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Meade ETX-90EC Appendix E YOU AND THE UNIVERSE, The distance from the Earth to the Moon

Models: ETX-90EC

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	Appendix E: YOU AND THE UNIVERSE

APPENDIX

The distance from the Earth to the Moon

Radius = 239,000 miles

The distances between the planets

The distance from the Earth to the Sun is 93 million miles or 1 Astronomical Unit (AU)

Pluto’s elliptical orbitis eccentric and carriesthe planet inside theorbit ofNeptune at itsclosest approachto theSun.

The distance between stars

The distance from the Sun to the nearest star is about 4.3 light-years, or 25 trillion miles. This distance is so large that if a scale model were created with the Earth one inch away from the Sun, the nearest star would have to be placed over 4 miles away!

Approximately one hundred billion stars, including the Sun, comprise the Milky Way Galaxy, which is a spiral-shaped

collection of stars believed to be more than 100,000 light years in diameter.

The distances between galaxies

Milky Way Galaxy

Andromeda Galaxy (M31)

Whirlpool Galaxy (M51)

The Sun

2.2 million light-years		35 million light-years

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Meade ETX-90EC Appendix E YOU AND THE UNIVERSE, The distance from the Earth to the Moon, The distances between the planets

Contents

ETX-90EC Astro Telescope ETX-125EC Astro Telescope Instruction ManualMeade Instruments Corporation 1. Eyepiece 2. Viewfinder Chapter 2 Telescope Fundamentals CONTENTSz3Chapter 5 Optional Accessories Chapter 6 Maintenance and Servicing Appendix A Tracking Motor SpeedGUIDE Slew SpeedParts List Chapter 1 GETTING STARTEDAssembly Instructions OPTIONAL ACCESSORIES, pageTelescope Controls GETTING STARTEDTELESCOPE FEATURES Quick Tips Computer Control PanelACCESSORIES , page GETTING STARTEDzIndicator Light Key Light NoETX-90EC GETTING STARTEDETX-90EC 8 x 21mm Erect-Image Viewfinder ETX-125EC1900mm Power = = 26mm Chapter 2TELESCOPE FUNDAMENTALSTelescope Focal Length Power = Eyepiece Focal Length TELESCOPE FUNDAMENTALS THE ELECTRONIC CONTROLLER TELESCOPE FUNDAMENTALSz1. Complete the Polar Alignment Procedure on page Modes of OperationLocating the Celestial Pole Polar Alignment ProcedureCelestial Coordinates High-Latitude Tripod Leg ETX-90EC Latitude Balance Weight is recommended ifStandard Tripod Leg ETX-90EC Standard Tripod Leg ETX-125ECThe Moon Chapterz4 OBSERVINGOBJECTS IN SPACE PlanetsA few tips on photography with both ETX models OBSERVINGzPHOTOGRAPHY WITH BOTH ETX MODELS Astro Software/Cable Connector Kit Chapter 5 OPTIONAL ACCESSORIESPower ETX-90ECOPTIONAL ACCESSORIES location and a helicoid mechanism allows precise focusingOPTIONALz ACCESSORIES #1244 and #1247 Electric FocusersTroubleshooting Chapter 6 MAINTENANCEz AND SERVICINGGeneral Maintenance Storage and TransportCHAPTER Unable to see an image through the eyepiece MAINTENANCE AND SERVICINGTelescope pauses when changing slew direction Object appears in the viewfinder but not in the eyepieceSpecifications ETX-125EC Astro Telescope TELESCOPE SPECIFICATIONSSpecifications ETX-90EC Astro Telescope Northern Hemisphere Polar Appendix ATRACKING MOTOR SPEEDIndicator Light Key Light NoAppendix B HELPFUL CHARTS APPENDIX Precise Polar Alignment 24Appendix C PRECISE POLARz ALIGNMENT SETTING CIRCLESSetting Circles Appendix D ROADMAPzTO THE STARS The distances between the planets Appendix E YOU AND THE UNIVERSEThe distance from the Earth to the Moon The distance between starsMEADE LIMITED WARRANTY Meade Instruments Corporation 6001 OAK CANYON, IRVINE, CALIFORNIA 92618-5200 U.S.A

Appendix E: YOU AND THE UNIVERSE

The distance from the Earth to the Moon

The distances between the planets

The distance between stars

The distances between galaxies