Venus is nearly identical in size to Earth

PatentYogi_The planet Venus is nearly identical in size to Earth, 121their radius' differ in size by only 201 miles, with Earth being the larger

Venus, Mars and Earth, three out of the four inner or ‘rocky’ planets of the Solar System, have a lot in common – a solid surface you could walk on, a comparable surface composition, an atmosphere and a weather system.

Here is a patent for a portable planetarium.

Patent Information
Publication number: US3287832 A
Patent Title: Portable planetarium
Publication date: 29 Nov 1966
Filing date: 4 Sep 1962
Priority date: 4 Sep 1962
Inventors: Baerg Herbert R
Original Assignee: California Inst Res Found

US3287832