NASA launched the Cassini-Huygens space probe into orbit in 1997 in a joint mission with the European Space Agency and Italian Space Agency. The probe’s job was to study the planet Saturn and its nearby moons. However, in November 2005, it made a discovery that would stun the scientific world.
During a fly-by of Enceladus, the sixth-largest moon of Saturn, Cassini discovered water-rich plumes venting from the south polar region.
Carolyn Porco, who headed up the mission, revealed what they found during Brian Cox’s BBC series “Wonders Of The Universe”.
She took Professor Cox to the continental divide in Iceland, where two tectonic plates meet, to explain the phenomenon.
She said: “Enceladus is one of the most unique places in all of the solar system and you can tell that by just looking at it.
“We think that it is possible that something similar to what is happening here, (tectonic plates shifting) where you get slushy ice that comes up through the cracks and creates more surface ice, is happening there.
“It gives us an indication to how the whole system is working down there.”
However, the science world was hit by a second shock when Cassini reported back thermal readings showing “tiger stripes” below the cracks of Saturn’s moon.
This suggests there is extreme heat below the coldest part of Enceladus.
Ms Porco added: “Cassini has found the unthinkable.
“It has found that the southern tip of Enceladus is excessively warm.
“There is more heat coming out the polar caps than the rest of the planet, it would be like saying there’s more heat coming out Antarctica than the equator.
“Those images blew everybody away, it was like game over.”
The November 2005 images showed plumes of ice being shot out more than 300 miles into the atmosphere, like geyser activity seen on Earth.
Observations during a flyby on March 12, 2008, revealed additional chemicals in the plume, including trace amounts of simple hydrocarbons such as methane, propane, acetylene and formaldehyde.
The mechanism that drives and sustains the eruptions is thought to be tidal heating.