Today, Wednesday, Oct. 28, 2015, the Cassini spacecraft will make a historic close flyby (dubbed “E21”) of Saturn’s tiny icy moon Enceladus, not only passing very close to the surface, but also making the deepest dive yet through the water vapour geysers which erupt from the south pole. These plumes are connected to a global ocean of salty water deep below the surface ice, which may be a habitable environment for some form of life.
The Cassini spacecraft has just successfully completed the first of three final close flybys of Saturn’s moon Enceladus, and has sent back some spectacular images of the northern regions of this icy and watery world, the best views ever seen so far. Two more upcoming flybys will dive back into the water vapor plumes at the south pole and measure how much heat is emanating from the tiny moon’s interior.
Starting yesterday, the Cassini spacecraft is making the first of three scheduled close flybys of the moon Enceladus, which will provide the first good look at the north polar region of the tiny, water-spraying moon. These will be the final close-up views of this fascinating world during Cassini’s mission, and may help scientists to better understand the potential habitability of Enceladus, which has become a primary target of interest in the search for evidence of life elsewhere.
Along with Jupiter’s moon Europa, Saturn’s moon Enceladus is considered to be one of the best places to look for evidence of life elsewhere in the Solar System, since both moons are now known to have liquid water beneath their icy surfaces. Now, new evidence suggests that Enceladus may be an even better candidate than first thought: data from the Cassini orbiter shows that the moon harbors a global ocean of water beneath the ice crust, just like Europa, instead of a smaller sea beneath the south pole as previously believed.
The exploration of the outer Solar System has revealed a plethora of amazing worlds, the likes of which were little known or even unheard of just a decade ago. Among the most remarkable and tantalizing discoveries are the “ocean moons” such as Europa and Enceladus, which have oceans or seas of liquid water beneath their icy surfaces. Other moons like Titan, Ganymede, and Callisto may also have them, and even some asteroids. Titan also has seas and lakes of liquid methane/ethane on its surface. With all that water, these small worlds have become a primary focus in the search for possible life elsewhere in the Solar System. Now, a new NASA budget proposal wants to take that a step further and fund new missions to these watery moons.
The water vapour geysers on Saturn’s moon Enceladus are one of the most fascinating phenomena in the Solar System; the jets spray far out into space in a dazzling display unseen anywhere else. Known to emanate from the “tiger stripe” fissures at the south pole, they were thought to be separate, distinct plumes erupting from the surface, but now scientists think that they might actually be mostly broader, more diffuse “curtains” of spray along the length of the fissures.
The deep oceans on Earth are teeming with life, despite the cold and darkness, thanks to hydrothermal vents which provide needed heat and nutrients in an otherwise rather uncomfortable environment. Now, the first evidence has been found for current hydrothermal activity elsewhere in the Solar System: on the ocean bottom of Saturn’s moon Enceladus.