Another term that is used to refer to earth science is Geo-science. It is a term that incorporates all sciences related to the planet earth. The discipline of earth science incorporates the study of the Hydrosphere, atmosphere, oceans and biosphere. The study of the earth may as well be included. To create a descriptive understanding of how the earth works, and its evolution to its current state, the earth scientists use tools from chemistry, physics, biology, mathematics and chronology.
1. The universe is defined as the total of everything that exists. The geocentric model, also known as geocentricism, states that the universe has its centre as the Earth and all other objects orbit around it. This model was used predominantly in cosmological systems in some ancient civilizations, for example in ancient Greece. However, ancient Greek philosophers considered that the sun, moon, stars and planets orbit the earth.
Two observations made supported the idea that the Planet Earth was right at the centre of the universe. The stars, sun and planets appear to orbit around the earth each day making the earth the centre of that system. Furthermore, every star was on a celestial sphere of which the centre was the earth, which rotated each day, using a line through the North and the South Pole as an axis. The second notion supporting the geocentric model was that the earth does not seem to go from the viewpoint of an earth bound observer and that it is stable, solid and unmoving.
Claudius Ptolemy lived in Rome. His model of the solar system was an improvement of previous models by Greek astronomers. First and foremost, Ptolemy's model assumed that the earth was what constituted the entire universe. Ptolemy assumed that every planet moved on an epicycle. An epicycle was a small circle which was orbited by the earth, according to Ptolemy's model. The epicycle, in turn, was thought to orbit a larger circle referred to as a deferent.
2. Minor members of the solar system include those planets that are made up of rock and metal as their principal components. They can also be referred to as terrestrial planets. These planets include Mercury and Venus
3. Nicolaus Copernicus made an argument on the theory that the Planet Earth was not the centre of the universe and that both the earth and the other planets of the solar system orbited the sun. The Catholic Church deemed him an independent thinker for his belief, only until much later for it to be proved true by science. He was born on 19th February 1473, died 14th May 1543. His book on the revolutions of the essential spheres that was published just before his death in 1543 is regarded as the starting point of modern astronomy. Copernicus was a master in several fields, being an astronomer, mathematician, jurist, physician, classics scholar among many others.
Tycho Brahe, a Danish noble man, lived in the period 1546-1601. His contributions to astronomy went a long way being extremely crucial through devising the most precise instruments even before the invention of the telescope. He made his observation of the heavens from an island between Denmark and Sweden called Hveen. Brahe's instruments allowed him to determine all the motions of the planets quite accurately.
Johannes Kepler (1571-1630) was a German who went to become Brahe's assistant in Parague. On the one hand, Brahe mistrusted Kepler with fear that he would take credit for his work and overshadow him. Kepler had the task of observing and understanding the orbit of the planet Mars which had become troublesome to Brahe. On the other hand, the Martian data allowed Kepler to correctly formulate the laws on planetary motion.
Galileo Galilei (1564-1642). His contributions are appreciated both in astronomy and physics. Galileo Galilei had a significant role in astronomy. Galileo provided crucial observations that proved the Copernican hypothesis. His observations also laid the foundations for understanding correctly how objects move on the earth's surface and relation to gravity. Galileo also invented the telescope.
Isaac Newton (1642-1724). He came to being the same year that Galileo died. He completed the synthesis of astronomy and physics that Galileo had began. His fields of expertise include physics, astronomy, mathematics, philosophy and theology. Newton described Universal gravity and the three laws of motion which were dominant in the scientific view of the universe. Isaac Newton showed that objects in motion on the earth and celestial bodies are governed by the same set of natural laws.
4. The criteria used to determine whether a planet is a Jovian or Terrestrial includes distance, whereby Jovian planets are usually further away the sun that terrestrial planets, size, Jovian planets are also much larger than terrestrial planets, density, terrestrial planets have low masses as compared to Jovian planets. Jovian planets are made up of hydrogen and helium, while terrestrial planets mainly have carbon dioxide and nitrogen.
Mercury is the planet which is close to the sun. It’s not easily visible because its orbit lies so close to the sun. Its revolution round the sun is only 88 days. It has a magnetic field that is weak. 65 percent of the planet is metallic core, making it far denser than earth.
Venus- It’s the second closest planet to the sun. It is located between the earth and Mercury. The planet means beauty and love. The meaning is derived from the Roman goddess. It is covered with thick clouds that create a greenhouse effect that makes it exceedingly hot.
The planet Earth is the third closest to the sun. It is made up of three components, Mantle, Crust and Core. Its atmosphere is made up of gases like Nitrogen, Oxygen, Carbon dioxide and methane gas. Its surface is comprised of land and water. The water bodies include seas and oceans. The planet Mars was named in reference to the Roman god of war. The meaning is due to its reddish appearance.
5. Stellar Parallax can be explained as the difference in the orientation of a celestial object as seen by somebody observing from two separated positions or points. A parallax is a measure directly from the distance of the body from the earth (geocentric parallax) and from the sun (heliocentric parallax). The position of the object and the two positions of the observer form a triangle. When determining a celestial distance by the parallax measurement, to get the biggest precision of measurement, the main line is often taken to be as long as possible.
6. The earth's moon is one of the natural satellites to the earth. It is more than one quarter of the size of the planet earth. Due to its small size in nature, its gravity is one sixth of the earth’s gravity. The moon has two basic types of regions. One region is smooth, dark mare and a heavily-centered light colored highland region. The moon has many surface features such as mountain ranges, craters, lava plains and riles. Lunar geologists believe that the earth's interior is made up of a small iron core and it has no magnetic field. The moon has no wind and thus no atmosphere. Being so, it has no weather patterns.
9. The White dwarf is an extremely small and hot star. The White dwarf is in the last stage, in the life cycle of a star. White dwarfs are similar to the Sun when their masses are compared, but they differ in terms of diameter. White dwarfs have a small diameter, almost the same as that of the planet earth. White dwarfs have high surface temperatures of 8000 degrees Celsius.
White dwarfs are the remains of normal stars, whose energy supplies have been exhausted. White dwarf consists of high density hot matter brought about by gravitational forces. White dwarfs aloof and fade over billions of years. Red giants are big, bright stars with a cool surface. A red giant is formed during the final stages of the development of a star such as the sun. Red giants have diameters of between 10 and 100 times. They are very bright because they are very large. Their surface temperature is lower than that of the Sun, about 2000-3000 degrees Celsius.
10. The Big Bang theory tries to explain happened at the beginning of the universe. Advancements in astronomy and physics have shown beyond any doubt that the universe did, in fact, have a beginning. Prior to the beginning, there was nothing, and after the big bang, the universe came to being.
According to this theory, our universe sprang into existence around 13.7 billion years ago. Singularities are things which defy the current understanding of physics. Singularities have been believed to exist in black holes. Black holes are points in space time with very strong gravitational field. The gravitational field is believed to be strong enough to prevent light from escaping. The universe is supposed to have begun as an infinitely dense, infinitely hot small something - a singularity.
After its appearance, it expanded (big bang) and cooled. It thus went from a very small and hot infinite matter, to the size and temperature of the present world. It keeps on enlarging and cooling to this day.