The Eye Of The Storm
As you might have gathered by now, most articles posted here revolved around planets or objects located in our Solar System, and today is no exception. The planet in question is named after the chief Roman deity, and rightfully so. That’s right, we’re talking about Jupiter. It is not possible to determine when Jupiter was first discovered, but we do know that is was mentioned in scripts written by ancient astronomers, and was associated with religious believes and mythology of many cultures, not just the Romans. The oldest record of Jupiter was in Babylonian texts, dating as far as seven or eight centuries BC.
After reading this, you might think that Jupiter has some pretty big shoes to fill, and it does so succesfully. For starters, it is the largest planet in the Solar System. Let’s do the numbers, so you can get a better idea of how truly massive it actually is. The mean diameter of Jupiter is 138,346,005 kilometers, while the equatorial and the polar diameters are 142,984 and 133,709 kilometers, respectively. This is due to the fact that Jupiter has the fastest rotation of all planets, so fast that the days are only 10 hours long. Such fast rotation causes the flattening of the planet, making it bulge out at its equator. It is also responsible for generating Jupiter’s powerful magnetic field, and contributes to the dangerous radiation surrounding it, which is so strong that it can even be measured on Earth.
Jupiter and Saturn are commonly referred to as “twins”, for several reasons. Both planets are gas giants, close to similar in terms of size, but also for the fact that Jupiter has rings as well, although compared to Saturn’s, they are much fainter, and are mostly made up of debris ejected by its moons when struck by meteorites. Just as Saturn has rings as its defining feature, Jupiter has the Great Red Spot. The Great Red Spot is actually a storm that has been raging on since the 17th century, when it was first observed by astonomers, and it’s possible it could be even older. It measured 40,000 kilometers across one century ago, and even though it has shrunk to half its size in the meantime, astronomers still have no idea when or if it will disappear completely.
Three-color filter image of Jupiter’s best known feature, the Great Red Spot. (Voyager 1)
Compared to Earth’s, Jupiter’s magnetic field is 14 times stronger. We’ve already mentioned that one of the reasons is its fast rotation, but scientists also think this is caused by the movement of metallic hydrogen that can be found deep inside Jupiter. The powerful magnetic field attracts ionized particles brought to Jupiter’s orbit by the solar winds, and accelerates them to almost the speed of light, causing damage to any spacecraft that might come close.
Despite that, 7 spacecrafts launched from Earth managed to visit Jupiter, first of which was Pioneer 10, launched in December 1972, by NASA. It was followed by Pioneer 11 in December 1974. After that, it was visited by Voyager 1 and 2 in 1979. It wasn’t until 1992, and the launch of Ulysses in 1992 that another spacecraft visited Jupiter. This continued with Cassini making a flyby in 2000, while on it’s way to Saturn. Latest one to visit Jupiter on its flyby, and hopefully not the last one, was the New Horizons spacecraft, launched by NASA in 2007.