We have clocked the wind speeds at about mph. The structure is about twice the size of Earth. Jupiter radiates more energy to space than it receives from the Sun. At Jupiter's orbital distance from the Sun, it should have a temperature of about Kelvin at the cloud tops, if it was radiating energy at the same rate that it received energy from the Sun.
However, the temperature is measured to be about Kelvin instead. Energy emitted by a planet is proportional to the fourth power of temperature, so a large difference in energy results from a small difference in temperature. We calculate that Jupiter radiates about twice the energy that it receives from the Sun. This energy must be coming from Jupiter itself. What is the source of this energy?
We believe it is leftover heat of formation of the planet still escaping to space. This schematic of Jupiter's interior is currently our best guess of what lies inside the giant planet. Jupiter is made of mostly hydrogen, the most abundant kind of normal matter in the universe.
Underneath the brightly colored cloud bands lies a thick layer of liquid metallic hydrogen. When hydrogen is under a great deal of pressure, the electrons can become unbound from the protons. When this happens, hydrogen can conduct electricity, as the electrons are free to flow. The rotation of this metallic hydrogen layer is believed to give rise to Jupiter's powerful magnetic field. This is an artist's depiction of the Juno spacecraft, which is currently orbiting Jupiter.
Unlike the inner terrestrial planets, Jupiter is a ball of almost entirely hydrogen and helium. Unlike Mars or Mercury, Jupiter has no surface features that you track to measure the rotation speed; there are no craters or mountains that rotate into view after a specific amount of time.
Jupiter has the fastest rotation of all the planets in the Solar System. Instead of being a perfect sphere, Jupiter looks more like a squashed ball. The bulge at the equator is even visible in small, backyard telescopes. This means Jupiter spins nearly upright and does not have seasons as extreme as other planets do.
With four large moons and many smaller moons, Jupiter forms a kind of miniature solar system. Jupiter has 53 confirmed moons and 26 provisional moons awaiting confirmation of discovery. Moons are named after they are confirmed.
Jupiter's four largest moons — Io, Europa, Ganymede, and Callisto — were first observed by the astronomer Galileo Galilei in using an early version of the telescope. These four moons are known today as the Galilean satellites, and they're some of the most fascinating destinations in our solar system. Io is the most volcanically active body in the solar system. Ganymede is the largest moon in the solar system even bigger than the planet Mercury.
A liquid-water ocean with the ingredients for life may lie beneath the frozen crust of Europa, making it a tempting place to explore. Discovered in by NASA's Voyager 1 spacecraft, Jupiter's rings were a surprise, as they are composed of small, dark particles and are difficult to see except when backlit by the Sun.
Data from the Galileo spacecraft indicate that Jupiter's ring system may be formed by dust kicked up as interplanetary meteoroids smash into the giant planet's small innermost moons. Jupiter took shape when the rest of the solar system formed about 4. Jupiter took most of the mass left over after the formation of the Sun, ending up with more than twice the combined material of the other bodies in the solar system. In fact, Jupiter has the same ingredients as a star, but it did not grow massive enough to ignite.
About 4 billion years ago, Jupiter settled into its current position in the outer solar system, where it is the fifth planet from the Sun. The composition of Jupiter is similar to that of the Sun — mostly hydrogen and helium. Deep in the atmosphere, pressure and temperature increase, compressing the hydrogen gas into a liquid. This gives Jupiter the largest ocean in the solar system — an ocean made of hydrogen instead of water.
Scientists think that, at depths perhaps halfway to the planet's center, the pressure becomes so great that electrons are squeezed off the hydrogen atoms, making the liquid electrically conducting like metal.
Jupiter's fast rotation is thought to drive electrical currents in this region, generating the planet's powerful magnetic field. It is still unclear if deeper down, Jupiter has a central core of solid material or if it may be a thick, super-hot and dense soup. It could be up to 90, degrees Fahrenheit 50, degrees Celsius down there, made mostly of iron and silicate minerals similar to quartz.
The planet is mostly swirling gases and liquids. Now that the model in this paper has demonstrated magnetic braking can lead to about the right spin rate for Jupiter and Saturn too , Batygin hopes future work will explore more meticulous aspects of the problem related to magnetohydrodynamics MHD , both with an analytic approach like with the equations in this paper and also simulations which were not used directly in this model.
The astrophysicists living on Jupiter or gas giant exoplanets in other star systems will have plenty more time per day to investigate this problem. And they may have both magnetic fields and how these planets accreted their atmospheres to thank. Email Address. Suggest a Paper Topic! About the Author. About Michael Hammer I am a graduate student at the University of Arizona, where I am working with Kaitlin Kratter on simulating planets, vortices, and other phenomena in protoplanetary disks.
Jim Jeson on April 14, at pm. Leave a Reply Cancel reply. Subscribe Enter your email to receive notifications of new posts. Follow us on Twitter Follow astrobites. Like us on Facebook.
0コメント