StarTalk - George's Anus

I love talking about astronomy. It is fascinating and raps up science, history, mythology, mathematics and culture into one brilliant container. StarTalk is a podcast by Dr Neil deGrasse Tyson and some other hosts. 

The episode I came across today that tickled my fancy is about how the planets and moons in our solar system got their names, the exceptions to the rule, and the reasons why. The episode was with Mr Chuck Nice, a comedian who asked questions that we non-professional astronomists would love to ask and would make it funny and understandable to the common man in the street.

The International Astronomical Union (IAU) has been the body responsible for naming astronomical bodies since its inception in 1919. They followed a rule when it came to naming the planets. Since these have been known to us since antiquity, they use their Latin names as done in other fields like Medicine, Chemistry,  etc. The Romans knew of seven bright objects in the sky: the Sun, the Moon, and the five brightest planets. They named them after their most important gods. The planets from Mercury to Saturn are all visible to the naked eye and were named by the Greeks and, subsequently, the Romans; hence, we kept their Roman names, with the rich mythology that goes with them. 

Mercury was named so because it was fast, the nearest planet to the Sun and the smallest planet in our Solar System. Mercury goes so fast that it takes only 88 days to rotate around the Sun. Pictures showed a planet without an atmosphere with numerous craters on its surface. In Roman mythology, Mercury is the messenger of the gods. The Greek name is Hermes. Venus is very shiny because highly reflective clouds blanket it. The clouds in the atmosphere of Venus contain droplets of sulfuric acid, as well as acidic crystals suspended in a mixture of gases. Light bounces quickly off the smooth surfaces of these spheres and crystals. The next planet is Venus, although farther from the Sun by more than 50 million kilometres than Mercury, its surface temperature is far hotter due to global warming. Although a beauty in the sky living on Venus could kill you in seconds. The Soviets set four probes to this hellish planet from 1971 to 1985 and sent back pictures. These pictures depicted a hellish, rocky environment. Venus is the Roman goddess of love, and its Greek equivalent, i.e. goddess of love, is Aphrodite. Mars is orange-reddish because its soil has iron oxide or rust particles. The planet was named Mars, the Roman god of War, because of its red colour, similar to blood. Mars's surface is red and rocky, but we understand Mars better from the numerous probes sent there. Mars once had liquid water running on its surface and a big sea. There is still water underground and the polar regions in the form of ice. There might be microbe life on Mars. Its Greek equivalent name for the god of War is Ares. The four innermost planets, Mercury, Venus, Earth and Mars, are known as Rocky (Terrestrial) planets. The outer group of planets Jupiter, Saturn, Uranus and Neptune are far bigger and are composed of mainly gases, Hydrogen and Helium. These outer planets are known as the Gas giants. Between the inner and outer planets, i.e. Mars and Jupiter, are numerous rocks, asteroids and "minor planets" floating in a group known as the Asteroid belt. Then, because of its immense size, Jupiter was named after the King of the gods. It is the biggest planet in our Solar System. It has a diameter of 88,695 miles (142,800 kilometres), more than 11 times the diameter of Earth. Its volume is over 1,300 times the volume of Earth. One thing about Jupiter is it is significant; apart from its enormous size, it has mighty radio waves disseminating from it. The waves can destroy any unprotected probes going around or near it. Also, it has a big red spot, which is said to be a storm of massive proportions. This storm has been there since it was noticed and has been going on for more than 300 years. The Greek equivalent of Jupiter is Zeus. The next planet is named Saturn, after the Roman god of Agriculture. Saturn is the one with visible rings around the middle. The Greek equivalent is Cronus. The next planet and the other planets' various moons were discovered in the telescope's introduction.

Uranus had been observed on many occasions before its recognition as a planet, but it was generally mistaken for a star. Sir William Herschel observed Uranus on March 13 1781, from the garden of his house at 19 New King Street in Bath, Somerset, England. He presented his findings to the Royal Society and named it Georgium Sidus (George's Star), or the "Georgian Planet", in honour of his patron, King George III. Uranus is tilted on its side, and this unique tilt makes Uranus appear to spin on its side. It takes 84 years to make one rotation around the Sun. The comedian said it would have been known as Georgie's Anus. But the powers that be decided on Uranus, which references the ancient Greek deity of the sky. As a "constellation (consolation) prize" to the English, all the moons of Uranus were named after all characters in plays by the famous English author William Shakespeare. 

Io, Callisto, Europa and Ganymede are known as the Galilean moons because the first recorded observation of the moons was by Italian astronomer Galileo Galilei in 1610 when observing Jupiter. He was the first to identify them (or record that he had identified them). The movement of these moons around Jupiter and the observation of Jupiter around the Sun was responsible for Galileo's conviction of the Heliocentric universe, according to Nicolaus Copernicus, a Polish priest that he published in his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), just before his death in 1543. Galileo also published a book titled ""dialogue Concerning the Two Chief World Systems""(1632). The moons of Jupiter are all Greek characters associated with Jupiter (Zeus). Io was regarded as the first priestess of Hera, the wife of Zeus. Zeus fell in love with her and, to protect her from the wrath of Hera, changed her into a white heifer. Callisto was a nymph and a follower of Artemis. Zeus developed an attraction to Callisto and turned himself into Artemis to lure Callisto. Zeus sees the young Europa and falls in love with her beauty, so he seduces her. So that the young princess would not be frightened by his divine presence, Zeus takes the form of a bull and mixes in with Europa's herd. Ganymede was an exceedingly handsome, aristocratic young Trojan abducted by Zeus to become his cupbearer. Their moons also have interesting stories. Io is the most volcanically active world in the Solar System, with hundreds of volcanoes, some erupting lava fountains due to the pressures from Jupiter. Jupiter's second-largest moon, Callisto and the third-largest moon in our solar system. Its surface is the most heavily cratered of any object in our solar system. Europa has another exciting story. It is the smoothest known object in the Solar System, lacking large-scale features such as mountains and craters. The apparent youth and smoothness of the surface have led to the hypothesis that a water ocean exists beneath the surface, which could conceivably harbour extraterrestrial life. It has been seen to eject plumes of liquid water into space. Then, there is Ganymede, the largest moon in the solar system. This icy world is the only moon with its magnetic field – and the atmospheric auroras that come with it. Then there are up to 60 more, making up to 64 moons of Jupiter, and they keep finding more. Mars has Phobos and Deimos, always present the same face on their planet. Both are lumpy, heavily cratered and covered in dust and lose rocks, some believed to be captured asteroids. In mythology, both were sons of Ares and Aphrodite. Phobos is the god and personification of fear and panic in Greek mythology. Deimos is the personal god of dread and terror. Venus and Mercury have no moons since they are near the Sun. It is believed that they might have lost their moons due to the Sun's gravitational pull. Saturn has the second largest moon in our solar system, named Titan. Titan, although very cold, has rivers and oceans of liquid water. The water is believed to be in liquid form because it has a layer of salty liquid water, a dense atmosphere of clouds, and oceans of liquid hydrogen and methane with a complex weather system. The pieces of these molecules recombine to form a variety of organic chemicals (substances that contain carbon and hydrogen), often including nitrogen, oxygen and other elements essential to life on Earth. It is believed that if Titan has life, it will not be as we understand it or, in Starterk speak, "not as we know it". The names of the other moons are Dione, Enceladus, Epimetheus, Prometheus, Mimas, Rhea, Janus, Tethys, etc. The then-known seven satellites were named after Titans, Titanesses and Giants—brothers and sisters of Cronus.

The planet Uranus has a Greek name; the Roman equivalent is Caelus. Uranus's five largest moons are Miranda, Ariel, Umbriel, Titania, Oberon, etc. They are not named after mythological characters but characters in Shakespeare's plays. Miranda is from The Tempest, the daughter of Prospero. Also, Ariel is not a human on the magical Island; he is a spirit and a native of the Island on which the drama is set. A more tangibly malicious figure than Ariel is Umbriel. From the "A Midsummer Night's Dream". Titania is the queen of the fairies, and Oberon is King of the Fairies and is married to Titania.

The story of Nepture is that of scientific discovery as they noticed some abnormality in the orbit of Uranus, and it was postulated to be due to the presence of another planet, which would be in the position that Neptune was discovered. By 1845, Uranus had completed nearly one full revolution around the Sun and astronomers Urbain Jean-Joseph Le Verrier in Paris and John Couch Adams in Cambridge, England, independently calculated the location of this postulated planet. Neptune, the Roman god of waters and seas, controlled winds and storms. Its Greek name is Poseidon. Neptune's atmosphere is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen. Still, it contains more ice, such as water, ammonia and methane, giving it a bluish colour. The moons are named Naiad, Thalassa, Despina, Galatea, Larissa, Hippocamp, Proteus, Triton, Nereid, Halimede, Sao, Laomedeia, Psamathe, Neso, etc. Naiad is a nymph in Greek mythology. Thalassa, Greek goddess of the sea. Despina was a demigod, the daughter of Poseidon.

Another aspect I should mention was the search for Vulcan, a theorized planet that some pre-20th century astronomers thought existed in an orbit between Mercury and the Sun. Speculation about inter mercurial bodies or planets and even purported observations dates back to the beginning of the 17th century, after the discovery of Neptune due to aberrations in the orbit of Uranus. Aberrations in the orbit of Mercury were thought to be due to the presence of another planet. In 1915, Einstein's theory of relativity, an approach to understanding gravity entirely differently from classical mechanics, removed the need for Le Verrier's planet. It showed that the peculiarities in Mercury's orbit were the results of the curvature of spacetime caused by the mass of the Sun and not by a new planet. At least I forget in mythology, Vulcan was the Roman god of fire, the forge, and the mythical inventor of smithing and metalworking. His Greek equivalent is Hephaestus.

Pluto was named after the Greek god of the Underworld, and its moons have the names Charon, Styx, Nix, Kerberos, and Hydra. Pluto has been demoted from a planet to a dwarf planet because it was found that there were much bigger bodies in the Kuiper belt. The Kuiper belt is much like the Asteroid belt, but most objects there are frozen methane, ammonia, and water instead of rocks. So, the IAU was forced to state criteria that make up for a planet, and it came up with three.

1. It is in orbit around the Sun.
2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
3. It has "cleared the neighbourhood" around its orbit.

Also in the Kuiper belt is another dwarf planet. Makemake is of the Rapa Nui mythology of Easter Island, is the creator of humanity, the god of fertility and the chief god of the "Tangata manu" or bird-man.

Much more was known about the solar system due to the Voyagers 1 and 2. It was noticed that The Voyager 1 and 2 probes delivered the first detailed views of the solar system's four giant planets and their large, shockingly diverse moons. Voyager 2 lifted off from Cape Canaveral, Florida, on August 20, 1977, with Voyager 1 following 16 days later. The Voyager probes launched to study the planets, but they discovered the wonder of the solar system's moons. Jupiter's turbulent atmosphere, Saturn's morphing rings, the tilted axis of Uranus, and Neptune's Great Dark Spot, among other things. The concept of the Grand Tour began in 1964 when scientists noted that an alignment of Jupiter, Saturn, Uranus, and Neptune that would occur in the late 1970s would enable a single spacecraft to visit all outer planets using gravity assists. The particular alignment occurs once every 175 years. Gravity Assist is the process by which a spacecraft would use the rotation of a planet to gain speed and momentum, saving time and spending less fuel.

Since other nations are going to space, Indian, Chinese, and Hawaiian names are now used to name bodies in our solar system. An example is Makemake, a dwarf planet in the Kuiper belt. Hence, you see how astronomy could be fascinating and very interesting. This only touches the surface of the things known in our Solar System. But I hope this will stimulate your interest.