Perfectly visible to the unaided eye, Jupiter is the fifth planet from Sun. Jupiter is famous for its colossal size, a tapestry of colorful bands and swirls, strong gravitational pull, and turbulent storms. Read on to discover some interesting Jupiter facts.
Facts about Jupiter
1. Jupiter is the fifth planet from the Sun.
At its closest (perihelion), Jupiter is 741 million km (460 million miles) from the Sun. At its furthest (aphelion), Jupiter is just over 817 million km (508 million miles) from the Sun.
2. It takes 43.25 minutes (43 minutes and 15 seconds) for the Sun’s light to reach Jupiter.
In comparison, it takes 499 seconds (8 minutes and 19 seconds) for the Sun’s light to reach Earth.
3. Jupiter is the second brightest planet in the night sky, after Venus.
This makes Jupiter the third brightest natural object in the night sky after the moon and Venus. Chances are, you’ve already seen Jupiter in the night sky, but had no clue that’s what you were looking at 😉
4. Jupiter is one of the two so-called “gas giants.”
Along with its immediate neighbor Saturn, Jupiter has been classified as one of the two “gas giants.” A gas giant is a large planet that is not primarily composed of rock or other solid matter. Rather, the majority of its mass is in the form of gases like helium and hydrogen around a small rocky or metallic core.
Unlike terrestrial planets, which have a clearly defined difference between atmosphere and surface, gas giants do not have a well-defined surface as their atmospheres gradually increase in pressure toward the core.
As such, Jupiter doesn’t have a true surface and it isn’t possible to “land on” such planets. By volume, Jupiter is composed of 89.8% Hydrogen and 10.2% Helium with trace amounts of ammonia, methane, water ice aerosols, water, ethane, and hydrogen deuteride.
However, the use of the word “gas” is somewhat of a misnomer. As a result of the enormous pressures inside Jupiter, the majority of helium and hydrogen exists in liquid rather than gaseous form.
Despite being a massive ball of gas, you can’t fly through it like a cloud. The pressure is so strong that it would crush and vaporize any human-made spacecraft.
5. Jupiter is 2.5 times the combined mass of all the other planets put together.
One of the most well-known Jupiter facts is that it is the largest planet in our Solar System. But this is just putting it mildly. Jupiter is so colossal that even if the masses of all the other planets in our Solar System were combined into one big superplanet, it still would weigh half as much as Jupiter.
The mass of Jupiter is 318 times as massive as the Earth. Though it is significantly more massive than Earth, it is only a quarter as dense because it is made of gas rather than rock.
Furthermore, it would take almost 11 Earths lined up next to each to match Jupiter’s diameter.
6. If Jupiter got any more massive, it would get smaller.
Interestingly, accrual of additional mass would make Jupiter denser, which would cause it to start pulling it in on itself.
7. You could fit 1321 Earths inside Jupiter and still have room to spare.
The volume of Jupiter is 1.4313×1015 km3. The gas giant is so large that you could accommodate 1321.33 Earths inside Jupiter!
8. Jupiter is home to the largest ocean in the Solar System.
However, it’s not the kind of ocean you would want to go swimming in or sailing on. As mentioned earlier, the planet is mostly made of hydrogen and helium.
In the outer layer, these elements are gases, but deeper inside Jupiter, the gases are gradually crushed and become liquid. This is due to 295 million kilograms (650 million lbs) of pressure packing the hydrogen molecules together into that form.
At around 20,000 km (12,000 miles) deep, they become an electrically charged liquid called metallic hydrogen. This layer of metallic hydrogen may have a depth of as much as 40,200 km (25,000 miles).
By comparison, Challenger Deep, the lowest ocean depth on Earth, is only about 11 km (6.8 miles) deep.
9. Jupiter is named after the Roman god of sky and thunder.
Fittingly, Jupiter, the largest planet in the Solar System, is named after the King of the Roman gods.
10. Jupiter is the oldest planet in the Solar System.
One of the lesser-known facts about Jupiter is that it is the Solar System’s oldest planet. Jupiter’s rocky core started taking shape less than a million years after the beginning of our Solar System 4.6 billion years ago.
After Jupiter formed, the expanding planet accumulated a great amount of gas and dust as it circled the Sun. Within another 3-4 million years, that core grew to 50 times the mass of Earth.
11. Jupiter has the strongest gravitational pull of any planet in the Solar System.
At 24.79 m/s² Jupiter’s surface gravity is 2.53 times greater than Earth’s surface gravity of 9.8 m/s². This means that if you weighed 100 kg (220 lbs) on Earth, you would weigh a whopping 253 kg (558 lbs) on Jupiter.
12. Jupiter has the shortest day in the Solar System at 9.925 hours.
A day is defined as the amount of time it takes an astronomical object to complete one full spin on its axis. On its axis, Jupiter rotates at a speed of 12.6 km/s, which is extremely fast, especially considering how large Jupiter is. It also makes Jupiter the fastest spinning planet.
In comparison, the Earth only rotates at a speed of 0.46 km/s. Jupiter’s rapid spinning speed means that the length of a day on Jupiter is 9.925 hrs or 9 hours, 55 minutes, and 30 seconds.
13. Jupiter is the second flattest planet in the Solar System.
If you observe Jupiter, you’ll notice that it has a bit of a squashed appearance instead of being a perfect sphere. A variety of factors influence a planet’s flatness such as size, density, and spin, with lower density and faster spin causing a planetary bulge at the equator.
Jupiter’s low density (1,326 kg/m3) and fast rotational velocity (12.6 km/s) are the main reason why it has the second biggest equatorial bulge of all planets, after Saturn. Although all planets except Mercury and Venus exhibit ellipticity (flattening), Jupiter’s equatorial diameter is almost 7% greater than its polar diameter.
Jupiter’s equatorial bulge is 9,276 km (5,764 miles). In comparison, the Earth has a slight equatorial bulge of 42.72 km (26.5 miles), its equatorial diameter being about 0.3% greater than its polar diameter.
14. Jupiter emits more energy than it absorbs from the Sun.
Like the other Jovian planets (except Uranus), Jupiter emits more energy than it absorbs from the Sun. Jupiter radiates about 1.7 times as much heat as it receives from the Sun.
While there is no conclusive answer as to what is the source of Jupiter’s internal energy, it’s thought that much of this heat is residual heat left over from Jupiter’s gravitational collapse when it was formed.
15. A year on Jupiter is almost 12 Earth years.
While Jupiter rotates way faster than Earth on its axis, its orbital velocity is much slower (13.07 km/s as opposed to 29.8 km/s of Earth’s).
Its torpidity means it takes Jupiter a whopping 11.86 Earth years, or 4,333 Earth days, to make one trip around the Sun.
16. Jupiter is not a “failed star” and can’t become a star.
Jupiter is sometimes described as a “failed star” because it has a chemical composition that is very similar to that of a star. However, the term “failed star” is a misnomer as Jupiter was never at a mass level or even close to becoming a star.
True failed stars are brown dwarfs. They have masses between 13 and 80 times that of Jupiter and can support the fusion of deuterium (an isotope of hydrogen). Brown dwarfs don’t possess enough mass to sustain a true fusion reaction (a thermonuclear reaction that turns hydrogen into helium in its core) that defines a star.
Although Jupiter is rich in hydrogen and helium, it is too light, and its central temperature never got high enough for hydrogen fusion to start. Jupiter would need to be over 80 times its current mass to ignite nuclear fusion in its core to become a star.
17. On Jupiter, there are no discernible differences between the seasons.
Planets experience seasonal variations based on the degree of their axial tilt (the measure of the angle between the planet’s rotational axis and a line perpendicular to its orbital plane). The greater a planet’s axial tilt, the more pronounced the seasonal changes as it allows the sun to heat the planet’s surface at different times during the year.
While Earth’s axis is tilted 23.5 degrees, Jupiter’s axial tilt is only 3.13°. This lack of tilt means the planet’s surfaces receive a uniform amount of the Sun’s energy.
Though Jupiter experiences seasons, there is little change from one to the next. A season on Jupiter lasts for approximately three years because it takes the planet 11.86 years to complete one orbit around the Sun.
Despite its lack of seasonal variations, no other planet has weather patterns quite like Jupiter’s. Its atmosphere churns with colossal storms and is riddled with winds, lightning, and thunder, all of which are more powerful than anything experienced on Earth.
Surface winds on Jupiter can blow at over 600 kph (370 mph). and the planet experiences storms that can grow to thousands of kilometers in diameter in the space of a few hours.
18. Nobody knows who first discovered Jupiter.
If you’re wondering who discovered Jupiter, the problem is nobody really knows. No one can take credit for “discovering” Jupiter because it is easily visible to the naked eye and has been known since antiquity.
19. Jupiter’s magnetosphere is the largest and most powerful of any planetary magnetosphere in the Solar System.
One of the most mindblowing Jupiter facts is how large and powerful its magnetosphere is. Jupiter’s magnetosphere (the magnetic fields and the charged particles) is so big that it extends up to 5 million km (3 million miles) towards the Sun, and the magnetotail behind Jupiter is more than 1 billion km (600 million miles) long, sometimes stretching out beyond Saturn’s orbit!
If one could see Jupiter’s magnetosphere, it would appear two to three times the size of a full moon to viewers on Earth.
Electrical currents, driven by Jupiter’s speedy rotation within its liquid metallic shell, apparently generate the planet’s strong magnetic field. Jupiter’s magnetic field is 16-54 times more powerful than Earth’s magnetic field. It traps charged particles and accelerates their movement to incredibly high speeds.
20. Jupiter is home to the biggest storm in the Solar System that’s raged for at least the last 190 years called the “Great Red Spot.”
The giant oval storm in Jupiter’s southern hemisphere, the “Great Red Spot,” is the planet’s most distinctive feature. It is a colossal anticyclone whose first recorded observation dates back to 1831. For all we know, the storm has been swirling around for millennia.
The Great Red Spot’s crimson-colored clouds spin counterclockwise at speeds that exceed 644 kph (400 miles per hour). It has evolved in shape over time and though there are indications it may be shrinking in size, the Great Red Spot could still swallow the whole of Earth.
21. Jupiter is made up of bright stripes called “zones” and dark stripes called “belts.”
If you’ve seen pictures of Jupiter, you’ll have seen stripes across its surface. The upper layers of Jupiter’s clouds are laced with white ammonia ice and are organized into stripes called zones, which sit parallel to the planet’s equator.
When these clouds are absent, deeper layers of Jupiter’s atmosphere are exposed, resulting in darker bands called belts.
22. Although it is not visible in pictures, Jupiter is known to have four sets of rings.
One of the more surprising Jupiter facts is that this colossal giant has a system of faint planetary rings. Jupiter’s rings consist of four main segments – an inner torus of particles known as the halo, a relatively bright main ring, and two outer gossamer rings.
However, unlike Saturn’s rings which contain water ice, Jupiter’s faint, dark rings are composed of tiny rock fragments and dust.
23. To date, nine spacecraft have visited Jupiter.
Nine spacecraft have visited Jupiter since the 1970s. Launched in March 1972, Pioneer 10 was the first spacecraft to visit Jupiter when it flew by the gas giant in December 1973.
The next eight were Pioneer 11, Voyager 1, Voyager 2, Galileo, Ulysses, Cassini, New Horizons Mission, and Juno.
24. Jupiter is the planet with the second-most number of moons in the Solar System.
To date, a total of 79 moons (or natural satellites) of Jupiter have been discovered. Only Saturn has more moons. Out of these, 53 are officially named and 26 are provisional moons.
Provisional moons are those that haven’t been assigned a proper name and aren’t considered “real” moons until their discoveries are confirmed by additional observations.
Discovered by Italian astronomer Galileo Galilei in 1610, Jupiter’s four largest moons—Io, Europa, Ganymede, and Callisto, were the first objects in the Solar System found to orbit a planet other than the Earth. These four moons are among the most exciting moons in the Solar System and are known as “Galilean moons” (or “Galilean satellites”).
25. Jupiter’s moon Ganymede is the largest moon in the Solar System and is the only moon with its own magnetic field.
With a diameter of 5,268 km (3,273 mi), Ganymede is 26% larger in volume than the planet Mercury. though it only possesses about 45% of Mercury’s mass.
Ganymede is so big that it is the only moon in the Solar System known to have its own magnetic field.
Jupiter’s largest moon also has a saltwater ocean under its icy surface. This ocean of Ganymede has more water than all the water on Earth’s surface and is thought to be about 100 km (62 miles) thick, 10 times the depth of Earth’s oceans.
26. Jupiter’s moon Callisto is the most cratered object in the Solar System.
Jupiter’s second-largest moon Callisto is the most heavily cratered object in the Solar System. Similar in appearance to a golf ball, Callisto’s surface is covered almost uniformly with pockmarks and craters, evidence of relentless collisions.
27. Jupiter’s moon Io is the most geologically active object in the Solar System.
Whereas the Earth’s moon has been geologically inactive for eons, Jupiter’s innermost natural satellite Io holds the distinction of being the most volcanically active object in the Solar System. Io’s sulfurous landscape exhibits gigantic lava flows, fuming lava lakes, and high-temperature eruptions.
Io is home to over 400 active volcanoes that can produce streams of lava up to 400 km (250 miles) high, and even taller volcanic geysers that blast sulfurous plumes of epic proportions, sometimes reaching heights of 500 kilometers (310 miles) into space.
Unlike the Earth, whose volcanoes are energized by heat from radioactivity and friction due to mass motion, Io’s intense geological activity results from the heat produced by the gravitational tug-of-war between Jupiter and its other Galilean moons Europa and Ganymede.