сен 26, 2019
Saturn moon Enceladus is throwing snowballs at other moons...
Saturn is a planet rich in cosmic curiosity. This gaseous giant has more than sixty natural satellites in its orbit. However, most of them are small bodies, and only nine moons have a diameter of more than one hundred kilometres. One of them, Enceladus, is fighting a cosmic snowball fight.
According to astronomers, the planet's inner moons are strangely bright. This has a raison d'être and researchers think it is due to the fact that this moon is throwing snow at others.
NASA: Cassini is dead, but there's still a lot to discover.
Many of the discoveries made on this planet, at an average distance from the Earth of 1,280,4000,000 km, are from the images and analyses made by the Cassini spaceship. This, as is well known, ended its mission to fly to the interior of Saturn in 2017.
In addition to fantastic images, Cassini brought with him a radar instrument that used radio waves to examine Saturn's frozen moons.
Alice Le Gall of the University of Paris-Saclay, France, and her colleagues analyzed these radar observations and found that three of the moons, Mimas, Encélado and Tétis, appear to be twice as bright as previously thought.
Saturn: Why is there such a bright Moon?
There are some data that can explain this candor of the moon Enceladus. This moon has enormous geysers that throw water from its underground ocean into space. Later, this water freezes and falls like snow on the nearby moons. In addition, much of this snow falls on the surface of the Enceladus. Le Gall and his colleagues calculated that this layer of ice and snow should be at least a few dozen centimeters thick.
Now we know that snow is actually accumulating, it is not just a thin layer of coating, but a much thicker layer of water ice.
Astronomer Le Gall explained.
This helps explain why the moons are so bright in radio wavelengths. This technology penetrates deeper beneath the surface than visible light. However, even deep snow cannot fully explain the brightness of the moons.
This suggests that something else should be buried under the snow or resting on it. This is because the radio waves from the ship's radar were reflected.
Le Gall and his team are in the process of modeling different structures that could answer these questions. In this way, explaining one of these realities could be a layer of snowballs, huge ice peaks or generalized cracks. However, these various probabilities still do not correspond in the observations made to make it geologically plausible.
We have many structures to test, and it is really very important for future missions that can land on these moons.
Le Gall concluded.
Actually, this is an important process, because if we ever want to land there, we need to know what the surface looks like first.
Hubble has just captured an impressive new image of Saturn... it doesn't even look real!