Jupiter is the largest planet in the solar System.

The cover image shows a processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager from an image captured in 1979.

Planets 8
Eight planets of the solar system.  Credit: Wikipedia

This planet gets its name from the Roman god Jupiter (Zeus in Greek mythology). In Greek mythology, Zeus was the king of the gods, ruler of Mount Olympus, and god of the sky and thunder.

In Roman mythology, Jupiter was the main deity of the Pantheon, forming a triad with Juno and Minerva.

Since Galileo Galilei could see, with his rustic telescope, that there were four moons orbiting Jupiter, thousands of people have been able to admire those 4 moons of the great planet, using simple binoculars.

Jupiter 4 satellites
Jupiter, the Galilean moons. Credit: web “astronomyonline.org/SolarSystem/GalileanMoons.asp”

Jupiter physical characteristics

Jupiter is the planet that offers the greatest brightness throughout the year; in part, due to its immense size and also because it is a gaseous planet, made up mainly of hydrogen and helium.

On the surface it has a cloud structure in bands and zones, located in the direction of the parallels, and in which there is a high degree of turbulence that causes winds with speeds of up to 500 km / hour.

Jupiter’s upper clouds are probably made up of frozen ammonia crystals.

It is the fifth planet in the Solar System, after Mercury, Venus, Earth and Mars.

It is located about 750 million km from the Sun.

It travels the solar orbit in just under 12 years, at an average speed of 13 km / sec.

After the Sun, Jupiter is the largest celestial body in the Solar System.

Its diameter is 142,984 km (11 times greater than that of Earth).

Its density is 1.33 gr / cm3 (a quarter of that of the Earth). Its mass is almost two and a half times that of the other 8 planets together; and 318 times greater than that of Earth.

The astronomical record of Jupiter has characteristics that make it very different from an ordinary planet like Earth.

The composition of Jupiter, a huge sphere of hydrogen and helium, is more like a star than a planet.

It is the only planet that emits radio waves; and the energy it releases to the outside is more than double that it receives from the Sun.

Orbits planets
Orbits of the sun’s Planets  Credit: web “nationalgeographic.org”

Some para-science writers have speculated with the theory that some 3,000 or 4,000 million years ago, there were two stars in the solar system: the Sun , the largest and brightest, and a smaller one: the current planet Jupiter.

Both suns would have constituted a binary system of stars, in the middle of which there would have been a small planet called “Phaethon”.

The gravitational forces of these two suns would have made the planet “Phaethon” explode into hundreds of thousands of fragments, giving rise to the current “asteroid belt” that currently revolve around the Sun, in an orbit located between Mars and Jupiter.

Jupiter Earth
Jupiter is much bigger than earth. Credit: web “muyinteresante.es/ciencia/articulo/”.

Jupiter, with its enormous gravity, draws wandering objects in the Solar System towards it, acting in a sense as a “protective umbrella” for our planet.

Jupiter is an outer planet, as it is further from the Sun than Earth.

The Earth is at an average distance of 150,000 km from the Sun.

On the other hand, Jupiter is at an average distance of 750,000,000 km.

It is also a so-called “gaseous” planet, as it is made up of 81% hydrogen and 17% helium.

Jupiter’s great red spot

In its atmosphere there is a large red spot that is 2.5 times larger than Earth.

Jupiter also has the fastest rotational speed of the planets in the Solar System: it rotates on its axis in just under 10 hours.

Jupiter Red spot
A large red spot can be seen on the surface of Jupiter. Credit: web “nasa.gov/image-feature/hubble-spots-jupiter-s-great-red-spot”

The Hubble Space Telescope took a view of Jupiter, taken on June 27, 2019.

It reveals the giant planet’s trademark Great Red Spot more intense color palette in the clouds swirling in Jupiter’s turbulent atmosphere than seen in previous years.

Jupiter magnetosphere

Jupiter has a large magnetosphere formed by a magnetic field of intensity 10 times greater than that of Earth.

The particles collected by the magnetic field are driven towards the polar regions where they produce impressive auroras.

It is possible that the existence of this magnetosphere is due to the fact that inside Jupiter, hydrogen behaves like a metal, due to the very high pressure.

The rotation of the planet produces electrical currents that, in turn, produce a magnetic field.

Jupiter auroras
Northern Lights at the Pole of Jupiter. Credit: web “nasa.gov/feature/goddard/2016/hubble-captures-vivid-auroras-in-jupiter-s-atmosphere”

Pioneer probes discovered that the shock wave from Jupiter’s magnetosphere extends 26 million kilometers from the planet, with the magnetic tail extending beyond the orbit of Saturn.

Jupiter satellites

The 4 main satellites of Jupiter were discovered by Galileo Galilei, on January 7, 1610.

Jupiter satellites
Jupiter Moons crossing the giant planet. Credit: web “apod.nasa.gov/apod/ap131102.html”.

Moon Io, with a diameter of 3,643 km, is the innermost. It is a volcanic world with a surface in constant renewal.

A group of scientists led by Arizona State University (USA) has created the first geological map of the entire surface of the moon Io, the most enigmatic moon on the planet Jupiter.

The map reveals lava fields, high mountains, and great plains rich in sulfur dioxide. In total, 425 volcanoes are identified.

Europa, the next satellite, with a diameter of 785 km, is an icy world under which the presence of liquid oceans of water and even the presence of life is speculated.

Jupiter 4 moons
The 4 Galilean Moons. Credit: web “astrospeak.weebly.com/the-jovian-moons.html”

Ganymede, with a diameter of 5,622 km, is the largest satellite in the entire solar system. It is composed of an iron core covered by a rocky mantle and ice.

Callisto, has a diameter of 4,900 km, approximately equal to that of the planet Mercury. It is the third largest moon in the solar system. It is located about 1,800,000 km from Jupiter, almost 5 times farther than the Moon from Earth.

In addition to the aforementioned four Galilean satellites, observations made from Earth and from space probes have increased the total number of Jupiter satellites to 67.

Comet Shoemaker-Levy

In July 1994, Comet Shoemaker-Levy hit Jupiter’s atmosphere.

The comet had been disintegrated by the action of Jupiter’s gravity into about 20 fragments in a previous and close pass by the planet.

Numerous observatories around the world carried out intensive planet observation campaigns on the occasion of this unique event.

The impacts detected especially by the Hubble space telescope and the Galileo probe showed the formation of impressive fireballs in the minutes after each impact.

The debris left in the atmosphere was observed as expanding black clouds for weeks propagating like shock waves.

Jupiter looked closely

Since 1973, NASA has sent several space missions to Jupiter to obtain close-up images.

The Pioneer 10 probe flew by Jupiter for the first time in history in December 1973.

In 1974, the Pioneer 11 probe took the first close-up photos of Jupiter, especially its atmosphere, detected its magnetic field, and studied its radiation belts.

In 1979, the Voyager 1 and Voyager 2 missions visited Jupiter. Their findings revolutionized knowledge of the planet and its moons. Its moon Io was found to have extraordinary volcanic activity and that Jupiter also possessed rings.

Cassini Jupiter
Jupiter rings seen from Voyager 2 probe. Artist’s conception of Cassini orbit insertion. Credit: web “https://airandspace.si.edu”

In 1995, the Galileo mission began a mission to explore the planet that was to last 7 years.

The oceans of Europa and several examples of active volcanism were discovered on Io.

The mission concluded by launching the orbiter against the planet itself to avoid a future collision with Europa that could contaminate its ice.

In 2000, the Cassini / Huygens space mission (a joint project of NASA, ESA and ASI) made a distant flyby on its journey to Saturn obtaining a data set comparable in quantity to those obtained by the Voyagers, but of much better quality.

In late February 2007, the planet Jupiter was visited from a distance by the New Horizons probe (from NASA) on its way to Pluto.