What is Jupiter: Definition and 159 Discussions

Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth the mass of the Sun. Jupiter is the third-brightest natural object in the Earth's night sky after the Moon and Venus. It has been observed since pre-historic times and is named after the Roman god Jupiter, the king of the gods, because of its observed size.
Jupiter is primarily composed of hydrogen, but helium comprises one quarter of its mass and one tenth of its volume. It likely has a rocky core of heavier elements, but like the other giant planets, Jupiter lacks a well-defined solid surface. The on-going contraction of its interior generates heat greater than the amount received from the Sun. Because of its rapid rotation, the planet's shape is that of an oblate spheroid; it has a slight but noticeable bulge around the equator. The outer atmosphere is visibly segregated into several bands at different latitudes, with turbulence and storms along their interacting boundaries. A prominent result of this is the Great Red Spot, a giant storm that is known to have existed since at least the 17th century, when it was first seen by telescope.
Surrounding Jupiter is a faint planetary ring system and a powerful magnetosphere. Jupiter's magnetic tail is nearly 800 million km long, covering the entire distance to Saturn's orbit. Jupiter has almost a hundred known moons and possibly many more, including the four large Galilean moons discovered by Galileo Galilei in 1610. Ganymede, the largest of these, has a diameter greater than that of the planet Mercury.
Pioneer 10 was the first spacecraft to visit Jupiter, making its closest approach to the planet in December 1973. Jupiter has since been explored on a number of occasions by robotic spacecraft, beginning with the Pioneer and Voyager flyby missions from 1973 to 1979, and later by the Galileo orbiter, which arrived at Jupiter in 1995. In 2007, Jupiter was visited by the New Horizons probe, which used Jupiter's gravity to increase its speed and bend its trajectory en route to Pluto. The latest probe to visit the planet, Juno, entered orbit around Jupiter in July 2016. Future targets for exploration in the Jupiter system include the probable ice-covered liquid ocean of the moon Europa.

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  1. S

    B Can Jupiter gravitationally eject a pebble in orbit? A smaller mass?

    Is there a limit to the smallness for a larger mass to eject? Can a planet eject a grain in orbit, or even a lone atom in orbit?
  2. Strato Incendus

    Writing: Input Wanted Postulating Life on Jupiter's moon Europa

    Even an offhanded remark by some character in a sci-fi story can have major implications. With my story based on a generation ship in the late 25th century, I considered it self-evident that humanity would already have explored most of the planets and moons within the solar system before trying...
  3. Astronuc

    JUpiter ICy moons Explorer (JUICE) on it's way to Jupiter

    https://www.imperial.ac.uk/news/244571/imperial-led-jupiter-bound-instrument-successfully-deployed/ https://www.esa.int/Science_Exploration/Space_Science/Juice https://www.esa.int/Science_Exploration/Space_Science/Juice/How_to_follow_the_Juice_launch_live...
  4. Astronuc

    B Exoplanet TOI-4603 b, ~13x Jupiter mass, ~1.04 Jupiter diameter

    https://phys.org/news/2023-03-massive-giant-exoplanet-tess.html It is one of the most massive and densest exoplanets. For comparison, Mo has a density of 10.22 g/cm3 and Ta has a density of 16.6 g/cm3. I would suspect that some of the density is derived from the high compressive pressure of...
  5. Z

    Does Ceres ever transit Jupiter?

    Does Ceres ever transit Jupiter? And if it does, how large of a telescope would I need to see it?
  6. Lluis Olle

    B What if a needle hits Jupiter at nearly speed of light?

    This is much like the "grain of sand" at near speed of light hiting Earth, but now targeting Jupiter with a needle! What if... Any way, which is the correct way to analyze this kind of scenarios? For example, I think than being the speed of the needle near c, is nonsense to think about the...
  7. Dave Gungan

    I How to interpret this new Keck spectrum picture of Jupiter?

    Last night, on Wednesday, November 9, the KPF team successfully captured a first light spectrum of Jupiter with the next-generation instrument This spectrometer picture of Jupiter has just been taken by the Keck, but I don't understand it. Wiki says Jupter is "89%±2.0% hydrogen" and "10%±2.0%...
  8. neilparker62

    B Discover Jupiter's Mysteries with James Webb Space Telescope

    In case you didn't see it elsewhere:
  9. Astronuc

    I Jupiter atmosphere, turbulence and ocean fluid dynamics

    Ocean physics explain cyclones on Jupiter https://phys.org/news/2022-01-ocean-physics-cyclones-jupiter.html Moist convection drives an upscale energy transfer at Jovian high latitudes https://www.nature.com/articles/s41567-021-01458-y...
  10. A

    I In Freefall orbiting Jupiter versus Earth

    I know that in Earth, an astronaut feels weightless in orbit but actually is not. The astronaut would not feel his own weight until he actually stands on a floor where his feet point towards the Earth as the Normal Force is the perception of weight. So, in Jupiter, where g ~ 25, an astronaut...
  11. C

    I Composition of Jupiter: Ices, Cores & Outer Gas Layers

    Hello PF, I am teaching a general education college-level introduction to "Planet Earth" class that covers a bit of astronomy. This question is in regards to our unit on the formation of the Solar System. Specifically I am confused about the composition of Jupiter and Saturn. This is a figure...
  12. B

    I Jupiter appearing flashy - red on top, blue bottom

    Been noticing this for a few evenings; didn't know it was Jupiter until this evening using https://stellarium-web.org/ (image from this evening). Has been distinctly flashy more than other objects with a slight red flash at the top and a blue flash close to the bottom. Last night I looked with...
  13. xpell

    I If Jupiter had a 5th large moon until "recently", would we know?

    Hi! I'm fascinated by the apparent "concentration" of the four large Galilean moons in a barely 1.5 million km "strip", and the vast, "empty" distance to the next moons (moonlets?) Out of a purely aesthetic sense of horror vacui, :wink: I've always wondered if there was at least another Jovian...
  14. S

    B Jupiter's pole storms - potential relation?

    I just watched this beautiful video about resonance frequencies and saw a pattern (the pattern at 1:25) , that reminded me of the pole storms on jupiter: Image Credit: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRA Could it be that some resonance frequencies on the pole of Jupiter are the reason why...
  15. S

    I Ignite Jupiter? Could Earthlike Planets Exist in Its Atmosphere?

    Jupiter has large cold satellites, which could be Earthlike. Earth emits more energy than from the Sun from radioactive elements still decaying in the Earth's core. Jupiter also generates energy, perhaps low level thermonuclear activity. Jupiter has a magnetic field like the Sun does...
  16. fresh_42

    B Jupiter and Saturn in one frame

    https://phys.org/news/2020-11-december-jupiter-saturn-planet-middle.html I do not know if we have enough hobby astronomers here, but the above calls for a photo competition. But in any case, don't miss the opportunity if you're a stargazer!
  17. B

    B Does Jupiter have an angular momentum problem?

    I'm sure I've read somewhere that Jupiter has 99% of the solar system's angular momentum, which shouldn't be the case. However, I can't find a source for this, and any search online for the topic doesn't bring up any science sites. Did I mis-remember?
  18. A

    I Are stable orbits possible between Mars and Jupiter?

    Just quick question: Could you put space stations (or even other small planets) at any aribitrary orbit or any radius in between Jupiter and Mars? Or, if something attempted to do so, would the orbit be unstable, and the object drift to either Mars or Jupiter? I was reading about Lagrange...
  19. O

    I How does Jupiter protect the Earth from collision with space rocks?

    I read (in "The View From The Center") that Jupiter protects the Earth from collision with large space rocks, asteroids, etc. What I can't get out of my mind is that could it also cause collisions. A large rock (initially not heading for Earth) could be put on a different path by Jupiter's...
  20. K

    I Uncovering the Truth: Jupiter's Core Revealed as Solid Diamond by Tammy Ma

    In a recent Scientific American article, Tammy Ma claims Jupiters core is solid diamond. She claims her work with lasers has demonstrated this. Any thoughts?
  21. T

    B Conjunction Mars, Jupiter, Saturn, Moon - March 18 + or -

    Yup, they all appear together pre-dawn on March 18 to the SE. The planets hang out together for a week or so, while the Moon moves on. https://www.news4jax.com/weather/2020/03/16/you-are-missing-planet-palooza-if-you-dont-look-up-the-next-few-days/
  22. W

    B Why does Jupiter have a stronger gravitational pull than Earth?

    Objects fall on Earth at 9.8 m/sec² independent of mass. If gravity is independent of mass why does Jupiter pull an object more than the Earth does? Is that inconsistency within the law or in my perception?
  23. T

    B New Storms on Jupiter, by Juno spacecraft

    https://www.space.com/nasa-juno-dodges-death-jupiter-polar-storm.html Includes a video.
  24. F

    B Why Jupiter, Saturn and the Sun have a distinctive and sharp boundary?

    Pardon the very naive question, but why does the atmosphere in these gas giants seem to have, from a distance, a very clear, sharp and distinctive boundary? When one looks at Earth's atmosphere from space, it seems to have a fuzzy bluish boundary, gracefully vanishing into the black. I read...
  25. T

    B The Mysterious Shape of Jupiter: Why Gas Planets Stay Spherical

    If Jupiter is made of gas, how can it maintain its spherical shape without being contained in a spherical shaped container?
  26. Benjamin_harsh

    Will my wrist watch slow down on planet Jupiter?

    Does my wrist watch slows down on planet Jupiter? I know Jupiter's gravity is greater than Earth's gravity.
  27. D

    Does dropping a Jupiter from the Pisa tower still accelerate at g = 9.81?

    im confused about this thing, because they said Earth's acceleration due to gravity is independent from the mass of the thing dropped
  28. Sandeep T S

    I Speed of Light Measured by Jupiter's Moons: Error 26%?

    Romer measured speed of light using moon's of Jupiter but he got value with a error of 26%. Is anyone did same experiment in modern era? And what value they got?
  29. T

    B Brown Dwarf Mass Gain: Does Radius Increase?

    Why wouldn't a brown dwarf grow in radius if it started to gain mass?
  30. diogenesNY

    B NYTimes: 79 Moons of Jupiter and Counting

    By Kenneth Chang July 18, 2018 On Tuesday, scientists led by Scott S. Sheppard of the Carnegie Institution for Science announced the discovery of a dozen moons around Jupiter, bringing the total number orbiting the solar system’s largest planet to 79. Next to the famous moons that Galileo...
  31. A

    I Manned mission to Europa: science or still scifi?

    I ask because I feel a mission to Europa as something much more interesting than landing on Mars because of its obvious potential astrobiological implications. And I suspect that drilling through Europa's ice is never going to happen just by sending some sort of robotic drilling rig alone and...
  32. wolram

    B How did Jupiter and Saturn disrupt our solar system

    This article suggests that exoplanets are the same size and have equal orbital spacing ,so what is different from our solar system. https://www.sciencedaily.com/releases/2018/01/180109141918.htm An international research team led by Université de Montréal astrophysicist Lauren Weiss has...
  33. N

    Height of the image of Jupiter created by the objective lens

    Homework Statement I have the following variables: f = .93 m f(e) (eyepiece) = .0082 m distance toJupiter pj = 588 E^9 diameter of Jupiter dj = 139822 E^3 Find the height of the image of Jupiter created by the objective lens of a telescope. Homework Equations M = -q/p q = f Where M is the...
  34. Beth Doodle

    B Could a brown dwarf passing through our solar system ignite Jupiter?

    First let me make clear that I am not a student in Physics. I have a BA in Anthropology and a BS in Computer Science. My only background in Astronomy and Astrophysics is as a fan. The sort that has watched lots of Discovery Channel-likeTV shows over the years. I'm now 61. The reason that I...
  35. C

    B Radar & Jupiter Great Red Spot

    Ever since the first Pioneer spacecraft sent back closeup photos of Jupiter's Great Red Spot ("GRS") back in 1978(?), I noticed the GRS looks like a wave-cloud. There is a thick lip of wave-cloud on one side of the GRS, caused by air sweeping over an enormous volcano, it then bends around on...
  36. Oganesson

    I Is Jupiter too big to orbit the Sun?

    I read the Jupiter is so big that it doesn't really orbit the sun. Is that true?
  37. D

    New orbit of satellite deflected by Jupiter

    Homework Statement This question involves parts of other questions, so I will state the relevant parts and essentially what the question is asking. It is from Kibble Classical Mechanics, Chapter 4, Question 22. If more information is needed I will provide. We have a satellite that orbits the...
  38. Omega0

    B Jupiter Red Spot Position and more

    Hi, I would be interested in the position and the "appearing" of Jupiters red spot over many decades. Here the first question is: What would be the best coordinate system? Jupiters axis of rotation is very stable. So the latitude would be very interesting in my eyes. But: How do we define the...
  39. 1oldman2

    B Discussing Juno/JunoCam Mission and Jupiter Data

    With the upcoming rendezvous of the Juno spacecraft and Jupiter I would like to begin this thread as a place for discussion on the variety of topics this mission is sure to produce. The instrument payload and orbital profile should produce a great amount of Data that will rewrite a lot of what...
  40. W

    Finding Jupiters Mass with one of its Moons

    Homework Statement One of Jupiters Moons runs on a circle with the radius r1= 420000km in T1=1,77d. How big is Jupiters Mass? Can you calculate the Mass of the Moon with this as well? γ = 6,672*10-11m3*kg-1*s-2 (gravitational constant) Homework Equations I used following equation...
  41. russ_watters

    Stargazing Amateurs Discover Asteroid Impacting Jupiter

    Two amateur astrophotographers in Europe separately photographed what appears to have been an asteroid impacting Jupiter, at least one using a low-intermediate level telescope: http://www.foxnews.com/science/2016/03/29/did-asteroid-slam-into-jupiter.html?intcmp=hphz06 Confirmation pending...
  42. Nivek Writer

    Is nuclear fusion of Jupiter possible?

    Hello everyone, I have a question about nuclear fusion. The simplest form of nuclear fusion is the fusion of 4 hydrogen atoms into 1 helium atom. Jupiter has a mass close to 1.9 * 1027 kg and around 90% of its mass consists out of hydrogen -> 0.9 * 1.9 * 10 27 = 1.71 * 1027 kg. I know that it...
  43. I

    Corotation speed and energy

    Homework Statement Hi! I need help with a problem regarding the corotational speed en energies for oxygen ions around Jupiter. I'm stuck Homework Equations See below The Attempt at a Solution I know that the maximum magnetospheric plasma density is about 1000-50000 cm^-3. I also know that...
  44. M

    How to find the speed of a planet around the sun

    Homework Statement THe sun has a mass of 1.99x10*30 kg. Jupiter has a mass of 1.90x10*27 kg and a mean radius of orbit around the sun of 7.78x10*8 km what is the speed that Jupiter travels in its orbit around the sun? Homework Equations fg=(Gm1m2)/d*2 fc=(4pie*2mr)/T*2 The Attempt at a...
  45. H

    Does Jupiter have precession of the equinoxes?

    I would think that precession of the equinoxes occurs only if the planet is at least partially rigid. Since Jupiter is gas and liquid, it would not experience precession of the equinoxes. Is this right?
  46. I

    Earth's orbit & precession affected by Venus & Jupiter?

    I watched a program that said that some of Earth's past climate change was due to variations in Earth's orbit and precession due to the the gravitational perturbations caused by Venus and Jupiter. Why would that be so? I know that the orbits of the planets are eliiptical generally and they...
  47. Haley Feider

    How do you compute an average mass for Jupiter?

    Homework Statement Io and Europa are two of Jupiter's moons. Io orbits Jupiter at a distance of 421,000 km in a time of 1.769 days. Europa orbits Jupiter at a distance of 671,000 km in a time of 3.551 days. Compute an average mass for Jupiter. Homework Equations a=v^2/r...
  48. Nathanael

    Time between farthest and closest distance from Jupiter

    1 Jupiter year is 11.86 Earth years. The rate of change of the Earth-Sun-Jupiter angle is the difference between Earth and Jupiters angular speeds: ##\frac{1}{365}\big(1-\frac{1}{11.86}\big)\frac{\text{revolutions}}{\text{day}}## The time between the closest and farthest distances between...
  49. 1977ub

    Guidelines for including "atmosphere" in a body's "diameter"

    When we see an official description of Pluto's "diameter" it is given without the atmosphere. The official diameters of the gas giants seem to include many layers of gaseous atmosphere. Is this difference merely a convention? Or is there a good reason for treating e.g. Pluto differently than...
  50. A

    How much energy radiates from Jupiter?

    How much energy radiate Jupiter? I tried to find it, but not found. And how much energy it receive from Sun?