Astronomy Review

• Electromagnetic Waves are all types of light
• The speed of all EM waves is the same through the space( 300,000,000 m/s)
• Light year- how we measure distances in space, the distance light travels in one year.
• Telescopes let us see objects far away.
• Different telescopes "see" all the different types of EM waves.
• The telescope is the one in space named the Hubble telescope.
• Space Probes- unmanned missions sent to explore our solar system.
• Manned Space Missions- 12 people have been on the moon
• 676 people have in space.
• Stars are not burning
• Stars are doing nuclear reactions that turn hydrogen into helium- this releases energy.
• Core of the Star- where nuclear reactions use up 4 hydrogen to make a helium.
• Mass is converted to energy by the process of nuclear fusion.
• There is gravity in space
• The force of gravity increases with mass
• The force of gravity decreases with distance
• An inverse square law

  
• Orbits of planets and satellites are a balance between speed and the force of gravity.
• Spectral Analysis- when observing the light spectrum of a star, we can know the elements in a star.
• Star Evolution- as star use up their hydrogen, they change color, size, and composition.
• Stars with less mass last longer.
• Hubble Space telescope scans the entire galaxy and we find stars in all stages
• Newton's Law of Gravitation: Fg=Gm1 x m2/ d2
• A planet's orbital speed changes, depending on how far it is from the Sun.
• The closer a planet is to the Sun, the stronger the Sun's gravitational pull on it, and the faster the planet moves
• The farther it is from the Sun, the weaker the Sun's gravitational pull, and the slower it moves in its orbit.
• Our Solar System formed about 4.5 billion years ago from a dense cloud of installer gas and dust.
• Rocky Planets: Mercury, Venus, Earth, and Mars.
• Gas Planets: Jupiter, Saturn, Uranus, and Neptune.
• Stars produce their own light and energy through a process called nuclear fusion.
• The size of the universe is 92 billion light-years across.
• Dark Energy- scientists don't know it yet but it's there, it makes the universe expands at an accelerating rate.
• Dark Matter- stuff in space that has gravity and makes up 27 percent of the universe
• Doppler Effect- the increase or decrease in frequency of a wave as it moves towards or away from the observer.
• Redshift means that the object is moving away from us
• Blueshift means it's moving closer towards us
• Big Bang Theory: The universe began as a singularity, which expanded and cooled down.
• Universe Expanding Theory- scientists believe that the universe is expanding because of dark matter and dark energy and that the universe is expanding faster than it was in the past
• Nebula to low mass star to main sequence to red giant to planetary nova to white dwarf to black dwarf.
• Nebula to high mass star to main sequence to red super giant to super nova to black hole or neutron star