Terra incognita refer to the hypothesized continent Terra Australis Incognita ("The unknown land of the South"), as seen in the Theatrum Orbis Terrarum map by Abraham Ortelius (1570). During the 19th century "terra incognita" disappeared from maps of the earth, since both the coastlines and the inner parts of the continents had been fully explored. But the bottoms of the seas remain mostly un-mapped, as do many other land surfaces in the solar system. The phrase is now also used metaphorically by various researchers to describe any unexplored subject or field of research. For more history of the terms, see Terra Australis,
Akaa Solar System Scale Model Model was built in 2017 by amateur astronomer Kari-Pekka Arola. A walking tour of Akaa Solar System Scale Model starts from the Sun and all the planets are located northbound from the Sun. The walking route goes through the center of Toijala and towards the port of Toijala, where the furthest dwarf planet in the scale model, Eris is located. All the planets and most notable dwarf planets are included in the scale model. The current location (140 AU) of Voyager 1 -spacecraft in relation to our solar system is also presented in the scale model (as the most distant