SCIENCE STUDY GUIDE: Scale of Space, Telescopes and the Electromagnetic Spectrum Cosmic Address Facts: A solar system is smaller than a galaxy, which is smaller than a universe. (solar system << galaxy << universe) The sun is at the center of our solar system. Our barred-spiral galaxy’s name is Milky Way. (“Via Lactea”) There are between 100 – 200 billion stars in our galaxy. We live in: Local Group > Virgo Cluster > Laniakea Supercluster. Drake Equation Facts: Frank Drake developed the equation in 1961. Radio Telescopes are being used to look for alien broadcasts. SETI stands for “Search for Extra Terrestrial Intelligence.” In the Drake Equation, N = the number of technologically advanced civilizations in our galaxy. Voyager I and II spacecrafts were launched in 1977, exited our solar system in 2012, and will keep travelling through space carrying information about our planet. (on the golden record) The first “exoplanet” (Pegasi 51b) outside our solar system was discovered in 1995. There are currently over 1,918 exoplanets that have been discovered (as of January 2016). The zone around a star in which life could exist on a planet is called the “Goldilocks Zone” or the “Habitable Zone.” The Scale of Space Facts: The distance between the Earth and sun is 93 million miles, or one A.U. (astronomical unit). Large numbers are expressed in “scientific notation” ie: 1 x 10 17 A “Lightyear” is the distance light can travel in one calendar year, which is equal to about six trillion miles. The speed of light is: 186,000 miles per second! One million is expressed as: 1,000,000 One billion is expressed as: 1,000,000,000 One trillion is expressed as: 1,000,000,000,000 Infinity means never-ending (Lemniscus ∞ and Mobius Loop) Telescope Facts: Hans Lippershey invented the “spyglass” in 1608. Galileo used the spyglass idea to create the first official, optical telescope in 1609. It was a refracting telescope that used curved, glass lenses to magnify objects in space. He made some discoveries that lead to his conviction as a heretic. Sir Isaac Newton invented the first reflecting telescope in 1668, which uses mirrors to focus the light. Sir Isaac Newton invented the first spectroscope that is used to analyze the visible part of the spectrum. There is a different type of telescope for each type of radiation in the electromagnetic spectrum. Telescopes are built on mountaintops or in space, to avoid interference by ground-level light and the atmospheric pollution. Electromagnetic Spectrum Facts: The visible part of the EM spectrum includes the colors of the rainbow in this order: Red, Orange, Yellow, Green, Blue, Indigo, Violet. The fictional man’s name used to remember the order of rainbow colors is: Roy G. Biv. The distance from the crest of one wave to the crest of the next wave is called: wavelength. The order of radiation types in the EM spectrum from longest to shortest wavelength is: Radio Waves, Microwaves, Infrared Radiation, Visible Light, Ultraviolet, X-rays, Gamma Rays. Exposure to short wavelength radiation (UV, X-ray, Gamma) is dangerous to human health. Black Holes release X-rays at their poles. Gamma radiation is produced when stars explode as supernovae. Active stars produce UV, visible, IR, micro and radio waves. Infrared radiation is known as heat. Ultraviolet radiation causes skin tan and sun burn. The Incredible Hulk is a superhero that got his super powers from being exposed to gamma rays (science fiction only). Extra Credit: Know about the lives of famous early astronomers.