The moon's ascending node (the point in the sky where its orbit crosses the ecliptic from south to north) is moving westward ...

The CDK20s have dual carbon-fiber truss design, with 3 cooling fans ejecting air from the back of the telescopes. The CDK20s cover a 52mm field of view without any field curvature, off-axis coma, or ...

Our four seasons are the by-product of the 23.5 degree tilt of the Earth's axis and during the course of a year we see the sun cycle between declination 23.5 degrees north and 23.5 degrees south ...