Will We Still Recognize the Sky in 27,800 AD? - Sky: With Arcturus as our touchstone, we set off in a virtual time machine to visit the sky of the distant future.
Care to jump in my time machine for a look at what's ahead? I've chosen the year 27,800 AD because that's when precession of the Earth's axis will return Polaris to its seat near the North Celestial Pole. Precession, caused by torque produced by the Sun's and Moon's gravity on Earth's equatorial bulge, causes our spin axis to describe a circle in the sky with a period of about 26,000 years. In 3000 BC it pointed at Thuban in Draco; 12,000 years from now Vega will reign as polestar.
Telescopes competing with Celestron and MEDA:
2" ocular 90deg viewer !
|Mirror Coatings||94% Aluminum|
|Lens Coatings||Fully Multi-Coated|
|True Aperture (mm)||151|
|Primary Aperture (mm)||166|
|Primary Edge Thickness||12.5mm|
|Focal Length (mm)||1800|
|Secondary Obstruction (by diameter)||31%|
|Secondary Obstruction by Area||10%|
|Light Gathering (compared to next size down)||40%|
|OTA Length (Retract/Ext.)||17.5"|
|OTA Outer Diameter||7.5"|
|OTA Weight (with accessories)||14|
|Included Finder||9x50 Finder|
|Included Diagonal||2" Star Diagonal|
|Included Eyepieces||28 LET|
|Magnification w/ Included Eyepieces||64.3x|