A hidden ocean on Saturn’s small moon

Astronomers have discovered that it is named after a small moon of Saturn Mimasit may have a hidden ocean beneath its thick icy crust and therefore have the conditions for life.

According to Space.com, this shocking finding fundamentally changes the definition of what the Moon can be and could ultimately redefine our search for extraterrestrial life on the moons of the Solar System.

Mimas, nicknamed the “Death Star” because a large crater looks like a space station in “Star Wars,” doesn’t at first look like a celestial body that scientists think could support an ocean.

In fact, it doesn’t even seem capable of supporting such a large body of liquid.

The team behind this discovery estimates that the ocean is approx 20-30 kilometers Beneath the surface of the mima’s frozen shell.

Also, researchers believe that it is relatively young, having appeared only 2-25 million years ago.

However, despite being hidden for millions of years, the ocean is at least half the volume of Saturn’s natural moon, the Moon.

“The most important finding here is the discovery of habitable conditions where we would never — ever — expect water to exist on a solar system object,” he told space.com. Valery Lene“It’s really amazing,” added a member of the discovery team and a scientist at the Paris Observatory.

What research has shown about the hidden ocean

However, this research could change the way experts think about the search for life in the universe.

“Mimas would be the most difficult place to look for the existence of a global ocean,” says the study, published in the journal Nature.

The discovery makes Miman more like Saturn’s “sister” moon Enceladus, which scientists already knew had a subsurface ocean.

It is noted that both moons are at the same distance from the gas giant and are similar in size, with the ice-covered Enceladus about 500 kilometers in diameter and the slightly smaller icy Mima at 396 kilometers in diameter.

The main difference between the two moons is that while Enceladus’ ocean is breaking through its surface with jets, the Mima Sea has not yet breached its icy crust.

This means that while NASA’s Cassini spacecraft has been able to fly through the ice jets ejected from Enceladus to confirm its oceans and even discover some of the complex molecules within them, it has not been able to do the same with Mima.

“It’s really surprising that we haven’t seen anything, but the thickness of Mima’s ice crust is enough to keep this ocean for millions of years without significant activity to betray it,” said Valerie Lenay.

“That’s why Cassini found nothing on Mima’s surface.”

However, that doesn’t mean the Cassini spacecraft, which spent 13 years in the Saturn system before accidentally crashing into the air giant in 2017, didn’t play a key role in helping discover the Mima ocean.

Valerie Lenay and her colleagues discovered the first evidence that Mimas has a buried liquid ocean when they used data from the Cassini spacecraft to study a crack in Saturn’s infamous rings.

The so-called “Cassini section” is a region 4,800 km wide between Saturn’s A ring and B ring, and in 1675 Giovanni Cassini Using a refracting telescope at the Paris Observatory with a focal length of 20 feet and a 2.5-inch objective with 90x magnification.

In 2010, while trying to find out whether a change in Miman’s orbit caused the so-called “Cassini Breakup,” the team noticed a strange change in both the moon’s rotation and its orbit.

Researchers determined in 2014 that these large distortions are the result of Saturn’s moon either having an irregular and solid rocky core, or a subsurface ocean that allows its outer crust to oscillate independently of its core.

The breakthrough came when the team finally modeled Mima’s motion and discovered that the rocky core could only be responsible for the observations if it was long and flat.

Obviously, this didn’t match what the team actually saw, but additionally, the way Miman’s orbit has evolved since 2014 has strengthened the case for a subsurface ocean.

Valerie Lene reported: “There is no rigid interior to match Mima’s spin and trajectory evolution.

“It’s a relief to finally prove that this is the solution.”

“50% of Mima’s volume is filled with water”

The team was not only able to determine whether the oceans existed for only a few million years because of whether Miman’s orbit remained flat or eccentric, but scientists were also able to estimate how much water the oceans could contain. oceans of the moon.

“At least 50% of Mima’s volume is filled with water, which is a very large amount of liquid water for the size of the satellite,” said Valerie Lene.

In fact, the interaction of water and rock is believed to play an important role in the origin and existence of life on Earth, meaning that this kind of chemistry in Mima is indeed an interesting prospect for life and survival in the solar system.

“Mimas is a small, cold-looking object, with no geological activity, and we would never expect any geophysical activity inside it, such as heat or contact between water and silicates in its rocky core,” said Valery Lenay:

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