Jupiter is the largest planetary body in the solar system and sustains 95 known moons[4] within its gravitational pull. The gas giant has 3 layers of rings, a vast and powerful magnetosphere that stretches out into space beyond Saturn and is about 300 times more massive than Earth. Jupiter interacts heavily with the objects in our solar system, helped to form the asteroid belt, and influences (mostly deflects) comets away from our rocky ocean home world. There is extraordinary intricate history within the Jovian system; many of the moons have large amounts of craters and impact histories that could teach us about the origins of Earth and its ability to sustain life.
Jupiter completes a rotation once every 9.93 hours on average(the poles rotate slower than the equator) and takes 11.86 years to complete an orbit around the sun.
Jupiter’s diameter is 142 984 km, about 11 times that of the Earth (12,756 kilometers = Earth’s Equatorial radius).
The orbital characteristics of Jupiter are fairly circular with an aphelion 817 million km and a perihelion of 740 million kilometers, giving the planet an orbital eccentricity of 0.0487 (this is also known as the ellipse of the planet).
Jupiter’s has a slight orbital obliquity, about 3%, which means that it is slightly tilted on its side. It also has an orbital inclination of 1.3 degrees, meaning that the orbit itself is tilted just slightly from flat; many scientists believe that the inclination could increase substantially over the next billion years due to the moons of Jupiter and their gravitational pull. Especially when compared to the other planets, the orbit is pretty regular and very flat at least as far as we can tell during the current epoch, or conditions we observe.
Jupiter is shrinking 3cm each year due to the pressure of its own gravity, described by the Kelvin-Helmholtz mechanism. Its also cooling 1 degree Kelvin every million years. This is because of Jupiter’s distance from the Sun, its enormous size, and the composition of mostly Hydrogen and Helium in the largest planet’s atmosphere.
Jupiter’s Ancient Mythology
The chief deity of ancient Roman religion[3], Jupiter has been studied and documented for centuries, since the beginning of writing with the Babylonians around 400 BCE where they used calculus to find the position and chart the velocity of the gas giant planet[5]. They worshiped several deities associated with the planet, including Marduk and Sulpae. The Sumerians also documented the solar system on clay tablets using cuneiform writing and drawings more than 3,000 years before ancient Greek astronomers began their observations.
Jupiter’s cosmological history
The sun formed, then Jupiter followed. Exactly how this process happens is a big mystery, but scientists think it could happen with gravitational waves from supernova.
After the sun was formed, remaining gas and rock and debris from the stellar disc created Jupiter; the large gas giant was probably the first planet to form[8].
The Grand Tack Hypothesis is a leading theory addressing its early migration and influence on planetary formation and involves the core accretion model which occurs in two stages:
1. Core Formation:
• Jupiter likely formed in the protoplanetary disk of gas and dust that surrounded the Sun after the sun’s ignition.
• Initially, a rocky/icy core (hypothetical) formed through the accretion of planetesimals.
• Estimates suggest the core reached a mass of ~10 Earth masses before it could efficiently attract gas.
2. Gas Accretion:
• Once the core grew sufficiently massive, it gravitationally attracted hydrogen and helium gas from the disk, forming an extensive atmosphere.
• Jupiter’s rapid growth phase likely took place within the first few million years after the Sun’s formation, consistent with observed protoplanetary disk lifetimes (~1–10 Myr).
The Grand Tack Hypothesis (2011)
Primary Researchers:
- Kevin J Walsh – Southwest Research Institute (SwRI), Boulder, Colorado.
- Dr. Alessandro Morbidelli – Observatoire de la Côte d’Azur, Nice, France.
- Dr. Sean N. Raymond – Laboratoire d’Astrophysique de Bordeaux, France
- Dr. David P. O’Brien – Planetary Science Institute, Tucson, Arizona.
- Dr. Avi M. Mandell – NASA Goddard Space Flight Center, Greenbelt, Maryland.
A lot of what we know about Jupiter comes from watching stellar accretion in other systems. Ongoing observations of exoplanetary systems and advances in computational modeling continue to refine our understanding of these processes.
There are two phases of the proposed Grand Tack Hypothesis
1. Inward Migration (“Tack”):
• Jupiter formed at ~3–5 AU from the Sun.
• Gravitational interactions between Jupiter and the protoplanetary disk caused it to migrate inward.
• Numerical simulations suggest that Jupiter could have moved as close as 1.5 AU, disrupting the distribution of planetesimals and halting the formation of super-Earths near the Sun.
2. Outward Migration:
• As Saturn formed and reached ~30% of Jupiter’s mass, their gravitational resonance caused the two planets to migrate outward together. This process is known as type II migration in a viscous disk.
• Jupiter stabilized at its current position (5.2 AU).
Astrophysical Mechanisms:
• Jupiter’s migration was governed by torques exerted by the gas disk.
• Interactions between the gas giants (Jupiter and Saturn) caused the reversal of Jupiter’s inward migration.
The Impacts of Jupiter’s Migration on the Solar System:
Impacts on the Solar System
1. Asteroid Belt Structure:
• The Grand Tack explains the asteroid belt’s dichotomy:
• Inner belt: dry, rocky asteroids.
• Outer belt: water-rich asteroids.
• Jupiter’s migration redistributed material, scattering planetesimals and forming the mixed asteroid belt observed today.
2. Terrestrial Planet Formation:
• Jupiter’s inward migration truncated the inner disk, depleting it of material that might have otherwise formed super-Earths.
• This facilitated the formation of smaller terrestrial planets (Mercury, Venus, Earth, Mars).
• Numerical simulations show that the truncated disk could account for Mars’ relatively small mass compared to Earth and Venus.
3. Outer Solar System:
• The outward migration of Jupiter and Saturn influenced the formation of Uranus and Neptune, possibly scattering planetesimals into the Kuiper Belt and Oort Cloud.
Jupiter’s Planetary Properties
| Orbit Duration | 4,333 days | 11.86 years |
| Length of Day | 9.9259 hours |
| Rotational Speed | 12.6 km/s |
| Mass | 1.898 x 1026kg |
| Mean Density | 1,326kg/m3 |
| Mean Orbital Velocity | 13.06km/sec |
| Volume | 1.4313 x 1015km3 |
| Gravity at Sea Level (1 bar of pressure) | 25.92 m/s2 |
| Escape Velocity | 59.5km/s |
| Equatorial Diameter / Radius | 142,984 km | 88,846 mi / 71,492km | 44,423 mi |
The Gas Giant’s Chemical Composition
Jupiter spins at an alarming rate, which vastly contributes to its storms and atmospheric tumult. Its atmosphere is chaotic and ruled over by its incredible speed of rotation and enormous gravity.
Mostly Jupiter is composed of Hydrogen and Helium:
Molecular hydrogen (H2) – 89.8%;
Helium (He) – 10.2%;
and some other molecules: Methane (CH4); Ammonia (NH3); Hydrogen Deuteride (HD); Ethane (C2H6); Water (H2O) (varies with pressure) and Ammonia ice, water ice, ammonia hydro-sulfide.
Underneath the highly turbulent atmospheric layers there is a metallic hydrogen mantle that is electrically conductive and may give rise to the massive vertical storms that are visible on the poles of the planet. The core is believed to be composed of fuzzy, metallic hydrogen that is both solid and liquid but perhaps at the very center there is some more exotic form of hydrogen; the amount of pressure and heat at the core is tremendous at 4,000 GPa and 20,000 Kelvin.
The core of Jupiter is still very much a mystery and leaves tremendous room for exploration of chemical compositions of exotic elements including metallic hydrogen and other superconducting chemical states. This understand could power some extremely advanced technologies.
The Great Red Spot
The GRS (Great Red Spot) is one of the most unique features of the solar system. It is a massive 500 kilometer height high pressure system known as an anti-cyclonic storm in Jupiter’s southern atmosphere. It is a persistent storm that has existed for centuries and is one of the reasons that researchers believe Jupiter does not have a solid surface.
The image below show the retrograde motion of the storm as seen by Voyager 1, built in 1977 and is now the most distant human made object.
By NASA – This image or video was catalogued by Jet Propulsion Laboratory of the United States National Aeronautics and Space Administration (NASA) under Photo ID: PIA02855., Public Domain, Link
The GRS’s distinctive reddish hue is still a topic of study. Hypotheses include:
Chemical reactions involving ammonia, acetylene, and other compounds in Jupiter’s upper atmosphere.
Exposure to solar ultraviolet (UV) radiation, which alters the coloration of these chemicals.
The wind speeds reach up to 400km/h and is powered from convective heat and energy upwelling in the planetary atmosphere. The GRS is sustained by the lack of frictional forces and its interactions with surrounding jet streams. Jupiter’s atmosphere supports long-lived vortices due to its rapid rotation and stratified layers.
The GRS has been shrinking steadily since its discovery, and scientists can’t really explain why; they are unsure whether the GRS will eventually disappear or stabilize at a smaller size
Jupiter’s Magnetosphere
Jupiter’s magnetosphere is generated by a dynamo effect in its metallic hydrogen layer. Rapid rotation and the presence of electrically conducting material create the magnetic field.
Jupiter’s magnetosphere is shaped by the solar wind, extending up to 100–150 R_J (Jovian radii, 1 R_J = 71,492 km) on the nightside and compressed to ~45 R_J on the dayside.
The Magnetosphere (the region inside of the magnetopause, where the solar wind balances with Jupiter’s atmospheric particles) is filled with plasma from Io’s volcanic activity, which emits 1 ton of sulfur dioxide per second; it forms an ionized plasma torus. Jupiter’s rapid rotation pushes plasma outwards and drives its magnetic field creating high energy electrons and ions that spiral and emit synchotron radiation. In combination with the solar wind, this creates a bow shock and auras that spiral out into space. Jupiter is an extreme environment the likes of which do not exist on Earth.
Jupiter’s Moons
Jupiter has 95 moons and counting, as well as thousands of orbiting objects. Many of the moons aren’t named yet including many objects that have peculiar orbital patterns, atmospheres, and that shepherd Jupiter’s ring.
There are 4 moons that were discovered by Galileo in 1610: Io, Europa, Ganymede, and Callisto. Europa is a likely candidate for life in the outer solar system, as it has the potential for subterranean oceans! Europa Clipper, the NASA mission will get there in April, 2030.
Ganymede is the largest moon in the solar system and is slightly larger than Mercury; it also has a strong magnetic field, tectonic activity, impact craters, and is in a resonant orbit with Europa and Io.
Europa has evidence of a thin atmosphere that is created and is heavily affected by the gravitational presence of Jupiter. Its magnetic field gets disrupted when it experiences these strong tidal forces and causes the outer shell of ice and crust to flex, which likely contributes to its volcanic activity. They think this means there is an ocean of saltwater beneath a rocky crust.
Io is Jupiter’s 3rd largest moon and is considered the most volcanically active world in the solar system. It has hundreds of giant volcanoes that shoot miles into the sky. It has been like this for billions of years, producing magma from the stretching and squeezing of orbiting Jupiter. Io has an ultra bright plasma torus created by its volcanism, which is made of ionized oxygen electrons and sulfur. Io has a unique gravitational pattern, governed by the activity of the other moons, Europa and Ganymede.
Callisto is Jupiter’s second largest moon, almost as large as Mercury. It is heavily cratered and believed to be one of the oldest objects in our solar system. Callisto may also have a salty subterranean ocean, but it does not have volcanic activity, make it less likely for life. It’s an extremely old object, so its possible that the core has been inactive for a while.
There are 91 other moons. Their orbital properties are fascinating.
Jupiter’s Rings
Jupiter has a ring system, but its is not very reflective and can only be seen in front of the sun. The ring is a cloud of dust and ice and is shepherded by several of the moons, including the two small moons Adrastea and Metis orbit here within the main ring and are thought to be the source of dust of the main ring.[10]
Inside of the main ring there is a halo that is caused by electromagnetic forces as they can push small grains out of the ring plane.
The Gossamer rings are furthest from Jupiter and are also composed of dust from the nearby shepherd moons. The gossamer rings extend out pretty far into space.
The rings are most likely moon particles, in combination with materials that were present when the solar system formed. It isn’t completely known yet, which is why there is tons of room for missions to Jupiter!
A Future Destination for Deep Space Mining?
Jupiter is perhaps the best destination for mining outer space. Second perhaps, to Ceres, the largest asteroid. Mars is closer, but has less resources. I would be interested in that discussion so feel free to comment or reach out about it! As hydrogen fusion and solar power drive future energy needs, humanity will need to venture further into the solar system to harvest water, precious materials, and metals.
There is a lot of metal in the asteroid belt. Undoubtedly, some of Jupiter’s 95 moons has large amount of precious metal ores and if our mining capabilities were amped up we could send automated missions. Jupiter is also an excellent location for housing a satellite base, which could then send missions out into the asteroid belt.
Jupiter perturbs the asteroid belt as it rotates slightly slower than most asteroids due to its distance. It would also be a great addition to Mars to housing interplanetary life, when we get to that point. But it could also be a great base to bring minerals and heavy objects back from the asteroid belt due to Jupiter’s massive gravity. The Lagrangian Points are likely the best places to put a satellite, or orbit base so that it doesn’t have to contend as much with Jupiter’s massive gravity.
Current & Future Jupiter Missions:
NASA’s Juno mission – Juno has been in orbit around Jupiter since 2016 and plans to decommission in 2025. It probes beneath the cloud cover of Jupiter to understand the dynamic atmospheric composition and investigate the environment. So far, it has uncovered radiation belts, lightning, cyclones, and aurora features at the poles.
Europa Clipper – Europa Clipper is expected to arrive in 2030 and will do close to 50 flyby’s of Jupiter’s Moon Europa, which is the best candidate for supporting life currently known. It contains 9 science instruments, including cameras, thermal emission imaging, Ultra-violet spectroscopy, magnetometers and radio measurement devices. The data will be extremely interesting, so look forward to the mission’s success!! It launched on a Space X Falcon Heavy.
Juice – Jupiter Icy Moons Explorer should launch in 2031 and will study Jupiter’s 3 largest moons specifically for habitability.
Shensuo – a Chinese mission that will launch in 2026 and flyby Jupiter on its way to explore the heliosphere
Tianwen-4 – a Chinese mission that will orbit Callisto
Also I need to give a shout out to the voyager missions, which first imaged Jupiter and are still traveling out into the void.
Conclusion
The Jovian system, specifically the giant ball of gas that we know as Jupiter is an incredibly fascinating place. The amount of moons, the interstellar gravity trapped objects, and the dynamics of gravitation are all a giant laboratory for humankind to explore and most of all, learn about our origins. The Earth is part of a vast system of calm; somehow, we are relatively shielded from the cosmos and Jupiter’s properties are undoubtedly a huge factor in this calm sea of cosmic bliss that we exist in. From the origin of the system, to the vast amount of energy it produces and attracts, Jupiter could tell us so much about ourselves as we continue to explore the cosmos. Future space missions for the potential habitability of the planet will be extremely important as our species progresses to support multi-planetary life, and beyond.
References:
- Jupiter: The Planet, Satelites, and Mangetosphere by Fran Baegnal, Timothy Dowling, and William Mckinnon
- NASA – Jupiter’s Moons
- Wikipedia – Jupiter
- JPL Horizons – Planetary Satelite Ephemerides
- abc.net.au – Ancient Babylonian astronomers used calculus to find Jupiter 1,400 years before Europeans
- Astrobiology at NASA – Jupiter’s “Grand Tack” Reshaped the Solar System
- Original Grand Tack Hypothesis Paper – A low mass for Mars from Jupiter’s early gas-driven migration
- Jupiter may have been the second planet to form – By Lisa Grossman
- NASA – Europa
- rmg.co.uk – Jupiter’s Shepherd Moons