Meade ETX-90PE instruction manual Appendix Ebasic Astronomy, AutoStar Glossary, Moon

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Fig. 57: The Moon. Note the deep shadows in the craters.

APPENDIX E:BASIC ASTRONOMY

In the early 17th century Italian Scientist Galileo, using a telescope smaller than your ETX, turned it skyward instead of looking at the distant trees and mountains. What he saw and what he realized about what he saw, has forever changed the way mankind thinks about the universe. Imagine what it must have been like being the first human to see moons revolve around the planet Jupiter or to see the changing phases of Venus! Because of his observations, Galileo correctly realized Earth's movement and position around the Sun and in doing so, gave birth to modern astronomy.Yet Galileo's telescope was so crude, he could not clearly make out the rings of Saturn.

Galileo's discoveries laid the foundation for understanding the motion and nature of the planets, stars and galaxies. Building on his foundation, Henrietta Leavitt determined how to measure the distance to stars, Edwin Hubble gave us a glimpse into the possible origin of the universe, Albert Einstein unraveled the crucial relationship of time and light and 21st-century astronomers are currently discovering planets around stars outside our solar system. Almost daily, using sophisticated successors to Galileo's telescope, such as the Hubble Space Telescope and the Chandra X-Ray Telescope, more and more mysteries of the universe are being probed and understood. We are living in the golden age of astronomy.

Unlike other sciences, astronomy welcomes contributions from amateurs. Much of the knowledge we have on subjects such as comets, meteor showers, double and variable stars, the Moon and our solar system comes from observations made by amateur astronomers. So as you look through your Meade ETX telescope, keep in mind Galileo. To him, a telescope was not merely a machine made of glass and metal, but something far more—a window of incredible discovery.

AutoStar Glossary

Be sure to make use of AutoStar’s Glossary feature. The Glossary menu provides an alphabetical listing of definitions and descriptions of common astronomical terms. Access directly through the Glossary menu or through hypertext words embedded in AutoStar. See GLOSSARY MENU, page 24, for more information.

The Moon

The Moon is, on average, a distance of 239,000 miles (380,000km) from Earth and is best observed during its crescent or half phase when Sunlight strikes the Moon’s surface at an angle. It casts shadows and adds a sense of depth to the view (Fig. 57). No shadows are seen during a full Moon, causing the overly bright Moon to appear flat and rather uninteresting through the telescope. Be sure to use a neutral Moon filter when observing the Moon. Not only does it protect your eyes from the bright glare of the Moon, but it also helps enhance contrast, providing a more dramatic image.

Using your ETX model, brilliant detail can be observed on the Moon, including hundreds of lunar craters and maria, described below.

Craters are round meteor impact sites covering most of the Moon’s surface. With no atmosphere on the Moon, no weather conditions exist, so the only erosive force is meteor strikes. Under these conditions, lunar craters can last for millions of years.

Maria (plural for mare, seas) are smooth, dark areas scattered across the lunar surface. These areas are ancient impact basins that were filled with lava from the interior of the Moon by the depth and force of the meteor or comet impact.

12 Apollo astronauts left their bootprints on the Moon in the late 1960’s and early 1970’s. However, no telescope on Earth can see these footprints or any other artifacts. In fact, the smallest lunar features that may be seen with the largest telescope on Earth are about one-half mile across.

Note: Except during its early or late crescent phases, the Moon can be an exceptionally bright object to view through the telescope. To reduce the brightness and glare, use the #905 Variable Polarizing Filter (see the MEADE GENERAL CATALOG for more information).

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Contents ETX Premier Edition Telescope Series Page Contents QUICK-START Guide Enter Key Scroll Scroll Up Down B and Fig Telescope FeaturesTelescope Controls Ascension and Declination setting circles? SeeSmartfinder SmartFinder? See AligningComputer Control Panel see Fig DefinitionsAlt/Az, Right Ascension, Tour the Cosmos with Just the Push of a Button Autostar FeaturesAutoStar to the topmost screen Select Item Object About changing slew ETX TipsParts Listing How to Assemble Your Telescope and TripodGetting Started Aligning SmartFinder Using SmartFinderChoosing an Eyepiece Too Much Power?Observing Observing Using AutoStar Arrow KeysObserving by Moving the Telescope Manually Terrestrial ObservingAstronomical Observing Slew SpeedsObserve the Moon To Track an Object AutomaticallyHow to perform the Automatic Alignment procedure Initializing AutoStar for the First TimeAutomatic Alignment Which One’s the Alignment Star? Observe a Star using the Automatic Tracking FeatureGo To Saturn Using the Guided TourAutostar Autostar OperationAutoStar Navigation Exercise To Calculate Sunset timeLook into the Future Entering data into AutoStarSelect Item Object Autostars MenusObject Menu options include Object MenuUse the Object menu to select an object from the database Observing Satellites? SeeGlossary Menu Event MenuUse the Event menu Use the Glossary menuTips Utilities MenuSetup Menu Periodic Error Correction? See Tip Shift Adding and editing sites? SeeAdding Observing Sites Advanced Autostar OperationTo Add a Site to the user-defined site list To Edit a SiteUsing AutoStar to Find Objects Not in the Database Observing SatellitesTo GO to a user-entered object How to Create Your Own Guided Tour What you will needTour Modes Command Line Comment LineWriting a Tour Moon Downloading Tours LandmarksTo Add a landmark to the database IdentifyTo Select a landmark from the database To perform a Landmark SurveyAdvanced Alt/Az Alignment Displayed information ExampleTwo-Star Alt/Az Alignment and Easy Align Smart Drive Training Periodic Error Correction One-Star Alt/Az AlignmentPEC Train Menu Option PEC Update Menu Option BrowsePEC Erase Menu Option Photography with a 35mm Camera PhotographyPhotography with a Digital Camera Few Tips on PhotographyDeep Sky Imager Photography with Meade’s AutoStar Suite#505 Cable Connector Kit With Meade AstroFinder Optional Accessories#932 45 Erecting Prism Maintenance Troubleshooting Storage and TransportInspecting the Optics Telescope does not track a celestial object Meade Customer ServiceSpecifications Specifications ETX-90PE Astro TelescopeSpecifications ETX-105PE Astro Telescope Specifications ETX-125PE Astro Telescope Telescope dimensions 43cm x 25cm x 20cm 17 x 10 xAutoStar Dimensions AutoStar SpecificationsCelestial Coordinates Equatorial AlignmentLoosen control latch Set latitude Locating Polaris Latitude Chart for Major Cities of the World Appendix B Latitude ChartCity State/Prov./Country Latitude City Country LatitudeFurther Study Appendix C Training the DriveTo replace the battery Appendix Dchanging the LNT Module BatteryAppendix Ebasic Astronomy AutoStar GlossaryMoon Deep-Sky Objects PlanetsPage Meade Limited Warranty

ETX-90PE specifications

The Meade ETX-90PE is a well-regarded telescope that combines portability and performance, making it a popular choice among both amateur astronomers and seasoned stargazers. Its compact design and advanced features make it an ideal instrument for those who seek to explore the night sky with ease.

At the heart of the ETX-90PE is its Maksutov-Cassegrain optical design, which utilizes a spherical primary mirror and a corrector lens to deliver exceptional image quality. With a focal length of 1250mm and a 90mm aperture, it strikes a balance between light-gathering ability and magnification, allowing users to observe celestial objects such as planets, star clusters, and distant galaxies in remarkable detail. The telescope's focal ratio of f/13.9 provides crisp and sharp views, making it particularly well-suited for planetary observation.

One of the standout features of the ETX-90PE is its Electronic Control System (ECS), which allows for easy and intuitive operation. The telescope is equipped with a built-in AutoStar Computerized GoTo mount, enabling users to locate and track over 30,000 celestial objects with just a few simple commands. With automatic alignment features, even beginners can get started quickly, making the wonders of the universe accessible to everyone.

Portability is a key characteristic of the Meade ETX-90PE. Weighing in at a mere 12.5 pounds, it can be easily transported to dark sky locations. Its compact design not only translates to ease of transport but also means it can be stored conveniently when not in use. The included sturdy aluminum tripod provides stable support, even during extended observation sessions.

The ETX-90PE further enhances the user experience with its high-quality accessories. It comes with a set of eyepieces, including a 26mm Super Plössl and a 9.7mm Plössl, allowing for various magnifications to suit different observing preferences. The telescope also features a built-in flip mirror, allowing for easier viewing through both the eyepiece and a camera, making astrophotography more accessible.

Additionally, the ETX-90PE is designed with user comfort in mind. The telescope offers adjustable slow-motion controls for fine-tuning views and an optical finder scope to help locate objects before zooming in. With robust construction, excellent optics, and a range of advanced features, the Meade ETX-90PE stands out as a versatile, high-quality telescope for both casual observers and serious astronomers alike. Its combination of technology and user-friendly functions makes it an enduring favorite for anyone looking to embark on a journey through the cosmos.