How did the Universe form? Astronomy The study of the universe, stars, planets and all celestial objects in space. The Big Bang Theory 15-20 Billion years ago all matter & energy was squished into a tiny dot that eventually exploded, forming the Universe. Big bang animation The Big Bang Theory Huge clouds of hydrogen, helium and other matter formed. Dust clouds formed the beginnings of galaxies, stars, planets and other celestial bodies. COSMIC BACKGROUND RADIATION Evidence for the Big Bang Long-wavelength background radiation coming from all directions in the universe Electromagnetic Spectrum emitted by stars Almost all galaxies have a red shift; indicating that the universe is expanding Electromagnetic Spectrum Doppler Effect Change of wavelengths as an object moves toward or away from us. Doppler Effect Objects moving away = red shift, wavelength increases-stretches. Objects moving towards = blue shift, wavelength decreases. Spectra: Doppler Red Shift ‘Away’ Blue Blue Red Red Doppler Blue Shift ‘ to You ’ Blue Red Blue Red Hubble’s Law The Universe is expanding Nearby spots are moving away slowly while distant spots are moving away more rapidly. Light Year Distance light travels in one year (6 trillion miles) ! 1 light year = 1 earth year. Galaxies What galaxy do we live in? Milky Way Galaxy -Billions of stars ! Milky Way Galaxy -Sun is located on one spiral arm. Irregular Galaxy Elliptical Galaxy Spiral Galaxy Galaxies System of billions of stars Classified according to their shape Elliptical galaxies are most common Solar system Sun, stars, planets, moons, comets... Formed about 4.5 billion years ago SUN A star. Provides Earth with heat and light, making life possible. Energy drives ocean currents and weather. Composed of hydrogen and helium. 5 billion years old. SUN Temperatures increases toward its center-12million degrees Kelvin Galileo observed sunspots and discovered Sun rotated. Rotates faster at equator than poles (just like the earth) CLOSURE Hw-UPCO Lab p. 439-441 is Due by TOMORROW!!!