Physical Science

Astronomy

AstronomyReported by: Cheniel Nica RoblesBSBA IISubmitted to: Mrs. Catalina Punzalan

Astronomycame from the Greek wordsastron means "star" and-nomyfromnomos, "law" or "culture" means "law of the stars" or "culture of the stars" depending on the translation.

Astronomy can be considered as the oldest of all sciences. Astronomyis anatural science that is the study ofcelestial objects(such asmoons,planets,stars,nebulae, andgalaxies), thephysics,chemistry, mathematics, andevolution of such objects, and phenomena that originate outside theatmosphere of Earth.

The history of astronomy stretches back in time to the beginnings of civilization

Mankind has always been fascinated by stars.Before the dawn of history someone noticed that certain celestial bodies moved in orderly and predictable paths & astronomy-an-ancient-was born.

The earliest recorded astronomical observations were made by the Chinese, Egyptians, and Babylonians, who however made no real effort to interpret what they saw.

Many important astronomical observations were made by the Greeks during a period of roughly 800 years from 600 BC to AD 200.

It deals with the structure of the solar system which includes the nine planets and their satellites, the sun, the stars, meteors, asteroids and comets.Astronomy is the branch of science which deals with the study of heavenly bodies, their structure and their motion.

In early times, astronomy only comprised the observation and predictions of the motions of objects visible to the naked eye. In some locations, such as Stonehenge early cultures assembled massive artifacts that possibly had some astronomical purpose.

Before tools such as the telescope were invented, early study of the stars had to be conducted from the only vantage points available, namely tall buildings and high ground using the naked eye.

In addition to their ceremonial uses, these observatories could be employed to determine the seasons, an important factor in knowing when to plant crops, as well as in understanding the length of the year.

Thales of Miletus- was the first of the Greek philosophers. He was accredited with the predicting an eclipse in 585 BC.Who were the early astronomers?Aristachus of Samos- was one of the first people to state that the Earth turns on its axis and orbits the Sun.

Erastothenes- was the one who measured the circumference of the earth, which he calculated to be 40,000 km. This is in close agreement with the modern value of 40,007 km.

Nicholaus Copernicus- a Polish astronomer argued that the Sun, not the earth is at the center of the solar system. Claudius Ptolemy- was very popular for his geocentric model of the solar system.

Tycho Brahe- danish astronomer was the last of the great astronomers to rely on the naked eye, & he improved every previous astronomical observations.

Johannes Kepler- first person to show that the planets move around the sun in elliptical obits.Galileo Galilei- an Italian astronomer, developed the astronomical telescope & used it to discover & study many structures in the universe.Sir Isaac Newton-the laws of motion.

Today, astronomy is continuous progression, discovering something new in the universe almost everyday. Scientist have invented the Hubble Space Telescope which could get a clearer view of the structures in the universe. Many space probes have been sent to various planets to study its composition and structure.

Largest Planet- Jupiter, with an equatorial diameter of 88,732 miles. Smallest Planet- Mercury, with an equatorial diameter of 3031 miles.

Some Facts about Space22Densest Planet- Earth, with an average density of about 5 times that of water.Lightest Planet- Saturn, with an average density about 0.72 times that of water.

Closest Star (excluding the sun)- Triple star system Alpha and Proxima Centauri, about 4.3 light years from earth.Most Luminous Star- Sirius or Dogstar.

Largest Asteroid- Ceres, located between Mars & Jupiter, with a diameter of 636 miles.Farthest object visible to the naked eye- Andromeda galaxy, 2.2 million light-years from earth.