What's a planet?
"A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit."
This is the definition provided by NASA. Well in the past it was thought that all the planet's crust was rigid. Well the famous astronomer Giovanni Cassini.
He found out that the rotation rates of the planet was dependent of the latitude. This is because of the centrifugal force. The same reason why the radius of Earth is different at the equator and the pole and the acceleration due to gravity is less at poles compared to equater. This would not have been possible if the planet crust was rigid as Earths or moon. So, he concluded that the planet was made up on fluid. But the term gas giant was coined in 1952 by a science fiction writer James Blish.
Now lets go a bit deeper into Jupiter:
Jupiter is the largest planet in our solar system. It has a radius almost 11 times the size of Earth. It has 53 known moons and 26 waiting to be confirmed, according to NASA and the largest moon(Ganymede) is bigger than mercury and Pluto. The planet is mostly made of hydrogen and helium surrounding a dense core of rocks and ice, with most of its bulk likely made up of liquid metallic hydrogen, which creates a huge magnetic field. Jupiter is visible with the naked eye and was known by the ancients. Its atmosphere consists mostly of hydrogen, helium, ammonia and methane.
Look at the image here this is a infrared image of the Jupiter. If we compare the view of Jupiter in the infrared to the visible, we see that the belts are warmer than the zones. Scientists that heat from the interior of the planet warms gas, which rises up in the belts, cools off, then falls back down through the zones to the interior again.
Scientists are still trying to understand the "weather" on Jupiter. On Earth, the energy which drives winds and fronts comes from the outside -- from the Sun. But on Jupiter, it appears that the dominant force of energy input to the atmosphere comes from the inside -- from residual heat left over from the planet's formation, four and a half billion years ago, which is slowly leaking outwards.
The gas in adjacent zones and belts moves at slightly different speeds, causing all sorts of interesting eddies and vortices at their interfaces.
The largest of these is a gigantic cyclonic storm called The Great Red Spot, which has been visible in the planet's atmosphere for over three hundred years.
Current Research on Jupiter:
NASA's Juno spacecraft arrived at the planet in 2016 and has already made several discoveries. It studied the planet's rings, which is difficult to achieve since they are far subtler than Saturn's. Juno discovered that the particles influencing the auroras of Jupiter are different than those on Earth. It also revealed insights about the atmosphere, such as finding snow emanating from high-altitude clouds. Meanwhile, scientists using the Hubble Space Telescope have made detailed studies of Jupiter's Great Red Spot, watching it shrink and intensify in color.
In a future post we will dive deeper into gas giants. Signup to have discussion. and Signup to our news letter to get the posts right into your inbox.
Thanks for your Time.
Commentaires