be quite the same for those of us on the Cassini team now that the spacecraft is no longer flying. But we take comfort knowing that every time we look up at Saturn in the night sky, part of Cassini will be there, too.”
The decision to kill off Cassini was taken because the craft would soon run out of fuel and become impossible to steer.
Scientists feared a collision with Titan or Enceladus, two of Saturn’s moons that in the past 10 years have shown a potential to host simple life. Safe disposal of Cassini was seen as the best way to avoid the remote possibility of contaminating the pristine moons with Earth bugs.
The spacecraft, launched from Cape Canaveral in Florida in 1997, took seven years to reach Saturn and was originally intended to explore the planet and its moons for just three years.
In the end its life was extended by another decade.
One of Cassini’s most important discoveries was the existence of a global watery ocean under the icy surface of Enceladus that could conceivably harbour life. Cassini has also discovered seven new moons, six of which have been named, observed raging storms on Saturn and shed new light on the planet’s famous rings.
River workers have expressed concern for the purity of wild salmon in Argyll and Bute after a fish farm escape led to 11,000 farmed fish entering rivers.
The escape was from a Scottish Salmon Company farm at Geasgill on Mull.
Greg Marsh, of the Scottish Gamekeepers Association, said: “What effect is this going to have on the wild fish? What will fisheries be offering in three or four years’ time? Fish of unknown genetic purity.”
He said fish farms needed to take security more seriously.
The Cassini spacecraft which had probed the Saturn and its moons for the last 13 years was yesterday destroyed as Nasa scientists crashed it into the ringed planet’s atmosphere; mission controllers hugged each other when the end of radio contact was confirmed.