Jupiter is the largest planet in our solar system. With a mass exceeding that of all the other planets combined, Jupiter dominates the outer region of the solar system.
This gas giant, located at an average distance of 778 million kilometers from the Sun, has been the object of admiration and study for centuries. From its discovery to modern missions studying it closely, Jupiter continues to reveal surprising details about its composition, its atmosphere, its moons and its history.
Basic facts and characteristics of Jupiter
- Diameter : With a diameter of 142,984 kilometers, Jupiter is 11 times larger than Earth, making it the largest planet in our solar system.
- Mass : Jupiter's mass is about 318 times that of Earth. In fact, its mass is 2.5 times that of all the other planets combined.
- Composition : Jupiter is a gas giant, meaning it does not have a solid surface like Earth or Mars. Its atmosphere is composed primarily of hydrogen (about 90%) and helium (about 10%), with traces of other gases such as methane, ammonia, and water vapor.
- Length of Day and Year : Jupiter has the shortest day of all the planets in the solar system, making a complete rotation around its axis in just 9 hours and 56 minutes. However, due to its enormous distance from the Sun, one year on Jupiter is equivalent to approximately 11.86 Earth years.
The Great Red Spot: A mystery in the atmosphere
One of the most recognizable aspects of Jupiter is its "Great Red Spot." This is a gigantic anticyclonic storm that has existed for at least 400 years. Although its size has decreased in recent decades, it is still large enough to house three Earths inside it.
The Great Red Spot has puzzled scientists for centuries because of its longevity and the forces that keep it moving. Storms on Earth typically dissipate within a few days or weeks, but the Great Red Spot has endured for centuries. This is thought to be due to the lack of a solid surface on Jupiter, meaning there is no significant friction to stop the storm.
In addition, Jupiter's atmosphere is structured into horizontal bands that circulate at different speeds and directions. These bands, together with the planet's rapid rotation, create extremely strong wind currents, which keep the storm active. Winds in the Great Red Spot can reach speeds of up to 432 km/h, making it one of the most powerful storms in the solar system.
Jupiter's ring system
Although not as prominent as Saturn's rings, Jupiter also has a ring system. These rings were discovered by the Voyager 1 spacecraft in 1979. Jupiter's ring system is much fainter and less extensive than Saturn's, and is composed mostly of small dust particles. These particles are thought to be the result of meteorite impacts on Jupiter's nearest moons.
Jupiter's ring system consists of three main parts:
- Halo Ring : This is the innermost ring and is made up of very fine particles.
- Main Ring : It is the brightest and is composed of larger particles.
- Gossamer rings : These are fainter, more diffuse rings that extend beyond the main ring.
Jupiter's gigantic magnetic field
Jupiter has the strongest magnetic field of any planet in the solar system. This field is about 20,000 times more powerful than Earth's, creating a huge magnetosphere that extends millions of miles beyond the planet. Jupiter's magnetosphere is so large that if it were visible from Earth, it would cover an area larger than the Sun.
This magnetic field traps charged particles, creating extremely intense radiation belts that surround the planet. These belts are dangerous for spacecraft, as the radiation can damage equipment and put astronauts at risk. However, they also generate spectacular auroras in Jupiter's polar regions, similar to the northern and southern lights on Earth, but much more intense.
Jupiter's moons
Jupiter is the planet with the most moons in the solar system. To date, 92 moons have been discovered orbiting the gas giant, although this number could increase as more are discovered. Some of these moons are small and irregularly shaped, while others are impressive celestial bodies in their own right.
The four largest moons of Jupiter, known as the Galilean moons, are:
- Io : Io is the most volcanically active body in the solar system. Io's volcanoes eject huge plumes of sulfur and sulfur dioxide, giving it a unique and colorful appearance.
- Europa : One of the most promising moons for the search for extraterrestrial life, it is believed to have an ocean of liquid water beneath its icy surface, which could provide the conditions necessary for life.
- Ganymede : Ganymede is the largest moon in the solar system, even larger than the planet Mercury. Ganymede has its own magnetic field, which is unique among the moons of the solar system.
- Callisto : One of the oldest and most heavily cratered moons in the solar system, its surface is covered in impact scars, providing clues about the early history of the solar system.
These Galilean moons were discovered by Italian astronomer Galileo Galilei in 1610, and their observation radically changed our understanding of the universe. Galileo was the first to observe that not everything in the solar system revolves around the Earth, which supported Nicolaus Copernicus' heliocentric theory.
Jupiter in human culture
Since ancient times, Jupiter has played an important role in the mythologies and cultures of various civilizations. The ancient Romans named it after their chief god, Jupiter, who was the Roman equivalent of Zeus in Greek mythology. To the Greeks, Zeus was the king of the gods, ruling over the sky and thunder, a fitting parallel for the largest planet in the solar system.
Jupiter has also been a fascination for astronomers for centuries. Early observers, such as Galileo, used rudimentary telescopes to observe Jupiter's moons, and their discoveries helped cement the idea that celestial bodies do not orbit Earth, but instead move around the Sun.
In the modern era, Jupiter has been studied by numerous space missions, from the Pioneer 10 and 11 probes in the 1970s to more recent ones such as Juno, which arrived at Jupiter in 2016. Juno has provided a wealth of information about Jupiter's internal composition, its magnetic field, and the dynamics of its atmosphere.
Curiosities about Jupiter
- Weight on Jupiter : If you could stand on Jupiter, you would weigh more than twice as much as you do on Earth due to its enormous gravity. A person who weighs 70 kg on Earth would weigh around 165 kg on Jupiter.
- Failed artificial satellite : In 2003, the Galileo probe, after more than eight years of studying Jupiter and its moons, was sent into Jupiter's atmosphere, where it disintegrated. NASA took this decision to prevent the probe from contaminating Europa, a moon that could harbor life.
- Asteroid Belt : Jupiter acts as a protective "shield" for Earth. Its enormous gravity deflects or captures many comets and asteroids that could impact Earth. For this reason, some scientists believe that Jupiter's presence has been crucial to the stability of the solar system and the development of life on Earth.
- Jupiter's atmosphere is deep : The upper layers of Jupiter's atmosphere are composed of clouds of ammonia and water, but as you descend, the pressure and temperature increase, turning the hydrogen into a metallic liquid. It's not known for certain whether Jupiter has a solid core, but current data suggest there may be a rocky core the size of Earth at its center.
Future missions and study of Jupiter
The study of Jupiter is far from over. In 2022, the European Space Agency (ESA) launched the "JUICE" (Jupiter Icy Moons Explorer) mission, which will reach Jupiter in 2030. This mission will focus on studying Jupiter's icy moons, especially Europa, Ganymede and Callisto, with the aim of searching for signs of geological activity and possible habitable environments.
Additionally, NASA's Europa Clipper mission is also scheduled to launch in the mid-2020s. This mission will closely investigate the moon Europa, with particular attention to its subsurface ocean and its potential to host life.