sign in sign up
<<
Home , Extraterrestrial vortex, Rings of Saturn, Tholin

1

The Alien World of Paul Modrowski Chemistry 201

On , diamonds form underground by millions of years of geologic pressure and heat. They are then mined out, polished, and sold for thousands of dollars. They are the most valuable and rare gemstone. However, on Saturn, it rains diamonds. Deep in the 's , and temperatures are so immense carbon are readily crushed into the hardest known material in the universe. On Saturn, matter undergoes many extraordinary physical and chemical changes. The planet is radically different from Earth making it as well as it's raining and , , fascinating to study.

Saturn has been known by man since time antiquity. It is the Sixth and most distant planet easily seen by the naked . elliptical images from 836,600,000 to 940,000,000 miles (1.353 x 10^9 to 1.514 x 10^9 km) from the . Oftentimes, planetary distances are measured in astronomical units for convenience. Saturn is 9 to 10 AU or more plainly spoken 9 to 10 times farther out in the than Earth. , the next closest planet to Earth is about half the distance and almost 5 AU.

For thousands of years, civilizations around the world believed in a geocentric universe. The word planet derives from Latin "planeta" which means wanderer. were just odd wandering stars. It was not until the 1500s that Copernicus figured out planets circle the sun rather than Earth. The Polish was largely ignored until his theory was confirmed by with a self- designed . In 1610, Galileo was the first to notice matter around Saturn. However, he mistakenly thought the blurs were two . To see distinctly, the rings require a telescope with thirty times and were not discovered until Christian in 1659.

The are 71,000 miles in width and have a total span of 225,000 miles, three times the planet’s diameter. However, the rings are less than one mile thick. Due to their thinness, twice every Saturnian year (almost 30 years), they will disappear from view. Contrarily, the best time to observe the rings are during Saturn’s solstice and opposition (opposite the sun). Saturn has an axial 2 tilt of 26.73° and when facing directly towards the sun or away, the rings gain the most reflective . Opposition is important to have Saturn in the darkest night sky.

. . . Saturn Solstices and Oppositions There are 7 main groups of rings around Saturn. Each group at a different speed. A couple outside the main dish orbit in retrograde. The rings are made mostly of with small amounts of impurities and amorphous carbon. Particle matter ranges in size from fine grains of sand to enormous boulders. There are also dozens, possibly hundreds of , objects with 50-500 meter diameters. Some of the material in Saturn’s rings is debris from and collisions. The enormous planets of Jupiter and Saturn swept up a great quantity of loose matter in the early solar system. In fact, the traditional hypothesis is the rings formed several billion years ago and are nebular left overs. The sun had a disk cloud that created planets. Likewise, Saturn has a disk that formed moons. Jupiter and other gas giants have rings, albeit they are much smaller. In 2017, the space probe Cassini ended its mission to study Saturn. Analysis of ring data surprised scientists. There was much more pure water ice than expected. Over a few billion years, orbiting frozen water should have collected a lot of particulate. A fresh snowfall is white and gradually becomes dark and dingy. Why were the rings so pristine? A new hypothesis speculated a moon was torn apart by Saturn’s 10 to 100 million years ago. The moon has been observed stretching from Jupiter’s gravity. If it was nudged a bit closer, it would become a ring of debris.

Destroyed Moon - Ring Hypothesis Saturn was recently crowned the new moon king. It has 82 moons, 53 of which were given names. There are also numerous ‘micromoons’ too small to be classified as moons. Most of Saturn’s satellites are a fraction the size of Earth’s moon. Some are only a few miles across and not at all spherical. looks like a massive rock in the belt. 3

Ninety percent of Saturn’s orbital mass is contained in the giant moon Titan. It is half the size of Earth and larger than the planet . Titan is the second largest moon in the solar system and the only moon to have an atmosphere. The atmosphere is dense and protected by

Saturn’s electromagnetic field. Air around Titan is 94% (N2) and 5.4% (CH4). Titan is also remarkable in that it is the only planetary body in the solar system with lakes and rivers other than Earth. Some of these lakes are larger than N. America’s Great Lakes. Like on Earth, they also appear blue. have occasionally described them as “beautiful”. However, these are lakes of liquid methane and very toxic. They are also fatally cold. The average surface temperature of Titan is a frigid -290°F (-179°C). Because methane becomes a liquid at - 296.4 °F, it is both a liquid and a gas on the moon. Most of the liquid is found at higher latitudes where temperatures are colder. In the relatively warmer equatorial regions, there is large swaths of ice (C2H2(s)). Oddly, liquid and ice exists in zones opposite that on Earth.

Titan’s surface is full of rich organics. Lakes of methane evaporate into clouds leaving behind crystals. Benzene is also believed to be synthesized from acetylene ice (3c2H2(s)

→ C6H6(s)). Precipitation on Titan is both a liquid and solid. Clouds of methane will convert back to liquid as rain. Higher in the atmosphere, solar radiation causes . Molecules of methane are broke down into CH, CH2, and CH3 radicals. These radicals combine to form liquid methane and (C2H6(l)) as well as solids acetylene (C2H2(s)), propane (C3H8(s)), benzene

(C6H6(s)) and other heavy . Much of Titan’s midsection is ice and dunes of dark organic particulate. Saturn is the second largest planet in the solar system. It is called a because it is composed primarily of and helium. These gases spin so quickly that Saturn is oblate spheroid. The diameter at the equator is 10% greater than the distance from pole to pole. Saturn has a volume of 8.2713 x 1014 km3 and over 760 could fit within it. However, due to its composition of light elements, the density is much less than Earth. Earth has a mean density of 4

5.51 g/cm3 and Saturn only .69 g/cm3. It is said Saturn could float on water, yet in such an imaginative hypothetical, the planet’s layers of gas and liquids would be shed and the core would sink. Saturn has a pale yellow-orange hue which is the result of trace amounts of and ethane in its outer atmosphere. Results of estimate a composition of 96.3% hydrogen

(H2), 3.25% helium (He), .45% methane (CH4), .01% ammonia (NH3) and .01% (HD). From a telescope, Saturn looks rather bland and lacks much contrast other than faint bands. However, periodically, enormous white storm clouds will appear. Such a phenomena is expected to occur in 2020 during the N. hemisphere’s summer solstice. Voyager and Cassini spacecraft have also discovered bizarre weather patterns on the poles. A hexagonal wave pattern rotates on top and a the size of Earth on bottom. This enormous hurricane-like storm has winds of 340 mph, a thousand times the strength on our plant, and is speculated to have been raging for over a billion years. Cloud formation varies with temperature and pressure on Saturn. From 1 and 2 bars (Apx. 1 to 2 times the pressure on Earth at sea level) and between -300°F to -170°F, clouds are composed of ammonia ice crystals. Below this layer are clouds of water ice and hydrosulfide ice

(NH4SH(S)). Almost 20 bars of pressure are required to create clouds of water vapor (H2O(g)) and ammonia in aqueous solution. Like on Titan, methane is photodissociated by solar emissions to produce CH, CH2, and CH3 radicals. Subsequent chemical reactions between the photolysis products create several heavy hydrocarbons which diffuse down through bars of atmospheric pressure. They eventually encounter high temperatures and are thermochemically converted back to CH4, completing a methane cycle. Temperatures at the base of cloud levels are at 130°F. It is unknown if Saturn has a real surface. Most planetary models, however, predict there is a core made up of iron-nickel and rock (silicon and compounds). The core should be similar in composition to Earth’s but much denser and larger. Estimates are Saturn’s core is nine to twenty-two times the mass of Earth and Apx. 15,500 miles in diameter are 1/5th Saturn’s equatorial diameter. The interior of Saturn exceeds 21,000°F and radiates 2 ½ times more energy out into space than it receives from the sun. Enormous gravitational compression creates most of this heat. However, friction from helium droplets descending through lower density hydrogen most likely contributes. 5

The core is surrounded by a layer of thick liquid metallic hydrogen. It is within this molten hydrogen that electric current flows creating Saturn’s electromagnetic field. The electromagnetic field is weaker than Earth’s, but projects farther outward and efficiently protects Saturn from destructive solar . It also protects Titan’s atmosphere from being torn off. On top of the layer of liquid metallic hydrogen is a layer of liquid helium-saturated molecular hydrogen. Going further outward these elements gradually transition to gases. There is also a transition of the ratio of H2 and He. Around the compressed gas-liquids, the ratio is roughly even. With altitude, there is increasing proportions of hydrogen. Hydrogen is the lighter element. Helium sings more readily downward and bleeds into its liquid counterpart. It rains both helium droplets and diamonds. Much remains enigmatic about Saturn and its moon Titan. NASA has plans to send yet another space probe to study the strange worlds in 2026. This craft will have a flying robot aboard to land on Titan and search for alien or its molecular precursors. The quadcopter named “” is being designed so it may travel to numerous locations and analyze organic molecules. Dragonfly will not reach the moon until 2034, but, maybe then will have more answers or just more questions. The quest to understand the universe is never ending.