Here is what is Enceladus, the sixth natural satellite of Saturn's brightest, where after some explorations it was assumed that there could be traces of life
Enceladus is a natural satellite of the planet Saturn, whose discovery dates back officially to August 28, 1789 by the British astronomer William Herschel, former discoverer of the planet Uranus. It is the sixth natural satellite of Saturn in order of size and the brightest. A satellite remained "dark" for nearly a century, until the passage of the two probes Voyager in the 80s of the twentieth century that have allowed us to reconstruct its size, rather small, only 500 km and able to reflect almost 100% of sunlight.
In 2005 the discovery of this bright satellite was enriched with additional elements, thanks to a series of explorations in close flight of the probe Cassini. This further exploration revealed that the Enceladus satellite is geologically active and may have evidence of life. Few worlds in our solar system are as compelling as Enceladus, Saturn's icy ocean moon.
At the origins of the mythological satellite Enceladus
The name of this satellite comes from the giant of Greek mythology Enceladus, half man and half beast, son of Gaea (Earth) and Uranus. A name chosen by the son of its discoverer William Herschel, John Herschel, appeared for the first time in some publications of 1847 that reported the reports of astronomical observations made at the Cape of Good Hope.
After all, to stay on topic, Saturn was the equivalent of the god Cronus in Greek mythology, as well as lord of the Titans. William Herschel was able to spot the satellite first, thanks to the use of a new 1.2-meter telescope that, at the time, was the largest in the world. For decades, scientists did not know why Enceladus was the brightest entity in the solar system, or how it was related to the E ring of the planet Saturn...
Enceladus: the characteristics of the brightest satellite
As we said at the beginning, Enceladus has an area of about 500 km in diameter (a bit like the state of Arizona in the USA) and orbits Saturn with direct, almost circular motion at an average distance of 238.020 km, between the orbits of two other moons, Mimas and Tethys. Enceladus completes an orbit every 32.9 hours within the densest part of Saturn's ring. Also, like some other moons in the extended systems of the giant planets, Enceladus is caught in what is called orbital resonance, which is when two or more moons align with their parent planet at regular intervals and interact gravitationally.
Images from the Voyager space probe in the 1980s indicated that although this moon is so small, its icy surface is remarkably smooth in places and bright white for the most part. In fact, Enceladus is the body with the most incredible reflectivity in the solar system. Because Enceladus reflects so much sunlight, the temperature of its surface is extremely cold, about minus 201 degrees Celsius. But it's not as cold and inactive a place as it might seem.
Possible life on Saturn's satellite
Some parts of Enceladus have craters up to 35 kilometers in diameter, while other regions that have few craters indicate major events that show geologically recent conformation, dating back about 100 million years. In particular, the south polar region of Enceladus is almost completely devoid of impact craters.
The area is also littered with house-sized ice boulders and regions sculpted by tectonic patterns unique to this region of Enceladus. Considering the recent formation of the surface, scientists have deduced that the ring would have been generated by particles emitted from the satellite's surface.
In 2005, NASA's Cassini space probe discovered that a number of icy water particles and gases gush from Enceladus' surface at about 400 meters per second. The eruptions appear to be continuous, generating a huge halo of fine ice dust around the satellite, which provides material to Saturn's ring. However, only a small fraction of the material ends up in the ring, while most falls as snow on the satellite's surface, which helps keep Enceladus so bright and shiny.
From gravity measurements based on the Doppler effect and the extent of the satellite's very slight wobble as it orbits Saturn, scientists have determined that the jets are being supplied by a global ocean within the satellite. Scientists believe that Enceladus' ice shell may be 1 to 5 kilometers long toward the south pole.
In addition, the average global thickness of the ice is thought to be about 20 to 25 kilometers. With the presence of the possible global ocean, its unique chemistry and internal heat, Enceladus has become something of a beacon in our search for worlds in the Universe where life might exist.