Enceladus, one of planet Saturn's icy moons, might harbor water, and a distant possibility of life, images clicked by the Cassini spacecraft have found. The images fall short of showing liquids but show plumes of ice and vapor that might be emitted by water reservoirs under Enceladus' surface.
“We realize that this is a radical conclusion, that we may have evidence for liquid water within a body so small and so cold. However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms,” said Carolyn Porco, who heads Cassini's imaging team at the Space Science Institute in Colorado. She warned that the findings didn't mean that life was found on Enceladus. “(But) We have significantly broadened the range of the environments in the solar system that might support living organisms,” Porco said.
The images were snapped when Cassini orbited Enceladus several times last year. Earlier, it had earlier sent similar images in 2004 but the scientists weren't clear if the water vapor shown in the images resulted from a malfunction in Cassini's camera. The latest high resolution images, beamed in November last year, showed icy jets and plumes emitting massive quantities of particles at high speeds. Scientists discarded the theory that these particles were produced by vapors created when warm water ice was converted to gas.
“(But) The November images allowed us to find that there are too many small particles for that model to work. Now we believe that a much better model is geysers erupting from bodies of liquid water,” Porco said. Further research into the source of the heat on the South Pole, where the phenomenon was noted, is now required.
“We previously knew of at most three places where active volcanism exists: Jupiter's moon Io, Earth, and possibly Neptune's moon Triton. Cassini changed all that, making Enceladus the latest member of this very exclusive club, and one of the most exciting places in the solar system,” said Dr John Spencer, a Cassini scientist from Southwest Research Institute in Boulder, Colorado.
According to Torrence Johnson, an astronomer from Jet Propulsion Laboratory, Pasadena, this is the first time that evidence of water being so close to the surface of a body other than Earth has been found. The fact holds promises for the moon of Saturn, which is roughly 1.3 billion kilometer away from Earth. Enceladus, which has a diameter of 505 kilometer, is the brightest body of the solar system.
The new images have also explained certain other mysteries that had been observed earlier. “As Cassini approached Saturn, we discovered that the Saturnian system is filled with oxygen atoms. At the time, we had no idea where the oxygen was coming from. Now we know that Enceladus is spewing out water molecules, which break down into oxygen and hydrogen,” said Dr Candy Hansen of NASA's Jet Propulsion Laboratory in Pasadena.
Launched as a collaborative effort between NASA, the European Space Agency and the Italian Space Agency, the Cassini-Huygens mission has been studying Saturn and its moon since 1997. Astronomers would again get a chance to closely observe the Enceladus phenomenon in 2008, when Cassini would fly within 350-kilometer distance of the moon.
