How Jupiter and the Moon affect our lives

The isotopic properties of the compound can be used to study its origin and evolution, and we can apply this technique to study the origin of water on Earth. So what do we know about water on our planet? First of all, there is no other place except Earth. in the solar system Or beyond that we know for sure that it contains liquid water.

We know that there is snow made of water on the moon and on Europa and Enceladus (the moons of Jupiter and Saturn, respectively), or on comets like 67P/Churyamov-Gerasimenko. We also know of the presence of water vapor in the frigid volcanoes of these moons and in the interstellar medium, especially near areas where stars are forming. Is all this water the same? Do they have the same isotopic structure?

It just so happens that there is a paradox in the origin water on earth. The environment in which the Sun and Earth originated was quite dry, although water is one of the most abundant compounds in the star-forming regions where the Sun and Earth evolved. Indeed, according to scientific models, rocky planets such as Earth appeared in a region close to the Sun of the Solar System. Here, the high temperature prevented the formation of a type of atmosphere where water could evolve beyond the gaseous state. In this way, the formation of water escaped the gravitational force of the planet.

The presence of carbon, the other basis of life on Earth, also contains a paradox. Carbon is the fourth most abundant element in the universe after hydrogen, helium and oxygen and the second most abundant element in our bodies (about 20% of our body mass is carbon). However, carbon is ten times less abundant on Earth than it is in the universe as a whole.

However, what is the importance of carbon here?

Well, a small part (about 5%) of the meteorites that reach our planet today have a high carbon content. They are called carbonaceous chondrites, and interestingly enough, they also contain large amounts of water. This means that it must have formed in regions far from the sun, beyond what is known as the “frost line,” where temperatures were already well below what, in the early solar system, allowed ice to form from water, methane or ammonia. . . This is one reason why water reached Earth by bombarding these meteorites during a period when the Earth had already cooled since its formation.

In fact, another question is when did the water arrive. There is evidence that it existed on our planet 4.4 billion years ago, more than 100 million years after its formation, when the surface temperature of our planet was low enough for water to freeze. This evidence is based on the study of certain minerals such as zircon, which resists geological changes and the work of the atmosphere well, giving us information about the origins but not so much about the evolution of water on Earth.

Studying the “isotopic abundance” of water in carbonaceous chondrites, at least in the oldest solar system itself, produces results very similar to those on Earth. In particular, the amount of deuterium versus protium is often studied, since the ratio of these isotopes to Earth’s water is quite similar for chondrites near Jupiter, and some from the asteroid Vesta. far away (for example, in outer tributary comets for the solar system), the abundance of deuterium is much higher, and it occurs in what is known as the Oort cloud.

So what do Jupiter and the moon have to do with the whole story of water on Earth? In the case of Jupiter, its effect on matter comes from its strong gravitational influence on the solar system, which moves the orbits of many asteroids. Some evolutionary models suggest that at some point in the history of the solar system, Jupiter may not have had the same orbit as it does today; Instead, it may have been closer to the Sun before it migrated toward its current position. This Jupiter’s flight would have had to sweep objects along the way, which in turn could have been thrown in droves into inner orbits closer to the Sun, thus reaching Earth. This is known as the “late bombardment,” which is evidenced, for example, by the concentration of meteor impacts on the Moon about 3.9 billion years ago.

This is where he plays the role of the moon. To understand this, we must return to the study of isotopes, but this time we are talking about molybdenum, which is a very rare element. Molybdenum is a metal with 42 protons (for comparison, iron has 26) and dozens of isotopes. It turns out that the relative abundance of these isotopes on Earth lies in the middle of the observed abundance of carbonaceous chondrites and chondrites from the distant reaches of the Solar System.

Considering that molybdenum is more dense than iron (a small one-centimeter cube of metal weighs 10 grams, versus seven grams if it’s iron and one gram if it’s water), most of the iron on our planet is intrinsic. , it would not be surprising to think that the molybdenum that came to Earth at the beginning of its history has sunk into the Earth’s core. Surface molybdenum, in the crust or upper mantle, could have a more recent origin, and its isotopic composition indicates regions where there is a lot of carbon and water. The moment links the arrival of molybdenum and water to the impact of Theia, the protoplanet that caused the formation of the Moon after it collided with Earth 4.5 billion years ago, mixing much of its matter with Earth’s mantle. According to these “molybdenum studies”, Theia will be a planet that does not come from the region of rocky planets, but from the region of gaseous planets (Jupiter, Saturn) and / or icy planets (Uranus, Neptune), which are filled with water.

Therefore, although the evidence is not conclusive, it is possible that the planetary catastrophe caused by Theia, with the consequent formation of the Moon, possibly mediated by Jupiter, had a great influence on the emergence of life for several reasons, among which the representation from most of the existing water Today on Earth, our planet.

And so, when we are thirsty, let us consider that our lives may be more connected with the stars than we think, and that, in addition to stardust, we are the products of the struggle of the giants.