The Universe

Jupiter was not named after Zeus, the god of all legendary Greek gods, for nothing. He is considered king when it comes to size among all the planets in the Solar System. It is an enormously huge and compact ball of cloud made up of mostly hydrogen and helium. It is incredibly massive that the Earth is almost just as big as the Great Red Spot (a great storm and a remarkable area that can be seen on the planet). Side by side, Jupiter can be compared to a basketball while the Earth can be just as small as a dime. Moreover, if all the other planets will be mashed up into one ball, Jupiter will still be two and a half times bigger.

That nearly answers the question of who discovered Jupiter. Although it is very far from the Earth with a distance of around 470 million miles and is one of the outer planets, it is still so massive that it is the third brightest object in the Earth’s sky. With the Moon as the brightest and Venus as second, Jupiter can be seen by the naked eye and its basic color and moons can even be seen by plainly using binoculars. Sometimes, it can be seen both in early morning and during dawn. It can often be seen a little after sunrise and before or after sunset.

Nobody knows who first saw Jupiter. Along with Venus, the Moon and Mars, it shines bright in the sky and can be seen by the naked eye like a stationary star. The planet was not discovered, but its moons were. Using a telescope, Galileo Galilei discovered four moons which were called Io, Ganymede, Callisto and Europa in 1610. They are often called Galilean moons. Jupiter has sixty-three known moons which makes it the Sun’s counterpart in its own mini solar system. And more unknown moons may still be added to the list.

The moons of Jupiter may even be seen by an ordinary sky gazer if he will use a telescope. If the telescope will be held steady at Jupiter, the seeker should remain focused for one to two minutes or until the eyes get adjusted to the light. If a tiny spot of light just beside Jupiter starts to change color, the sky gazer just sighted one of the Jupiterian moons.

Although named by Romans, it is said that the Babylonians were the first to record their observation of the planet that is now called Jupiter. It is included in the Scribe’s planetary theories about how the setting and rising of heavenly bodies can become omens to humans’ daily living. They have taken
specific notes on when Jupiter rises and appears on the sky and associated it with zodiac-like meanings.

Mars have two satellites, Phobos and Deimos. These moons are irregularly shaped and much smaller than the Earth’s Moon. They were possibly not captured in the same way the Earth’s Moon was. They are thought to be asteroids or rubbles from a collision, which were eventually captured by Mar’s gravitational draw.Since they are too small to cover the sun, a total eclipse never happens in Mars. Odd enough, lunar eclipses occur almost every night.

Phobos, the larger one between the two moons, is egg-shaped and has the dimensions 27×21x19 km. It was named after one of the sons of Ares and Aphrodite. The word ‘phobos’ means fear in Greek and is the root word for ‘phobia’. The satellite phobos is 3000 miles away from Mars and orbits in7.3 hours which means it makes more than 3 orbits in a Martian day. It rises in the west and sets in the east. Phobos is completely invisible from Mars poles. Both Phobos and Deimos have a great deal of craters. It is one reason why they are speculated to be asteroids before they became satellites. Phobos also has parallel grooves, which are 150m long, 25m deep and start from the largest crater and ends on the other side of it. In a few million years, Phobos is believed to cease in existence after a few million years.

Every century, it moves 2 meters closer to Mars surface and eventually may crash into Mars or forma ring of dust around the planet. Deimos is the smaller and outer moon of Mars with the dimensions of 15 × 12.2× 10.4 km and distance of around 23,460 km from Mars. From the surface of Mars, Deimos appears more like a bright spot or star. Although heavily cratered like Phobos, Deimos has tremendous amount of dust covering its surface, which fills and covers up its irregularities. Phobos, on the other hand, is clearer of dust since its distance to Mars could have caused fragments to be pulled off from its surface by Mars’ gravity. Unlike Phobos, it rises from the east and sets in the west. It finishes its orbit in about 30 hours but takes 2.7 martian days since it falls behind Mars’ rotation.

The meaning of the word ‘deimos’ is similar to that of ‘phobos’. It means terror or panic. Deimos, in Greek mythology is the twin brother of Phobos. Both Phobos and Deimos are tidally locked, which means one side of each faces Mars all the time as they orbit around the planet. They were discovered in 1877 by Asaph Hall, an American astronomer. Before the discovery, Johannes Kepler,the German astronomer who is best known for designing the laws of planetary motion, predicted that Mars has two moons. He was correct although his basis was incorrect. He reasoned that since Jupiter has four moons and Earth has two, it follows that Mars have two. Asaph hall, who deliberately searched for the moons found Deimos on August 12, 1877. 6 days after, he sighted Phobos on August 18. He was the one to give the satellites their names.

No other planet has mystified humans more than Mars. Earthlings have not set foot on it yet but stories about it have been told, published, and even inspired movies. It was named after the Roman god of war ‘Ares’, probably years after it was first sighted by a human eye. Who did and when it happened are questions that will not get any answer since it was seen before recorded history. It was first seen during ancient times and the person who should receive credit is unknown. It is Earth’s next-door neighbor, so it can be seen in a cloudless sky even without the use of a telescope. Prehistoric people may have regarded it as an omen or a god that affects their crops harvest or the coming of rain. They saw it but have not really considered that it is almost similar to the planet they were standing on, but just million miles away. They did not know how it will tickle the modern human fancy later on.

The Babylonians of Egypt could have first sighted the planet. Possibly because of its fierce red color, mainly caused by the abundance of iron oxide on its surface, it was called ‘Nergal’ which means ‘The Star of Death’. Mars was also associated to the Babylonian deity Marduk, who was a great ancient warrior. The Egyptians have called it different names, including ‘Her Deschel’ which means ‘The Red One’.

During modern times, Mars position was amazingly assumed by calculations made by Tycho Brahe. He is a Danish astronomer and alchemist known for his precise and elaborate astronomical observations. In 1576, he accurately calculated the position of Mars. Surprisingly, he did it without the use of a telescope. The result of his study was used afterwards by Johannes Kepler, the German astronomer and mathematician who designed the Law of Planetary Motion. By studying the axis and motion of Mars, he learned that Mars orbit around the Sun in an elliptical path, which is contrary to what they knew beforehand (that each planet’s orbit is a circle). The new idea brought by Kepler, lead to the discovery that all planetary orbits are elliptical.. In 1609, Galileo Galilei used the telescope for the first time to observe Mars. Its history continued. Canals, canyons and other formations that can also be seen on Earth were found to be present in Mars. Ice was discovered on its poles, and it meant water may also be flowing somewhere in the planet. Further on, life is thought to exist or have existed in the planet.

In a nutshell, Mars was not discovered. It was a regular visitor of the wide sky, bright and red as it is. Thus, anyone from primitive times could have seen it. Who knows, the first people on Earth could have. It could have frightened ancient people because of its color. It may have signaled the coming of war as an omen to an old tribe. It surely has puzzled sky gazers until science explained what it really is.

A black hole is an invisible object or a region of space in the universe that has such a strong gravitational force that nothing can escape it. Many astronomers believe that there are millions of black holes in the universe. They are invisible because of the fact that they trap anything, even the fastest thing there is – light. The gravity in a black hole is extremely powerful that it can compress tremendous amounts of matter into an unbelievably tiny space. If the earth will be caught by a black hole, it will be packed into a space as small as a marble.

Their formation is believed to start when an enormous body such as a star runs out of nuclear or internal fuel. This decreases its internal pressure, which eventually causes it to have weak resistance to its own gravitational force. When this reaction is not stopped, it then collapses under its own pressure into a black hole. A gigantic explosion happens where the star throws off its outer layers and its core collapses. This occurrence is called ‘gravitational collapse’ and is the reason for the formation of most stellar mass black holes. However, very few stars become black holes when they die. Most massive stars disintegrate to become neutron stars. Neutron stars are dense stars made up mostly of neutrons.

Anything that strays past the event horizon of a black hole will have uncontrollable direction. Its path will inevitably be aimed towards the black hole and there is no escape whatsoever. Researchers found that captured matter inside the black hole is not kept forever, but deteriorates due to the thermal energy that the black hole emits.

John Michell was the first to propose the possibility of the existence of an object with a gravitational force so strong that it can capture anything including light in 1783. He is an amateur British astronomer.

Albert Einstein’s theory of gravitation, also known as ‘general relativity’ best describes how a black hole is created. It predicts that a black hole formed by the collapse of a star is about 100,000 times bigger than the sun and almost featureless. It reasons that nothing escapes a black hole’s interior due to its ability to warp the path and space-time in which the object travels.

In space, a black hole, although almost undistinguishable, can be detected through a few techniques. X-ray and gamma rays can be emitted from a spacecraft to determine where a black hole could be present. The exact location may then be learned by a method called ‘gravitational lensing’. A band of light is emitted and expected to bend if it will pass through an object with strong gravitational force. A black hole’s force will warp the space-time of the section of light that passes it and makes its existence known.

Studies have shown that every ‘active galaxy’ has an extremely huge black hole in its center. An active galaxy is a galaxy found to have bizarre characteristics. It has a compact region in its center that has much higher brightness over all possible electromagnetic frequencies. These central black
holes may be millions or billions of times larger than the sun.

Neptune possesses a set of five rings. William Lassell was the first to have thought of it but the idea was not further explored. The first official detection was made in 1983 during a stellar occultation from Earth. Exploration was then initiated by Voyager 2 in 1989 and images made by the explorers confirmed the issue. The rings that made up the system were vague, dusty and faint.

The rings of Neptune consist of very dark material which can be compared to organic compounds processed by radiation. The composition could include ice. The rings were found similar to those of Uranus. The rings have huge quantities of dust and the proportion was between 20 and 70%, almost similar to Jupiterian rings which contain 50%-100% of dust. The rings are red in color, transparent and thin. Their normal optical depths are low and are less than 0.1. It is believed that the rings of Neptune are younger than the age of the Solar System itself.

The five rings of Neptune were distinct and clear in the images taken by Voyager 2. In order of decreasing distance from Neptune, the names of the Neptunian rings are Adams, Arago, Lassell, Leverrier and Galle – the names of astronomers who contributed to the discovery and study of the planet. A sixth unnamed ring intervenes with the orbit of Galatea,one of Neptune’s moons. Theother three moons, Thalassa, Despina ad Naiad orbit freely between Galle(innermost) and Leverrier(second from planet).

The outermost ring, Adams, is divided into 5 bright arcs, namely Fraternité,Egalite 1 and 2, Liberté, and Courage. The first three names were taken from the words ‘fraternity’, equality and liberty, after the motto of the French Revolution. They occupy a small range of orbital longitudes and have only just moved slightly from their initial position in 1980. Scientists debated on how these arcs remain as they are, for the reason that the arcs should have spread out in uniform manner overtime as predicted by the law of motion. Neptune’s moon Galatea, just inside the ring, is now believed to affect the confinement ofthe arcs.

The rings of Neptune are well-defined. LeVerrier, Arago and Adam are narrow,with widths of about 100km or less. The other two are broad. They are between2000 and 5000km wide. The innermost ring was named after the man who first saw the planet through a telescope, Johann Gottfried Galle. This ring is faint, has a depth of .15km and an optical depth of 10-4. Dust composition is between 40 to 70%.

The second ring got its name from Urbain Le Verrier, who predicted Neptune’s position through mathematical equations in 1846. The radius of its orbit is about 53,200km but has a width of about 113km. The amount of dust present in the Leverrier ring is between 40 to 70%. The moon Despina which just orbits inward the ring could be guiding it to be confine.

The Lassell, also called ‘plateau’ ring, is the broadest ring of all the five Neptunian rings. It is named after William Lassell who discovered Neptune’s largest moon. The Arago ring, positioned next to the outermost ring is seen as a thin band of light. It is named after Francois Arago, a French, Mathematician, Scientist and Politician.

Mars was named after the ancient Roman god of war ‘Ares’ (AIR eez) and it is believed that Romans and Greeks came up with the name because of the planet’s apparent color, which is ‘red’. It is the fourth planet from the sun and one of Earth’s an-orbit-away neighbors. Among the planets, it’s been the most controversial because of the fact that many theories have been made in account to the possibility that there had been or there is life in Mars. This theory, in a way, is connected to the reason why the planet has the color of war.

Being not exactly and completely red, it is seen as a reddish orange or butterscotch yellow ball using a telescope. From afar, it has patches of darker orange or red areas and other irregularities. Like the earth which has changed itself over centuries, Mars structured itself to give way to mountains, terrains, canyons and canals. The Martian exterior has outstanding features, including a canyon system that is way grandiose than the Grand Canyon in the United States. Interestingly, water is believed to have flowed on the valleys, channels and gullies in the earth-like planet. Even immense quantities of ice were found during one of many explorations which have tried to unravel this mysterious planet. Till now, some scientists believe that water could still be present beneath Mars’ surface.

The main reason why the planet appears to be red is the abundance of iron in the planet’s soil. But this is not enough reason according to many, since iron is also present on the Moon’s soil but it has never become red. A speculation says that Mars, although much colder than the earth (as low as about -195 degrees F (-125 degrees C) or about -80 degrees F (-60 degrees C) on average), could have been wetter and warmer in its early stages. Rocks rich in iron could have been washed and worn away by rivers, seas or any form of water that could have been present in Mars. The oxygen in the water could have combined with iron in these rocks which resulted into iron oxides. Basically, this is what happens when iron gets in contact with water, it forms ‘rust’ which is naturally red in colour. What else happens to rocks when put under different kinds of temperature? They weather or decompose. More theories claim that the decomposed particles which contain iron could have went up to the atmosphere and rained over the soil of Mars. Other stories say that Mars was once flooded with water and this has made iron oxide profuse on the planet.

Spacecrafts have testified to the natural color of its soil. Man has never set foot on it and the assumption that life is present in Mars still continues. The color of the planet is a fact and it is true that Iron oxide or rust is what’s responsible. However, the reason why there is plenty of it in the red planet is still being assumed.

In many ways, Neptune (the 7th planet) and Uranus (the 8th planet) are considered twins. They are nearly identical in size and structure. Neptune is 17times the mass of earth while Uranus is about 15. While at first glance, Neptune and Uranus appear to be smaller versions of Saturn and Uranus, they are poles apart from their giant gas neighbors. These two planets are very distant from the sun and this allows them to cool below the freezing point of the compounds that they are made of. Elements that are abundant in the planet are oxygen,nitrogen and carbon and there are also small quantities of hydrogen, silicates and helium. Water, methane ice and hydrogen are widely present in the planet. Being the only planets in the solar system made up of mostly ice and covered bythin hydrogen atmospheres, these two are called Ice Giants.

The structure of their atmospheres allows sunlight to be unfiltered by theouter layer and springs off the cloud tops below. Methane makes up most of theatmosphere and it robustly absorbs red and orange light. This nature lets bluelight pass through and makes both Uranus and Neptune bluish-green in color.

Although their outer make-up are almost the same, their internal compositions are very different. Uranus has no internal heat which makes it virtually featureless when seen from the earth by the naked eye. On the other hand,Neptune has a burning core and an active and dynamic atmosphere. Like Jupiter and Saturn, and despite being made of different compounds compared with these gas planets, Neptune radiates about 2.7 times as much energy as it receives from the Sun. Dark, elliptical and cyclonic storms occur in the skies of Neptune and in fact, one called the Dark Great Spot, a great storm, appeared on the planet from the 1980’s to 1995. Neptune and Uranus were both unknown to ancient astronomers. Uranus was the first planet to be discovered in modern times and it was by William Herschel while he was systematically searching the sky using his telescope on March 13,1781. His sighting was officially the first since many who had seen it before him just took it as simply another star. It was John Flam steed who first saw Uranus in 1960 and cataloged it as 34 Tauri. Neptune was discovered in 1846,interestingly, through mathematical prediction by Urbain Le Verrier.

They both have weird and off-center magnetic fields. Uranus has the samemagnetic field strength as Neptune. Uranus’ axis of field (an imaginary lineconnecting its north and south poles) is tilted 59 degrees from its axis of rotation.

Neptune’s axis is not perpendicular to the path where it revolves in around the sun. It is tilted at about 28 degrees and it spins around in about 16 hours and 7 minutes. Uranus on the other hand, has its axis tilted to the side at 98degrees which makes many astronomers think that a smaller planet could have knocked Uranus to its side soon after its birth.

Furthermore, Uranus and Neptune are different when it comes to the number of satellites they have. Uranus has 21 known satellites while Neptune has 11. Both planets have outer rings. Uranus has a
number of rings around it in which only ten are dark and narrow. They range from less than 3 miles to 60 miles wide.Neptune, however, has 3 prominent rings and one that is less obvious.

Neptune is known to possess thirteen moons. The planet has the greatest “hill sphere” or gravitational sphere of influence among all the other planets in the solar system. It is most likely because of its immense distance from the sun. The moons of Neptune had been the object of controversies due to their strangely uneven mass distribution. The biggest moon which is Triton makes up 97.7% of the total mass of the whole Neptunian moon system and the rest is made up by the other 12 moons altogether.

The largest and the first to be discovered satellite is Triton. Its radius of 2,706.8 km long makes it belong to the seven moons in the solar system which is larger than Pluto. Its discovery by William Lassel in 1846 was just seven days late than the first official sighting of its orbited planet. There are few different theories that scientists have brought up regarding the origin of Triton. Since it is large and massive enough that it is able to have adequate hydrostatic equilibrium, it was said that it could be a dwarf planet if only it was orbiting the Sun. Uniquely, Triton spins against the direction that Neptune revolves in. This means that it possibly could have been orbiting the Sun before it was captured by Neptune. Furthermore, an idea was brought up that Triton could be part of a three-body encounter. Triton might have existed with a binary planet (like Pluto and its largest moon Charon); the pair could have wandered too close to Neptune and caused Triton to be caught by Neptune’s gravitational force. Likely, the other satellites of Neptune could be the rubbles that resulted from the possibly chaotic capture of Triton. The known ways of how a planet normally captures a satellite can hardly be applied to Triton because of its hugeness and strange orbital motion. Moreover, this moon may have an active core. This can be proven by the ice and geysers present on its surface. These geysers shoot ice 8km high towards Triton’s narrow atmosphere. The presence of ice leads to the thinking that water and even life may be present.

There are 6 regular satellites inward of Triton. Some of them orbit among Neptune’s rings. Naiad, Thalassa and Despina orbits in between the rings. The second moon found is Nereid. It was discovered in 1949 by Gerard Kuiper. It’s one of the six irregular outer moons of Neptune. These outer moons have high inclinations and their orbits are a mixture of prograde and retrograde. Despina, Galatea, Larissa, Naiad, Proteus and Thalassa were sighted by the spacecraft Voyager 2 in 1989. The other five moons were just found recently; three in 2002 and two more in 2003. Psamathe and Neso, found in 2002 and 2003 respectively, have the widest orbits among all the satellites in the solar system – that is, about 125 times the distance between the Earth and the Moon. They are large enough that these two satellites would take 25 years for them to orbit around Neptune.

Neptune’s moons are named after aquatic idols in Greek and Roman mythology. Most of them are names of sea nymphs or “Nereids”. It is in keeping with Neptune’s position as god of the sea.

Neptune, the eighth planet from the Sun, was named after ‘Neptune’, the Roman god of the sea. The official name did not come from Romans or people from the ancient times since Neptune was discovered during the modern times, several decades after Uranus’ discovery.

It was included in Galileo’s drawings which he made when he first observed the planet on December 28, 1612 and January 27, 1613. However, Galileo regarded the planet as a stationary star and he was not credited for its discovery. The detection of Neptune as a planet is different from those of the other planets in the solar system. Neptune was first discovered not by the use of a telescope but by a prediction made by John Couch Adams. His study started when scientists noticed that Uranus, the (the 7th planet and neighbor of Neptune), is not always orbiting in the path that they’ve predicted. Thus, they have thought that another celestial body could be affecting its movement by means of gravitation pull. Adams calculated and proposed the possible orbit of another still to be found planet that causes the change in Uranus’ movement. The result was forwarded to Sir George Airy who asked Adams to give further clarification. Adams tried to formulate a reply but failed to send it to Airy. Another study was separately conducted by Urbain Joseph Le Verrier and he predicted the mass and position of the unknown planet. There was difficulty in getting support and belief from fellow astronomers but in June 1846, George Airy discovered the similarities in the calculations made by Adams and Le Verrier. The search for the planet was initiated by James Challis of the Cambridge observatory but his initial efforts were futile. Le Verrier requested Johann Gottfried Galle to research the planet using the Berlin Observatory’s refractor. It was on the same day of the receipt of the request that Neptune was officially sighted, fairly close from the position where Le Verrier thought it would be. Le Verrier received the credit for the discovery since historians suggested that Adams theory didn’t predict the exact location of the planet.

“The planet exterior to Uranus” and “Le Verrier’s planet” were the names first associated with Neptune. Galle was the first to suggest an official name and he proposed that the planet be called Janus, after the Roman god of gates. Challis also made a suggestion for the name Oceanus. But since Le Verrier had rights to his discovery, he immediately proposed the name Neptune. He afterward tried to name it after himself, to be called Le Verrier, and he received support from the observatory director, Francois Arago. Contrarily, the proposal of naming it after Le Verrier was strongly discarded by authorities outside France since Uranus should have been named Herschel after its French discoverer William Herschel. Friedrich Georg Wilhelm von Struve, a Baltic-German astronomer worded out his favor for the name ‘Neptune’ on December 29, 1846 to the Saint Petersburg Academy of Sciences. The name ‘Neptune’ was considered more appropriate and in line with the nomenclature of the other discovered planets.

Jupiter’s or Jovian moons are as interesting as the planet they orbit on. Officially, 49 moons have been named. Other anonymous asteroid-like satellites have been discovered alongside giving it a total of 63. It is not surprising for Jupiter to have this number of satellites since it is just natural for an extremely massive planet to have such a strong magnetic field that may capture any small body that gets close enough to it. All of the Jovian moons were named after mythical characters who according to Greek stories were Zeus’ mistresses. Zeus is the Greek god version of Jupiter, the Roman god after whom the planet Jupiter got its name.

The four largest moons are called Galilean satellites. Galileo Galilei discovered them in 1610 using the primitive telescope. Simon Marius disputed this and claimed that he saw the satellites at the same time Galileo did but was not just able to officially publish his discovery. The credit went to Galileo.
These moons were named Io, Europa, Ganymede and Callisto. They are all different from each other, each with astonishing characteristics of their own.

Io, the fourth largest moon in the solar system, is a geologically dynamic satellite. It is globally covered with sulfur. It is the most geologically active object that has been discovered in the solar system. Jupiter’s gravitational pull causes Io’s internal burning core to produce intense volcanic activities all over the satellite’s surface and dry up any quantity of water present in the moon. A geyser-like eruption was photographed by NASA’s Galileo spacecraft in June 28,1996 when it made its flyby to Io. One volcano erupted and shot blue, glow-in-the-dark plume 100 kilometers into space and the color was due to the mixture of sulfur dioxide gas and snow that condensed from the gas as the plume spreads out and cools. Even the most active volcano on Earth cannot compete with that. Io has all of its areas filled with thermal activities, shooting out different colors and forms every hour.

Europa is a completely different world. The whole satellite is covered with ice and it is thought that there may be a deep sea of water and slushy ice underneath. This then leads to the controversy among astrobiologists about the possibility of life thriving in it.

Ganymede is the largest moon in the solar system. It is even larger than Mercury. Unlike other moons, it is able to internally generate its own magnetic field. Callisto is the oldest among the Galilean moons. It is significantly cratered and ancient.

The structures of Io, Europa and Ganymede are almost just like that of the Earth. Io has a scorching core, a mantle of molten rock, and a crust of solid rock mixed with sulfur. Europa and Ganymede also have cores, a rocky mantle around the core, another deep layer of soft ice and a narrow crust of ice. Callisto’s layers are not distinct but its composition seems to be mostly a combination of rock and ice.

The rest of the moons include regular and irregular types. Future explorations to Jupiter may even lead to the discovery of more moons.