Jupiter and its super moons
Jupiter is the biggest planet in our solar system. There are so many mysteries surrounding this planet. Jupiter has four big moons and many smaller moons. The super moons of Jupiter are promising in terms of liquid water which makes them interesting to mankind. So let us learn more about Jupiter and its moons.
About Jupiter Jupiter is 778.5 million km away from the Sun. Yet it is the fourth most brightest object in the night sky. Jupiter is a gas giant, made mostly of hydrogen and helium gases just like the Sun. It occupies the position of the fifth planet in the solar system and is incredibly huge. For all these reasons it was aptly named after Jupiter, the Roman king of gods. It is astonishing how almost all the cultures around the world gave Jupiter a kingly and scholarly status. The planet is often associated with thunder. Thor, the Nordic god of thunder was associated with Jupiter. Zeus, the Greek king of gods, the wielder of thunder was also associated with Jupiter. Assyrian chief, thunder God Marduk was also associated with Jupiter. Coincidentally Jupiter is ridden with storms which last for centuries.
Let us learn more about this mysterious planet.
- Size: How huge is Jupiter? All the planets in solar system can literally fit into Jupiter. It has a massive radius of 69,911km and its mass is 1.89*10^27 kg. A planet that size reflects a huge amount of light it gets from Sun makes it visible to a naked eye from here on Earth.
- Atmosphere :The atmosphere of Jupiter mostly comprise of Hydrogen. It also has ammonia, methane and water in little amounts. The clouds of Jupiter are divided into belts and zones. The belts are composed of ammonia and sulfur making them look reddish in comparison with zones. Jupiter is infested with cyclones. One certain cyclone called 'The Great Red Spot' has raged for 350 years. The cyclone is so huge that three Earths can fit into it. The cyclone had been spinning this long with a 600 km/h speed.
- Rotation and Revolution : Jupiter has the shortest day in all the planets, which lasts for 9 hours and 53 minutes. That must tell how fast Jupiter rotates. It rotates at a 43,000 km/h speed. Jupiter revolves around Sun in 11.8 Earth years. Such enormous speeds make the planet bulge at its equator.
- Rings: Jupiter has four faint rings. Since Jupiter is so huge with a gravity of 24.9 m/s^2, it pulls stray comets and asteroids to itself. Because of the debris caused by impacts, rings are formed around Jupiter, 225,000 km from the planet.
- Temperature and pressure : The atmospheric temperature is -146 degree Celsius. But due to the friction of these gaseous clouds and intense pressure create upto 10,000 degree Celsius temperature at the surface. An atmospheric pressure of 100kPa is always being exerted.
We have learnt how Jupiter is both massive and amusing through its description. But there is also a debate regarding the birth of Jupiter. Because most of the atmosphere of this gaseous giant is hydrogen, it is believed that gases from nebulae gathered and formed as Jupiter. Jupiter does have many attributes as stars. But its mass is just 1/1000th of the Sun, limiting it to a planet. Jupiter also reflects more heat than it receives from the Sun. This excess heat is due to the friction of clouds and interacting gravity. Because of its mass, Jupiter is very vulnerable to meteor and comet crashes. Many comets in the direction of Earth, gets deflected by Jupiter. Without Jupiter, Earth would see far more meteor attacks. So Jupiter is acting as a secret guardian to the denizens of Earth.
Supermoons of JupiterGalileo in 17th century spotted four moons of Jupiter. They were named Ganymede, Io, Callisto and Europa later. All of these moons are tidally locked with Jupiter which means they always show only one face to Jupiter. This also means the time of rotation and revolution are also almost same.
- Ganymede: The largest of Jupiter's supermoons, with a diameter of 5,262 km. It is larger than Mercury. Ganymede was a Greek prince who was abducted by Zeus/Jupiter. It is made of rock and ice
Some interesting features of Ganymede are:
- Ganymede is the only moon in solar system to have a strong magnetic field.
- It has a iron nickel core and is said to possess sub-surface liquid water.
- Ganymede has a thin atmosphere that contains oxygen.
- Callisto : Callisto is another super moon of Jupiter, named after a nymph who attracted Jupiter/Zeus. It has a diameter of 4,820 km. It is the second largest moon of Jupiter
Features of Callisto:
- It is the most heavily cratered object in the solar system. The surface is mostly rock and ice with traces of underground water. The waters beneath the surface must be filled with ammonia and salts.
- The surface of Callisto has silica and hydrocarbons. Hydrocarbon presence indicates that carbon-based life might exist in Callisto.
- The atmosphere of Callisto is carbon dioxide rich, and being a green house gas, carbon dioxide traps the heat absorbed by the moon. Thus Callisto having liquid water, sufficient heat and hydrocarbon compounds seems to be the most promising place to house an alien life inside the solar system.
- Io : Could possibly have the most busiest surface in the whole solar system. It has over 3600 km diameter and this small moon has nearly 400 active volcanoes on its surface. Io was a priestess of Juno/Hera, Zeus's wife. Zeus once again couldn't control his lust and advanced on Io. Instead of helping her, Juno turned her into a white heifer. The moon Io is very close to Jupiter thus earning its name.
Features of Io:
- Io has too many volcanoes because of its closeness to massive Jupiter. The tidal forces cause the inner magma of Io to burst forth as volcanoes.
- Because of all that volcanic activity sulphur dioxide makes a huge part of Io's thin atmosphere.
- It is very mountainous with some peaks as high as 6 km.
- Io experiences a huge amount of radiation from Jupiter and its atmosphere is very toxic.
- Europa : It is the smallest super moon of Jupiter. It spans across a 3000 km diameter. It was named after a princess who was abducted by Jupiter in the form of a bull. The continent Europe is named after her. And so is this moon of Jupiter
Features of Europa:
- Europa is said to house a vast amount of water underneath its crust
- It also,like Ganymede, has a magnetic field. Which means it has an iron core like Earth. Having a magnetic field is absolutely necessary to support life.
It is common in astronomical nomenclature to name planets and stars after Roman gods, moons after their consorts and craters after artists. From the study of Jupiter and its super moons we get to understand that Europa is the most suitable place other than Earth where life can prosper. Callisto and Ganymede too promising liquid water and little oxygen are reliable habitable spaces. Another funny observation can be made that Jupiter's super moons are all named after people Jupiter/Zeus abducted, when his actual consort Juno is does not share her name with any other moon of Jupiter. Instead the space probe Juno was named after her which would revolve Jupiter study it and finally crash into it. The biggest planet is still shrouded in many mysteries. We keep finding newer moons. This was a little part of the never ending mystery.