Terrestrial planet from the original solar nebula. The Solar System has four terrestrial planets: Mercury, Venus, Earth, and Mars. Only one terrestrial planet, Earth, is known to have an active hydrosphere. During the formation of the Solar System, there were probably many more terrestrial planetesimals, but most merged with or were ejected by the four terrestrial planets. Dwarf planets, such as Ceres, Pluto and Eris, and small Solar System bodies are similar to terrestrial planets in the fact that they do have a solid surface, but are, on average, composed of more icy materials (Ceres, Pluto and Eris have densities of 2.17,
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