10.1 Development in Astronomy
Astronomy is one of the oldest fields of science, evolving from simple naked-eye observations of sky patterns to the use of highly sophisticated ground-based and space-based technological instruments.
Historical Evolution of Astronomical Models
- Geocentric Model (Claudius Ptolemy): Proposed that Earth is static at the center of the Universe, and the Sun, Moon, and planets revolve around Earth in circular orbits.
- Heliocentric Model (Nicolaus Copernicus): Proposed that the Sun is at the center of the Solar System, and Earth and other planets revolve around the Sun in circular orbits.
- Modified Heliocentric Model (Johannes Kepler): Modified Copernicus's model by establishing that planets revolve around the Sun in elliptical orbits rather than perfect circles (Kepler's Laws of Planetary Motion).
Key Historical Pioneers & Innovations
- Galileo Galilei: First person to use an astronomical telescope (optical refracting telescope) to observe celestial objects in 1609, discovering Jupiter's four largest moons and Saturn's rings.
- Isaac Newton: Invented the reflecting telescope using mirrors to reduce chromatic aberration.
10.2 Development and Technology in Space Exploration
Modern space exploration relies on sophisticated technology to gather data, conduct microgravity research, and deploy artificial satellites.
Key Technological Instruments
- Telescopes:
- Optical Telescopes: Refractors and reflectors (e.g., Mount Palomar Observatory) for visible light.
- Radio Telescopes: Detect radio waves emitted by celestial bodies (e.g., FAST radio telescope).
- Space Telescopes: Placed in orbit above Earth's atmosphere to eliminate atmospheric distortion and absorption (e.g., Hubble Space Telescope, James Webb Space Telescope).
- Rockets: Vehicles propelled by chemical fuel reaction motors used to overcome Earth's gravitational pull and lift payloads (satellites, space probes, shuttles) into space.
- Artificial Satellites: Human-made objects launched into orbit for telecommunications, weather forecasting, GPS navigation, remote sensing, and Earth observation (e.g., TiungSAT, RazakSAT).
- Space Probes: Unmanned spacecraft sent to distant celestial bodies (planets, asteroids, comets) to collect data, photos, and soil samples without returning to Earth (e.g., Voyager 1 and 2, Curiosity Rover).
- Space Stations: Large inhabited satellite platforms in low Earth orbit designed for scientists to live and conduct microgravity research over long durations (e.g., International Space Station - ISS).
- Reusable Launch Systems & Spacecraft: Space Shuttles and modern reusable rockets designed to transport astronauts and equipment to orbit repeatedly, lowering mission costs.
Applications of Remote Sensing Technology
Remote sensing is the technology of acquiring information about Earth's surface from a distance using sensors onboard satellites or aircraft.
- Agriculture: Monitoring crop health, soil moisture levels, and detecting plant diseases.
- Geology & Mining: Mapping mineral deposits, monitoring volcanic eruptions, and detecting earthquake fault lines.
- Disaster Management: Flood monitoring, tracking forest fires, and evaluating tsunami damage.
- Defense & Security: Border surveillance and military intelligence mapping.
- Environmental Monitoring: Tracking deforestation, urban heat islands, and ice cap melting.