Observing and exploring space Chapter 1.1 Telescopes Part 1

Observing and Exploring Space Why do you think Astronomy is one of the most unique subjects in Science? Astronomers have to observe their subjects at a very large distance Only objects that Astronomers can physically study are meteorites What do Astronomers use to study these distant objects?

Electromagnetic Spectrum Astronomers use the light that travels through space to study the objects in space. Not all light is visible by the naked eye Electromagnetic Spectrum: energy that travels in the form of an wave

Light Light travels at 300,000,000 meters per second 670,000,000 miles per hour Light Year: the distance that light travels in one year 9.5 trillion kilometers

Light What is the closest star to us? Sun 2nd - Proxima Centauri 4.22 light years away Our Galaxy, the Milky Way is roughly 100.000 light years across

Light So, when you look up at space, you are really looking back in time. Why? It takes time for the light of that object to travel to us Andromeda is our closest galaxy 2.5 million light years away When you look at the galaxy you are looking at the light that was given off 2.5 million light years ago

Electromagnetic Waves (EM) Electromagnetic Waves have two parts Electrical Magnetic Both work together to create the wave

Waves Wavelength: is the horizontal distance between two of the same points on the wave Frequency: measures the number of wavelengths that pass a given point

Waves of the Electromagnetic Spectrum Ultraviolet Rays Gamma Rays Radio Waves Infrared Rays Visible Light X-Rays Microwaves

Electromagnetic Spectrum Visible light is the only and small part of the spectrum that humans can see Includes all the colors organized by wavelength size

Electromagnetic Spectrum Facts Some very hot stars emit light primarily at Ultraviolet wavelengths Extremely hot objects emit X-rays and gamma rays Cool stars shine mainly in infrared light Faintest and most distant objects come in the form of Radio waves