Jupiter, first among his own, king of life, lord of seven planets, protector of the kingdom

The largest planet in our solar system has had a major influence on who we are today on Earth

As if they were the titles of King Viserys of House Targaryen. Jupiter, the father of the gods and men, could well be considered the protector of the Solar System and one of those responsible for the appearance of life on Earth (and perhaps also on some of the other seven planets or their satellites). . Today we are talking about the largest planet that orbits the Sun (at least that we know of ).

Among the attributes of the god, Jupiter was the eagle, the thunderbolt, and the scepter. The eagle has been the symbol of majesty, power, and victory throughout history. And really, the influence that the planet Jupiter has had on the Solar System is not negligible.

The god is also known as the father of light—literally meaning “being of light”—since it was understood that the gods were made of the same stuff as light. This origin is also at the base of the word Iovis: “Jove”, another name for Jupiter (it is called the jovian planet), from which the Spanish word “jovial” comes. And he has brought us Earth quite a bit of joy.

Immediately, Jupiter assigned Neptune the kingdom of the seas, and Pluto the Underworld. And then he married Juno, his sister, and fertility goddess. Water and life were linked in mythology, and Jupiter would have influenced one through the other in science as well.

Jupiter, first among his own, king of life, lord of seven planets, protector of the kingdom

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Image of Jupiter taken when the planet was 670 million kilometers from Earth.NASA, ESA, AND A. SIMON (GSFC)

Models of star formation tell us that large clouds of gas begin to collapse, creating denser clumps that pull in more and more material (accreting, a word only astrophysicists use). It is highly unlikely that just a clump would be created in an interstellar gas cloud, so indeed stars do not create on their own. This implies that stars usually form binary or multiple systems, it is estimated that 85% of stars do not live alone (our Sun is rare). Not only that, but stars form in groups, which we call clusters, with tens, hundreds, or thousands of stars in a cubic volume of about 6 light-years on a side, while around the Sun there are only two.

Jovian lump

This multiplicity in the formation of stars from the same maternal cloud seems to also extend to smaller scales, typical of planetary systems. And that’s where Jupiter comes into play. Within the Solar System, almost all the gas in the primordial cloud went to the Sun, but about one in a thousand formed another clump that would eventually give rise to the Jovian planet.

The formation of a planetary system early on is almost like bumper cars. Some lumps of gas orbit around others, all around the center of mass, but they are also gaining mass, perhaps sometimes losing it or merging with other objects. Sometimes we have talked about the problem of three bodies because this is the problem of thousands of relatively massive bodies, millions of small ones, as well as gas and dust (which behave differently). Nothing is easy, but today we have the means and knowledge of physics to simulate how such a system behaves. And there are inquisitive things.

One of the most curious, now focusing on Jupiter, is what is known as the Grand Tack. the word tacking English is used, it seems, for what in Spanish is known as embroidering girdling the wind. I have no idea about sailing, but those abrupt turns that the boats make seem quite aesthetic to me. Well, some of the most realistic models of the formation of the Solar System (although not without problems) tell us that Jupiter was the first planet to form. The other giants didn’t take much longer either, but the fact is that in the first few hundred thousand years of its existence, Jupiter liked to haggle. Its orbit came very close to the Sun, almost as close as the distance between our star and Earth today (at that time we were just one or several protoplanets), and then tacked away again in what must have been tremendous.

The Grand Tack has spectacular, and let’s say vital, implications and possible results. Jupiter’s great mass affects the entire Solar System gravitationally, not as much as our star, but quite a bit. And in those first moments of the Solar System, there was a multitude of asteroids and comets, many more than today. So Jupiter in its excursions must have dragged even Saturn towards orbits closer to the Sun, and also a multitude of comets, composed mainly of water ice. They traveled to an inner Solar System that was quite dry, mainly because it was too hot to hold water that was not in a gaseous state. Those comets could have been the origin of most of the water in our oceans, where life would later begin.

What evidence do we have of this incredible story that tells us that without Jupiter and his love of sailing, there might not be water and life on Earth? It’s too much to talk about today, but there are many issues related to that Grand Tack (if it existed, this is not closed): the existence of an asteroid belt, of 4 terrestrial planets, including Mars that does not follow the progression of increase in size as we move away from the Sun, of a large number of craters on the Moon that indicate that Jupiter could have moved a lot in its origins and thrown material into the Solar System, not only at the time of the Great Tack, but later, or the frequency of catastrophic impacts on Earth, which Jupiter somehow shields with its magnificent mass.


Cosmic Void is a section in which our knowledge about the universe is presented qualitatively and quantitatively. It is intended to explain the importance of understanding the cosmos not only from a scientific point of view but also from a philosophical, social, and economic point of view. The name “cosmic vacuum” refers to the fact that the universe is and is, for the most part, empty, with less than one atom per cubic meter, even though in our environment, paradoxically, there are quintillions of atoms per meter cubic, which invites us to reflect on our existence and the presence of life in the universe. The section comprises Pablo G. Pérez González, a researcher at the Center for Astrobiology; Patricia Sanchez Blazquez, a full professor at the Complutense University of Madrid (UCM); and Eva Villaver, a researcher at the Center for Astrobiology.