Muggle-Made Tools for Astronomy

Chapter 1

🔭 Telescopes

• Function: Magnify distant objects, make them appear brighter.
• Discoveries: Uranus, Neptune, Pluto, asteroids, comets, moons, galaxies, exoplanets.

     Historical Development

• Hans Lippershey (1608): Invented the first telescope (objective lens + concave eyepiece).
• Galileo Galilei (1610): Improved telescope (20x magnification); discovered:
• Jupiter’s 4 moons (Galilean moons)
• Venus phases → proof of heliocentrism
• Kepler: Used two positive lenses → wider field of view but images upside down.

     Types of Telescopes

• Galilean: Positive objective + negative eyepiece → narrow field.
• Astronomical: Both lenses positive → wider field, inverted image.
• Terrestrial: Two positive lenses in eyepiece → upright image.

      Key Concepts

• Refracting Telescopes: Use lenses to bend (refract) light.
• Reflecting Telescopes (Newtonian): Use mirrors → avoid color distortion at edges.
• Magnifying Power = Weak objective + Strong eyepiece.
• Light-Gathering Power ∝ Area of objective:
• 2× diameter = 4× light
• 3× diameter = 9× light

     Resolution

• Sharpness of detail; ability to distinguish close objects.
• Measured in arcseconds (1° = 60 arcmin; 1 arcmin = 60 arcsec).
• Resolution improves as diameter increases.
• Problem: Earth’s atmosphere blurs images (limited to ~1 arcsec).
• Solutions:
• Adaptive optics: Mirror deforms to adjust.
• Space telescopes: Avoid atmosphere.

🛰️ Satellites

• Definition: Objects in orbit; natural (moons) or artificial (human-made).
• Uses:
• GPS, communication, weather, Earth imaging, space observation.
• Hubble Telescope:
• Launched 1990 (2.5m wide), corrected in 1993 (flawed mirror).
• Discoveries: galaxies, black holes, accelerated expansion of universe.

🌍 Space Race

• Soviet Union:
• Sputnik (1957) – First satellite.
• Laika – First animal in space.
• Yuri Gagarin (1961) – First human.
• Valentina Tereshkova (1963) – First woman in space.
• USA:
• NASA founded (1958).
• Apollo 11 (1969) – First Moon landing (Armstrong, Aldrin, Collins).

🌐 Global Space Agencies

• ESA, CNSA (China), ISRO (India), JAXA (Japan), CSA (Canada).
• ISS: International collaboration; wizards have participated under cover (not in NASA due to Rappaport’s Law).
• Canadarm: Robotic arm invented by Canada.

🚀 Space Shuttles

• NASA’s STS (1980s–2011):
• Reusable launch system.
• Launched Hubble, ISS parts, probes.
• Ended after Challenger & Columbia disasters (14 deaths).
• Post-2011: U.S. used Russian Soyuz craft; new U.S. programs launched in 2019.

📡 Radar

• Function: Detects object position & motion using radio/microwaves.
• Analogy: Like bouncing balls off a wall.
• Astronomical Uses: Studying surfaces of Moon, planets, moons, asteroids.
• Applications: Air/sea navigation, military, weather, mapping.

🤖 Rovers

• Definition: Vehicles that explore surfaces of planets/moons.
• Types:
• Human-transporting or robotic (remote or self-driving).
• Destinations: Moon & Mars.
• Key Rover: Curiosity (U.S.) – Searching for life on Mars.
• Communication delay:
• Moon: ~1.25 seconds (remote driving possible).
• Mars: 4–24 mins → must be autonomous.