# Scale of Space, Telescopes and the Electromagnetic Spectrum

```SCIENCE STUDY GUIDE:
Scale of Space, Telescopes and the Electromagnetic Spectrum
 A solar system is smaller than a galaxy, which is smaller than a
universe. (solar system &lt;&lt; galaxy &lt;&lt; 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 &gt; Virgo Cluster &gt; Laniakea Supercluster.
Drake Equation Facts:
 Frank Drake developed the equation in 1961.
 SETI stands for “Search for Extra Terrestrial Intelligence.”
 In the Drake Equation, N = the number of technologically
 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.
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