The existence of water at Saturn's satellite "Enceladus" is more reliable in the gravity map survey
As one of Saturn's satellites before "Enceladus"Although it is said that there is a possibility that water may exist, newly investigating the gravity distribution of the ground surface has made it almost certain that a large amount of water is present in the basement. This is a discovery that leads to the existence of extraterrestrial life in the solar system.
The Gravity Field and Interior Structure of Enceladus
Under Icy Surface of a Saturn Moon Lies a Sea of Water, Scientists Say - NYTimes.com
The satellite Enceladus, which has a diameter of about 500 km and reflects the light because it is covered with ice, looks bright, the 2005 Saturn probeCassiniAccording to the survey by, it is known that there is a trace of atmosphere on the surface.
The main constituent of the atmosphere is seen as steam, but Encheladus is weak in gravity, so the atmosphere can not escape to outer space soon and it is impossible to keep it, so that there is a minute amount of atmospheric air (water vapor) will always be supplied continuously It was expected that there would be a mechanism for it.
In 2006, Cassini discovers that there are countless cracks on the surface of Enceladus covered with ice. "Tiger Stripes"This crack, which was named" continuous ", was presumed to be supplied internally by some mechanism. And since it was confirmed from this crack that ice particles and steam were squirting, it was ensured that liquid water was present inside Encheladus.
It was also Cassini that made sure of the presence of water. Cassini did not have any equipment to observe the existence of water, but the three times we tried to create the satellite's gravity mapSwing byDiscovered that the gravity of the Antarctica part of Encheladus was weaker than it was predicted.
Dr. Stevenson, who has conducted an investigation of Enceladus, said, "Cassini's findings are that substances denser than ice, perhaps water exist under the ice on the satellite surface It shows that it is doing. " It is said that the water coincides with the actual phenomenon if it is calculated assuming that the water density is 8% higher than the ice and a layer of water exists between 32 km to 40 km underground of the ice. The anticipated water thickness is about 9 km, spreading to the vicinity of the equator centering on the South Pole, and its size is one of the Great LakesLake SuperiorIt is considered to be comparable to.
Here is an imaginary chart showing the inside of Enceladus. The diameter of the satellite is about 500 km, about the same size as Arizona state. The surface is covered with a layer of ice and water melted by friction with the core made of rock is thought to be jetting out from the crack to the surface.
With this discovery, the possibility of extraterrestrial life in the solar system is being told newly. The possibility of life is considered at the present timeMars,Enceladus, Jupiter's satelliteEuropa, And the same Saturn's satellite as EnceladusTitanFour of them. The elements necessary for the existence of life are said to be "liquid water" "energy" "carbon" "nitrogen", but Mars has a shortage of nitrogen, the surface of the planet dries and is very cold State. It is thought that water is present in the basement of ice while unidentified in Europa,Ejection of water can be seenIt is observed that the scale of things is small. It is thought that there is a possibility of life because the ocean exists also in Titan, but the sea is made of methane, even if life exists, it has a form different from that of the earth It is considered to be.
Dr. Christopher McKay, a researcher at NASA · Ames Space Center, says that it is "to take home the sample of the celestial body" as to whether the existence of life exists in Enceladus or the existence of life existed. It is to fly the spacecraft to the vicinity of the satellite newly and collect the trace substances floating in the space and bring it back to the earth, but if it is possible to respond to the gravity of Enceladus, once Japanese"Hayabusa" brought back a sample of the asteroid ItokawaSuch a method may be possible, too. Is it possible for human beings to find life-forms outside the earth?
in Science, Posted by darkhorse_log