The Two Largest Planets of our Solar System
A great storm, on one of the planets of our solar system, so powerful and huge, which can easily swallow something as big as Earth, that too 2–3 times, is going on for the last 400 years and will go on for a period that can’t be determined.
It was the night of January the seventh, 1610. One of the most famous astronomers in Italy was looking at the sky. Suddenly, his gaze fell on three shiny objects in front of a big planet. He initially thought that these were 3 stars. The very next night, these objects were found heading towards the other direction. After studying these objects for a week, one more such object was found near Jupiter. After studying these objects for several weeks, the astronomer deduced that these objects were always found near Jupiter. The astronomer thus deduced that these were not stars but the moons of Jupiter. That astronomer was none other than Galileo Galilei.
Those four were the biggest moons of Jupiter, namely Io, Europa, Ganymede, and Callisto. At the time of writing this blog, 79 moons of Jupiter have been discovered. The planet is about 780,000,000 km away from the Sun. Jupiter is so big that about 1300 Earths can completely fit in it. Jupiter is about 300 times heavier than the Earth. However, its density is only about one-fourth of that of the Earth. Its shape is different in different places. At its equator, its diameter is about 143,000 km. This gets reduced to 135,000 km at the poles. Despite being so big, the rotation period about its axis is only about 10 hours. That is the fastest in the whole of the solar system. The planet gets its banded appearance due to the long seasons that originate due to the fast rotation of the planet. The planet is composed of about 90% Hydrogen and small amounts of Helium, Methane, Ammonia, Sulphur, and water. The core of the planet is about twice as big as the Earth, and it has a temperature ranging up to 30,000 °C, that’s 24000 °C more than the Sun! This has led to the formation of the great red spot(the storm which was talked about earlier).
On September the fifth, 1977 Nasa sent Voyager-1towards Jupiter. It reached the planet during March of 1979. The images sent by satellite revealed the presence of rings around the planet. These rings comprise of dust and small rocks, as a result of which they reflect only a small part of the light they receive. These rings can be further categorised into Halo, Main and Gossamer ring. Talking about rings, another planet which catches our attention is Saturn.
In 1610, Galileo became the first person ever to see the rings of Saturn. The rings are made up of ice and pieces of rocks, which gives it its shiny appearance. Earlier he had thought that Saturn was a group of three planets. Two years later when the planet had changed its position in the orbit, and the rings had become invisible, Galileo gave the theory that the central planet had swallowed up the adjoining ones. In 1895, famous scientist James Keeler proved that different parts of the rings move with different speeds. Even though thousands of rings surround Saturn, but on a whole, these rings have been categorised into 5 major parts, namely D, C, B, A and F. There are 2 more rings, G and E, but these are barely visible. The rings A, B and C can be seen from Earth.
Saturn is about 1,430,000,000 km away from the Sun. Its diameter is about 120,500 km. It is about 10 times as big as the Earth. After Jupiter, it is the second-largest planet of the solar system. About 700 Earths can fit inside it. It is 95 times heavier than the Earth. The strange thing about this planet is that it has the least density among all the planets. Its density is even less than water, that is it can float on water(provided enough water and a place for it to float is given!). Its composition is very much similar to that of Jupiter. Saturn doesn’t get huge storms like the red spot, but it can get dangerous storms too. In 1990, a storm as big as 2 Earths combined was seen on the planet. It was named the White Storm. Such kind of storms is usually referred to as The Great White Spot. These are periodic with a period of about 30 years. This is the same time which the planet takes to revolve once around the Sun. They last for about 3 weeks. The next great white spot will occur in 2020(don’t forget to have a look at it!). Inspired by the discovery of Jupiter’s moons by Galilei, a dutch astronomer took the responsibility to improve the then present telescopes and find something else in the universe.
On the twenty-fifth of March, 1655 he discovered Saturn’s largest moon: Titan. That astronomer was none other than Christiaan Huygens. Titan, after Jupiter’s Ganymede, is the second-largest moon of the solar system. The speciality of Titan is its Earth-like atmosphere. Despite this, life is not possible on the moon because its average temperature is about -170 °C. Rivers flowing with methane can also be found on the moon. Between the years 1673 and 1686, Italian-French astronomer Jean-Dominique Cassinihad discovered 4 more moons of Saturn. These were Iapetus, Rhea, Tethys and Dione. The most unique among them is the one with a diameter of 1500 km. The moon I am talking about is Iapetus. One half of its body reflects as much as 50% of the light incident on its body while the other half can reflect a mere 3%. The complete opposite happens on one the other moons, namely Enceladus. It reflects as much as 90% of the light incident on it. As compared to them Earth reflects only 39% light incident on it while our moon can reflect only a meagre 7 %!
In October 1997, NASA and ESA launched Cassini-Huygens joint aircraft, which reached Titan during January 2005. Till date, the satellite is providing us with essential information about the planet.
These planets, though quite far, have been constantly increasing the curiosity of the inhabitants of Earth since the early seventeenth century, and no one knows what more is in store for us to learn from these two giant balls of gases.
