Jupiter is approximately 1.3 times larger than Saturn in diameter and nearly three times greater in volume. This makes Jupiter the largest planet in our Solar System, significantly surpassing its closest rival — Saturn — in size.
Understanding how many times Jupiter is bigger than Saturn helps to better grasp the differences in their physical characteristics and structure. Despite their similarity in composition and classification as gas giants, these two planets differ in size, mass, and internal makeup, which affects their gravitational fields, atmospheres, and magnetospheres.
In this article, we will take a detailed look at the size and volume comparison of Jupiter and Saturn to explain why Jupiter ranks first in size among the planets. For a deeper understanding of the atmospheric conditions and temperature peculiarities of these giants, we recommend our analysis “Jupiter and Saturn: Temperature, Causes, and Atmospheric Features.”
| Parameter | Jupiter | Saturn |
|---|---|---|
| Equatorial Diameter | 139,822 km | 116,464 km |
| Mass | 1.898×10²⁷ kg | 5.683×10²⁶ kg |
| Average Density | 1.33 g/cm³ | 0.69 g/cm³ |
| Flattening | 0.06487 | 0.09796 |
| Rotation Period | 9 h 56 min | 10 h 33 min |
- 139,822 km equatorial diameter of Jupiter
- 116,464 km equatorial diameter of Saturn
- 1.898×10²⁷ kg mass of Jupiter
- 5.683×10²⁶ kg mass of Saturn
- 0.09796 flattening of Saturn
What Are the Diameters of Jupiter and Saturn and How Much Do They Differ?
Planet Diameters
Jupiter’s equatorial diameter is about 139,822 kilometers, while Saturn’s is around 116,464 kilometers. These figures were obtained using measurements from NASA spacecraft missions, including Juno for Jupiter and Cassini for Saturn, ensuring high accuracy in modern mapping of the gas giants’ sizes.
Size Ratio
Jupiter exceeds Saturn in diameter by roughly 20%. This ratio confirms that although both planets are gas giants, Jupiter is noticeably larger, which is reflected not only in diameter but also in mass and volume. This difference is important for understanding their gravitational influences and the dynamics of the Solar System.
- Diameter of Jupiter: 139,822 km
- Diameter of Saturn: 116,464 km
- Jupiter is about 20% larger in diameter than Saturn
- Measurements made using NASA’s Juno and Cassini spacecraft
What Are the Volume Differences Between Jupiter and Saturn and How Do They Affect Comparisons?
Volumes and Formulas
Jupiter’s volume is approximately 1.43×10¹⁵ cubic kilometers, whereas Saturn’s volume is about 8.27×10¹⁴ cubic kilometers. Thus, Jupiter’s volume is almost 1.73 times greater than Saturn’s. The volumes of both planets are calculated using the ellipsoid volume formula, taking their flattening into account, which reflects the real geometry of the gas giants rather than an ideal sphere.
Practical Importance of Volumes
The volume difference impacts planet comparisons not only in scale but also in understanding their internal structures and atmospheres. For example, Jupiter’s larger volume combined with similar mass affects its density and gravitational field. This is crucial for modeling atmospheric dynamics and planning space missions, considering differences in gravitational pull and composition.
- Volume of Jupiter: 1.43×10¹⁵ km³
- Volume of Saturn: 8.27×10¹⁴ km³
- Volume ratio: about 1.73
- Flattening factored into calculations for accurate geometry assessment
Why Does Jupiter Significantly Outweigh Saturn in Mass and Density Despite Similar Sizes?
Planet Masses
Jupiter greatly surpasses Saturn in mass, having about 1.898×10²⁷ kg, which is more than 3.3 times the mass of Saturn — 5.683×10²⁶ kg. Meanwhile, Saturn’s mass is roughly 30% of Jupiter’s, despite their similar sizes.
This difference is explained by Jupiter containing far more heavy elements and gas, increasing its total weight. Additionally, Jupiter’s stronger gravity allows it to retain denser layers of material within its interior.
Density and Internal Structure
Jupiter’s average density reaches 1.33 g/cm³, nearly twice Saturn’s density of 0.69 g/cm³. This relates to internal structure: the pressure in Jupiter’s core is significantly higher, causing compression of materials and increasing density.
- Jupiter: core pressures reach hundreds of gigapascals, compressing hydrogen into a metallic state.
- Saturn: lower internal pressure results in less compression and thus lower density.
Therefore, the mass and density differences between Jupiter and Saturn arise from both composition and physical conditions inside the planets, leading to Jupiter’s more massive and denser state despite similar dimensions.
What Shape Features of Jupiter and Saturn Affect Their Sizes and Volumes?
Planetary Flattening
Jupiter and Saturn exhibit noticeable differences in shape, expressed in their flattening values: Jupiter’s flattening is 0.06487, while Saturn’s is 0.09796, indicating a more pronounced equatorial bulge on Saturn. This means Saturn’s equatorial diameter is relatively larger compared to its polar diameter than Jupiter’s. These flattening values were derived from image and measurement analyses by the Cassini mission for Saturn and Juno mission for Jupiter, conducted in the 21st century.
Effect of Rotation
The rapid rotation of the planets around their axes is a key factor shaping their flattening. Saturn spins slightly slower than Jupiter, with a rotation period of about 10 hours 33 minutes compared to Jupiter’s approximately 9 hours 56 minutes. Despite slower rotation, Saturn has greater flattening due to its lower density and more gaseous structure. Rotation generates centrifugal forces that expand the equatorial region, increasing the equatorial diameter of the planets and impacting their overall volume and shape.
When Can Comparing Jupiter and Saturn’s Sizes Be Misleading?
Comparison Limitations
Comparing Jupiter and Saturn’s sizes by diameter alone can be misleading, as this parameter does not consider mass and density, which differ significantly. Jupiter’s diameter is about 139,820 km, while Saturn’s is around 116,460 km, but Jupiter’s mass is nearly 3.3 times greater, highlighting substantial differences in internal composition and gravitational field.
Moreover, the volume calculated from radii does not reflect differences in density and atmospheric and core structure. Jupiter, with a larger volume of about 1.43×1015 km³, has a denser core and is more massive than Saturn, whose volume is about 8.27×1014 km³, despite their visual size similarity.
Role of the Atmosphere
Measurements of the visible radius of Jupiter and Saturn do not account for seasonal and atmospheric variations that can alter planet sizes by several hundred kilometers. For example, atmospheric winds on Saturn reach speeds up to 1800 km/h, affecting the shape and radius of the planet in the equatorial region.
For a comprehensive understanding of atmospheric conditions and their impact on planet sizes, we recommend the review “Jupiter and Saturn: Temperature, Causes, and Atmospheric Features,” which examines temperature gradients and gas composition that determine the planets’ appearance and radius in different seasons.
Frequently Asked Questions
How many times bigger is Jupiter than Saturn in diameter?
Why is Jupiter heavier than Saturn despite similar sizes?
How does planetary flattening affect their sizes?
Is it accurate to judge planet sizes by diameter alone?
Key Takeaways
- Jupiter is 20% larger than Saturn in diameter
- Jupiter’s volume is nearly 1.73 times that of Saturn
- Jupiter’s mass is more than three times that of Saturn
- Flattening and rotation speed influence planetary shape
- Volume and mass are more important than diameter for understanding sizes