Nicolaus Copernicus first proposed that the Earth and planets revolve around the Sun, contradicting the accepted model of Ptolemy and Aristotle of Earth as the center of the universe. Major developments included Galileo's use of the telescope to observe moons orbiting Jupiter and rings around Saturn, and Isaac Newton's formulation of the law of gravity. Modern space exploration began with Sputnik I and has involved satellites providing communication, weather monitoring, navigation, and other applications as well as human missions to orbit and walk on the Moon.

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FORM 3 SCIENCE NOTES
CHAPTER 10 SPACE EXPLORATION
10.1 Developments in the Field of Astronomy and Space Exploration
Developments in the field of astronomy
 Astronomy – Scientific study of motion and nature of objects in Universe.
 Al-Khawarizmi and Umar Khayyam
- Astronomers in Baghdad
- Al-Khawarizmi updated knowledge on astronomy
- Umar Khayyam revised the calendar used at that time
 Aryabhata
- Indian astronomer
- Rotation of Earth on its axis
- Solar and lunar eclipses 日食和月食
 Ptolemy and Aristotle
- Sun. planets and stars orbit Earth 地心说 (Which is wrong)
- This was accepted for over thousand years.
 Nicolaus Copernicus (Father of Modern Astronomy)
- First to show that planets, including Earth, orbit Sun 日心说
- Proved by measurements and mathematical calculations
 Hans Lippershey
- Invented telescope
 Galileo Galilei
- Observed celestial bodies more accurately using telescope
- First to use telescope to make systematic observations of objects on spaces.
- Observe
 Milky Way and its stars
 Mountains and craters 陨石坑 on Moon
 Phases of Venus
 Sunspots
 Four moons orbiting Jupiter
 Rings around Saturn
 Sir Isaac Newton
- Discovered law of gravity
- Sun exerts force because planets orbit Sun along curved paths
- Explain elliptical motion of planets
- Developed mirror telescope
 Less accurate than modern telescope
 Better than lens telescopes of that time)
 Edwin Powell Hubble
- Proved existence of galaxies
- Present evidence for expansion of Universe
- NASA named Hubble Space Telescope after him

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Developments in space exploration
 Space exploration – Investigation of Universe other than Earth by man using spacecraft.
 Rockets: Launch artificial satellites into space
 Spacecraft: Collect and send back information to Earth include sounding rockets, artificial satellites and
interplanetary spacecraft
 Artificial satellites: Collect various kinds of information.
 Interplanetary spacecraft: Explore space by overcoming Earth’s gravitational pull.
 Satellites
- Begin when Russia launched Sputnik I
- Sputnik II with a dog, Laika was launched
 Space probes
- Unmanned spacecraft
- Orbit the Earth
- Have telescopes to gather information and data and send images back to Earth
 Space stations
- First space station was launched by Russians in 1971
- Stay in space for long period. Astronauts carry out scientific work in space stations
 Space shuttles
- Conduct research
- Help repair and recover damaged satellites
 Human beings
- In 1961, Russia sent Yuri Gagarin to orbit Earth. (First astronaut to orbit Earth)
- First woman in space: Valentina Nikolayeva-Tereshkova (1963)
- 1969: Apollo II launched by Americans landed on Moon, Neil Armstrong was first human being to
step foot on Moon.
Application of technology in space exploration and astronomy
 Biggest application of technology: Satellites
 Telecommunication
- Communication satellites enhance global communications and provide direct links between
continents.
- Orbit Earth once in twenty four hours.
- In Malaysia, MEASAT satellites in space transmit live telecasts to televisions in homes
 Navigation
- Navigation satellites guide ships at sea and flying aircraft to determine their positions and directions.
- Global Positioning System plays an important role in search and rescue missions.
 Military purposes
- Military satellites help countries improve security and defence.
 Weather forecasting
- Weather satellites detect and monitor changes in weather condition.
- Essential part of weather forecasts.
- Provide meteorologists with more accurate images of cloud and storm patterns.

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 Mapping of natural resources
- Environmental satellites help detect locations of natural resources.
- Survey suitable agricultural land, water sources and forest fires.
 Remote sensing
- Collect data and information in space about the conditions and activities on Earth.
Field Applications
Geology
 Locate natural resources
 Map locations rich in minerals
Agriculture
 Map soil that is suitable
 Monitor soil conditions
Forestry
 Monitor deforestation and illegal logging
 Monitor conditions of forests
Water resources
 Detect underground resources
 Monitor water catchment areas
Disaster management
 Detect oil spills and forest fires
 Detect open burning
Weather forecasting  Predict weather hazards
Marine
 Select aquaculture sites
 Detect marine life
The various applications of remote sensing
Developments in space exploration
 Weather satellites
- Provide information such as cloud cover, storm location, temperature in atmosphere and movements
of air masses.
- It monitors whole weather systems to allow advanced warning of storms and typhoons.
Weather satellite

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 Communication satellites
- Purpose of telecommunication.
- Includes television and radio broadcasting, communications to ships and planes.
 Navigation satellite
- Provide vital positioning information.
- Guiding military fighter through skies, Helping lost sailors
 MEASAT geostationary satellites
- Direct-to-user television service and general communication service.
Communication satellite
Navigation satellite
MEASAT-3

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 Space station
- Base for astronomical observations, refueling and repair.
- The only space station: International Space Station
 Space probe
- Carries sophisticated instruments on board and navigates among planets
 Space telescope
- Provide clearest view of distant stars and galaxies in Universe.
Justifying the need to continue space exploration
 Curiosity about Universe
 Scientists have developed more advanced instruments and spacecraft
 Many benefits derived from space exploration
International Space Station
Space probe
Space telescope