Astronomy and Space Exploration


Developments In The Field Of Atronomy

1. Astronomy is a branch of science that studies the motions and natures of planets, stars and galaxies. It is the oldest of all sciences.


2. In many early civilisations, our ancestors noticed that regular changes occured in the arrangements and movements of stars and planets. They used these observations to predict future events, and even wove these changes into their religions and the mythologies. To these people, knowing the behavior of the sky was an essential part of their lives. That is why astronomy, being the study of the universe, was one of the first sciences to develop.


3. The early civilisations of China, Egypt, Greece and Middle East made careful observations and records of the regular motions of the start and planets. They divided the stars into groups or constellations and recorded spectacular phenomena such as comets and eclipses.


4. One of the earliest reasonably good calendars was drawn up by the Egyptians. They paid great attention to the star Sirius which gave a reliable clue to the annual flooding of the Nile.


5. Aristotle, Ptolemy and Pythagoras were ancient Greek astronomers who greatly contributed to the study of astronomy, whereas Aryabhata, Caliph al-Makmun, Umar Khayam, Al-Khawarizmi, Al-Buttani and Al-Biruni were famous ancient astronomers from the east.


6. Aristotle (384 - 322BC) gave the first practical proof that the Earth is a globe.


7. In 200AD, the Greek astronomer Ptolemy, who lived in Alexandria of Egypt, suggested that the Earth was the centre of the universe. Heavenly bodies, including the Moon and the Sun, move with uniform circular motion around the Earth. At that time, most people believed him.


8. The first serious challenge to Ptolemy's theory came in 1543 when Nicolaus Copernicus (1473 - 1543) from Poland claimed that the Sun is the centre of the Solar System and the Earth orbits the Sun.


9. The 17th century produced major developments in astronomy when Hans Lippershey (1570 - 1619) invented the first telescope in 1608.


10. Johannes Kepler (1517 - 1630) postulated that the planets move about the Sun in ellipses and not perfect circles.


11. Galileo Galilei (1564 - 1642) was the first person to use a telescope to make systematic observations and spectacular discoveries. He saw the mountains and craters of the Moon, the phases of Venus, the satellites of Jupiter, the spots of the Sun and the countless stars of the Milky Way.


12. In 1668, the English scientist Isaac Newton used a mirror instead of lenses to collect light in a telescope. The mirror acts like a giant eye, collecting light from faint and distant stars. This reflecting telescope was much shorter and clearer. It is so sensitive that it can detect a single candle 24 000 km away.


13. In 1932, the Americal engineer Karl Jansky invented the radio telescope that heralded the beginning of radio astronomy.


14. Radio telescopes detect radio waves that come from distant start and galaxies. A computer display screen will show the picture of the sky as seen through the 'eyes' of the radio.


15. Human beings then sent telescopes out to space to get a clearer picture of the Universe. Space telescopes provide clearer images without the disturbance of the Earth's atmosphere.


16. The most famous orbiting space telescope is the Hubble Space Telescope. Since then, there have been many other orbiting space telescopes and observatories launched into space. They provide a window to the Universe for Earth-bound astronomers.


17. The 20th century has many other astronomical events. The number of planets was increased to nine in 1930 and Wernher von Braun experimented with rockets two years later.


18. This development enabled the Russians and the Americans to develop space technology and pursue space exploration where human beings are able to send artificial satellites, probes, rockets, space shuttles and people to space.


Developments In Space Exploration

1. The launching of the first artificial satellite, Sputnik 1, on 4th October 1957 by the Russians marked the opening of the space age.


2. Manned space flight began on 1961 when Major Yuri Gagarin of the Soviet Air Force was launched in the spacecraft Vostok 1 and made a full circuit of the Earth before landing safely.


3. On 20 July 1969, Neil A, Armstrong and Edwin E. Aldrin from the United States landed on the Moon in the lunar module, Apollo 11.



4. The job of space exploration is however left to unmanned probes.


5. The most spectacular space probes were the two Voyagers launched in 1977. They were sent on a grand tour of the outer Solar System and its great gas giants: Jupiter, Saturn, Uranus and Neptune. They are now racing towards the outer edge of the Solar system. Voyager 1, now 13.4 billion km away, is the most distant object made by human beings.


6. One vital development of space exploration was the invention of the reusable space shuttle.



7. It was a space shuttle that put the Hubble Space Telescope in orbit.


8. Space station Skylab was set up by the Americans in 1973 and the Russians space station Mir was launched in 1986. Both space stations are not in operation now.


9. The International Space Station was launched in 1998. It provides a platform for scientists to carry out researches in various fields, such as medicine and meteorology.


Application Of Technology Related To Space Exploration

1. Technology has played as essential role in the study of space and the emerging use of space environments.


2. Some people believe that space research and space exploration has no value for human beings. The value of manned space missions has often been questioned and it has been claimed that they are unnecessary and costly.


3. However, space technology and space exploration have resulted in great contribution and applications. One example is the use of artificial satellites.


4. Satellites are designed for

    (a) communications

    (b) weather forecasting

    (c) military purposes and national security management

    (d) remote sensing

    (e) disaster management


5. Communication satellites enhance televisions and radio broadcasting. They provide direct links between continents and are now introducing distance learning to remote areas.


6. Remote sensing is a cost effective, timely and informative technique used to study the Earth and its environment. It provides vital inputs on agriculture, soil, forestry, land and water resources, minerals, ocean development and management of droughts and floods.


The Need To Continue Space Exploration

1. Astronomy and space exploration have wide educational and cultural significance. They are deeply rooted in almost every culture because of its practical applications and philosophical implications.


2. Astronomy shows us a Universe that is vast, varied and beautiful. It helps in the advancement of physics and other sciences by providing a cosmic laboratory with extreme environments such as black hole.


3. Money spent on space research and development is not wasted. It goes towards creating knowledge, jobs, businesses and technology. Space technologies have direct application to other activities such as solar power generation and human-robot interaction.


4. During the Apollo moon landing, we learnt more about the lunar geology and the Solar System. Now, the Hubble Space Telescope has literally changed our understanding of the Universe.


5. If there were no communications satellites, we would not be able to communicate effectively. Closer communication has done a lot to save the Earth, save lives and bring everyone closer.


6. Without weather satellites, there would be little or no warning of disasters such as typhoons and tornadoes that could cause thousands of deaths.


7. We would certainly know less about our Solar System and the Universe without the space probes and orbiting telescopes.


8. We would also understand less about the Earth. its ecological systems and the efficient ways of growing crops and controlling pollution.


9. Therefore, the voyage to the Universe and the unknown should continue to fulfil our desire to learn more, see more and understand more.