The Differences Between Terrestrial and Celestial Telescopes

What is a "Terrestrial Telescope"? A Telescope that can be used, or is designed primarily, for land-based viewing.

Terrestrial Telescopes are usually Refractors that offer erect upright viewing through a system of lenses and mirrors. 

Typically, Refractor Telescopes will come with Erecting Prisms or Diagonals - which turn the image right side-up - so that the image orientation will be as you see it with the naked eye.

Terrestrial Telescopes typically deliver higher magnification specifications, and lower aperture specifications. With a Terrestrial Telescope, magnification matters.

Example: National Geographic 70mm CF700SM Refractor Telescope

An Ideal Terrestrial Telescope: The Spotting Scope

When it comes to land-based viewing, Spotting Scopes are typically the best choice - due to their zoom capabilities, size/portability, and durability. Spotting Scopes are designed primarily for land-based viewing. 

Example: Athlon Optics Ares G2 15-45x60mm UHD Spotting Scope

What is a "Celestial Astronomy Telescope"? A Telescope that is designed for viewing distant stars and planets.

Astronomy Telescopes include Refractors, Reflectors, and Catadioptric Telescopes. Astronomy telescope apertures are typically larger, as a larger aperture increases the telescopes light-gathering capabilities. Increased light-gathering allows for viewing dimly lit night sky objects. 

The most important parameter in Astronomy telescopes is light gathering power, hence the larger aperture. With a Celestial Telescope, aperture matters.

Astronomy telescopes utilize a system of mirrors that deliver an inverted, upside down image.

As is mentioned above regarding Terrestrial Telescopes, inverted images on Celestial Telescopes can also be reversed by placing an erecting prism between the telescope and the eyepiece. 

Example: Explore Scientific FirstLight 80mm Refractor Telescope	Example: Explore Scientific FirstLight 114mm Newtonian Reflector Telescope
Example: Explore Scientific 10-inch Dobsonian Reflector Telescope	Example: Explore Scientific FirstLight 152mm Mak-Cassegrain Telescope