Topic 2 Space Exploration Stronger Eyes and Better Numbers Topic 2 Space Exploration

Telescopes Throughout ancient times, the mapping of stars improved However, the Telescope really helped astronomers to see more and understand more

Hubble Space Telescope - Chapter 1

Telescopes Telescope: A device used to magnify objects at great distances Objective Lens: The large lens at the front of a telescope. Ocular Lens / Eyepiece: The lens through which you view a magnified object using a telescope

Telescopes

Telescopes Hans Lippershey (a Dutch spectacle maker) invented the telescope in 1608 Later in that century, Galileo Galilei (an Italian astronomer) improved the telescope and used it to look at celestial objects

Telescopes Note: Galileo was the first to observe the moon’s blemishes, sun spots, Jupiter’s moons, and realized that stars were much further away from us than the planets.

Galileo’s Approach to Inquiry Galileo’s observations supported Copernicus’s Sun- Centred model However, his observations did not support Ptolemy’s Earth-Centred model

Galileo’s Approach to Inquiry Because he was able to see Jupiter’s moons orbiting Jupiter and not Earth, he realized that not all celestial objects orbit Earth and thus disproved Ptolemy’s Earth-Centred model.

Galileo Sun-Centered System

Resolving Power In order to build a more powerful telescope you need to increase its resolving power Resolving Power: Determines the fineness of detail a telescope can produce of an object in view

Resolving Power Resolving power depends on the diameter of the objective lens Smaller Diameter = high magnification Large Diameter = finer detail and high resolving power

Refractors and Reflectors Many different telescopes have been invented since Galileo’s time including the Refracting Telescope and the Reflecting Telescope

Refractors and Reflectors Refracting Telescope: A Telescope that has a lens for its objective

Refractors and Reflectors Reflecting Telescope A Telescope that has a mirror for its objective

Refractors and Reflectors Sir Isaac Newton designed the first Reflecting telescopes to overcome the problem that Refracting telescopes had

Refractors and Reflectors Refracting Telescope Reflecting Telescope Advantage: Give better images Disadvantage: Could not focus different colours in the same place Can focus different colours in the same place Can be made much larger Give poor quality images

Refractors and Reflectors New telescopes have been created that incorporate both types of telescopes into one called Combination or Catadioptric Telescopes

Copernicus’s Sun-Centred Revolution Continues Although Galileo’s telescopic observation helped to confirm Copernicus’s Sun- Centred model of the Universe, Copernicus’s model still needed work

Copernicus’s Sun-Centred Revolution Continues Johannes Kepler: In 1609, Johannes Kepler, a German mathematician, found that the planets’ motions would be more accurate if planetary orbits were elliptical rather than circular

Copernicus’s Sun-Centred Revolution Continues Johannes Kepler: Ellipse: A figure that looks like a squashed circle Planets in the solar system move in elliptical orbits around the Sun

Copernicus’s Sun-Centred Revolution Continues Johannes Kepler: Kepler determined this through mathematics and observation Kepler was given the task of figuring out the orbit Mars using mathematics

Copernicus’s Sun-Centred Revolution Continues Johannes Kepler: Kepler used the star charts of Tycho Brahe (a famous astronomer) and found that the only way to explain Tycho Brahe’s observations of Mars’ orbit around the sun was that it had to be elliptical in shape This work took him two years

Copernicus’s Sun-Centred Revolution Continues Johannes Kepler: Not only did Keplers work determine that orbits are elliptical and not circular, but he also determined the shape and scale of the entire known solar system Brahe and Kepler

Universal Gravitation Aristotle: Used philosophical and geometric models of the universe Kepler: Used mathematical models of the Universe based on more accurate observations of the celestial bodies

Universal Gravitation Isaac Newton: Eighty years after Kepler described the elliptical shape of the planets’ orbits, Isaac Newton stated the law of Universal Gravitation

Universal Gravitation Isaac Newton: Universal Gravitation: Newton’s law states that all objects attract all other objects, and provides an explanation for the planets’ elliptical orbits

Universal Gravitation Isaac Newton: Newton stated that there is a gravitational force between all objects that pulls them together (like a 3- Dimensional dent in space)

Universal Gravitation Isaac Newton: When no force acts on an object it will move in a straight line at a constant speed

Universal Gravitation Isaac Newton: The planets are always in motion, however the force of gravity from the Sun balances their tendency to move in a straight line and results in the planetary orbits.

From Newton to Einstein - The Elegant Universe