... in front of visual /Nikon 28-80G the group (aspheric surface), at present tests, the imagery is good, not obvious chromatic ... 1. The Inner Planets. Spheres of Rock . a) Mercury b) Venus c) Earth d) Mars . 2. The Outer Planets. The Gas Giants . ...
... Thor's Helmet is the bubble formed by the stellar wind, with the surface of the bubble composed of the galactic gas and dust piling up as the bubble's surface expands into space, pushed by the stellar wind. ...
... have six elements in four groups, and all air-to-glass surfaces are treated with broadband coatings that transmit 99.98 ... well also for variable star observing, solar observing, eclipses, Mercury and Venus transits of the Sun, and lunar occultation ...