The icon indicates free access to linked research in JSTOR.
I got some great questions from the kids once they found out I was an astronomer. Some kids asked me if it was possible to stand on the surface of Jupiter. We know Jupiter has lots of clouds and a thick atmosphere. But if you dive deep enough, and assuming you’re not crushed by atmospheric pressure or planetary gravity, will you find land you can stand on? To answer that question, we first need to peer beneath the clouds to see what the planets look like.
Jupiter’s Ocean
Floating in the giant clouds of the Solar System are oceans.
As you descend into the outer planet’s atmosphere, two things happen: The temperature gets hotter, and the pressure increases. Jupiter and Saturn are gas giants made mostly of hydrogen and helium. At a certain depth, hydrogen, along with perhaps some liquid helium, is compressed into oceans. Jupiter’s ocean may be the largest ocean in the Solar System, and its pressure is so great that hydrogen loses its electrons, turning it into liquid metal. When moving, these oceans create electric currents that give Jupiter a magnetic field 15 times greater than that of the Sun. This is the largest magnetic field of any planet in the Solar System.
Neptune via NASA/JPL
Uranus and Neptune may also have oceans, this time with liquid water. In addition to hydrogen and helium, this ice giant has a high percentage of water and ice. Although this idea is still controversial, some scientists believe that at a certain depth this water becomes liquid, and at a molecular level it may be mixed with minerals. This liquid may be very hot above the boiling point of water, but the high pressure in the cloud above prevents it from boiling.
Stormy Weather, Diamond Rain
For 200 years, we have known about a storm on Jupiter called the Great Red Spot. Earth was able to enter the Spot, and the storm extended about 350 kilometers into the planet. (The highest thunderstorm recorded on Earth was about 20 km high.) At this depth, temperatures are too high for water to condense, which means storms on Jupiter work very differently than storms on Earth.
Meanwhile, the fastest wind in the Solar System belongs to Neptune, with a speed of 2,000 km per hour. This speed can be explained in part by large shifts in the atmosphere, caused by different latitudinal bands rotating at their own speeds. Additionally, Neptune’s cloud tops are cooler than –200°C, but the planet’s interior is a scorching 5,100°C. This temperature difference contributes to strong winds.
Saturn’s Hexagon as the Summer Solstice Approaches via NASA/JPL-Caltech/Space Science Institute/Hampton University
Then there’s Saturn’s strange hexagon, a six-sided band of clouds above the north pole produced by the polar jet stream. Its shape is unique in the Solar System, and may have been formed by different layers rotating at different speeds.
Uranus and Neptune may have some other amazing attributes. For example, there might be oceans and rainstorms of liquid diamonds on Uranus and Neptune. On Earth, scientists discovered that with enough heat and pressure, diamonds can melt without becoming graphite. Although we have not observed liquid diamonds directly on Uranus and Neptune, pressure and temperature have created the right conditions. Diamond showers can also occur on Saturn and Jupiter. There may be other types of strange rain on Saturn. One of the rings rains material back onto the planet, and contains a mixture of carbon dioxide, butane, propane, ammonia and water.
Some Like It Hot
Apart from the strange rain, the interior of the outer planet is also very hot. In fact, Saturn, Jupiter and Neptune emit more heat than they receive from the Sun, in part because, when forming, the planets cooled slowly as they radiated energy back into space. But what’s strange is that although we can explain Jupiter’s interior heat through this mechanism, we can’t do the same for Saturn, another gas giant. Scientists have difficulty explaining why, but there are suggestions that Saturn may have helium showers. The Galileo probe detected helium rain on Jupiter, and if such rain occurred on Saturn, the impact could be amplified by Saturn’s lower internal entropy—that is, friction from raindrops would heat the planet’s core. This idea has some merit, because Saturn’s upper layers have less helium than expected.
Uranus as seen by NASA’s Voyager 2 via NASA/JPL-Caltech
Uranus is the strangest. It does not emit more heat than it receives from the Sun. The planet is much cooler than the other ice giant, Neptune, although Neptune’s orbit is farther from Uranus than Saturn’s orbit is from the Sun. So any processes that heat Jupiter, Saturn, and Neptune are not occurring on Uranus. The reason is a mystery. Some people believe that this may have something to do with events during its formation that made Uranus tilt, while others argue that it has something to do with the structure of the planet’s interior.
So, Can You Stand on Jupiter?
Now, we can finally return to the original question: Can you stand on the surface of Jupiter or one of these giants? Probably not.
Saturn’s clouds move at different speeds depending on latitude. Clouds near the poles move more slowly than clouds at the equator. This differential rotation is visible to a depth of 10,000 km, or one-sixth of the way to the planet. In Saturn’s core, which is about 12 to 20 times the size of Earth, there is a concentration of heavy elements.
Between Saturn’s core and its clouds, we can imagine several scenarios. One consists of layers, and comes with a clear definition between land and atmosphere. Many previous models of Saturn’s interior envisioned distinct layers, but there is another possibility: Saturn’s core became rocky only gradually, as hydrogen and helium slowly mixed with heavier elements in the core. Such models are often referred to as “fuzzy cores”.
Six years ago, the Cassini space probe ended its mission and fell through Saturn’s clouds. When it crashes into a planet, it transmits gravity data that scientists have analyzed to determine the properties of the planet’s interior, and those observations support the fuzzy core model. A similar nucleus is thought to exist on Jupiter, while Uranus and Neptune may or may not have one. It’s hard to know for sure until we have more detailed observations of the planets.
Support JSTOR Every Day! Join our membership program on Patreon today.
2023-10-21 14:14:48
#Stand #Surface #Jupiter #Exploring #Enigmatic #Outer #Planets #SurabayaPostKota.net
