Another error that such illustrations can bring says respect to the format of the represented planetary orbits. The information of that the orbits of the celestial bodies are not a perfect circle, but an ellipse, is true. However, in an attempt to illustrate this fact to the pupil, some books opt to showing drawings of exageradamente elliptical the planetary orbits (eccentric). But in reality the difference is not so great. The ellipse is so reasonable that to the simple ones to look at badly it would obtain distinguiz it of the circle. Although the eccentricity of the orbit of the Land, in form of ellipse, it confers perihelion (point where the planet meets next to the Sun) the 147 million kilometers and aphelion (point where the planet meets moved away from the Sun more) the 152 million kilometers, the difference is of only 3.3%.
The Sun reveals slightly bigger in the perihelion that in the aphelion, but this is only perceived by astronomers. (ASIMOV, 1979). Colorful nebulas and galaxies Another example of as some illustrations in didactic books can lead the errneas conceptions involve engravings of nebulas and galaxies. Normally misty and galaxies appear in such publications as possessing alive and berrantes colors. Some legends arrive at the point to relate definitive colors with specific chemical elements. However, the colors in nebulas and galaxies are only seen with the special equipment aid as spectroscopes and telescopes, such as of rays-x, gamma, infra-red ray, microwaves, etc, and radio telescopes, capable to observe the Universe in the band of the radio waves (SAGAN, 1996). A photo taken off by means of a telescope that operates in the band of the microwaves, for example, will show a universe in colors that never will be seen by the human eye to if using a normal telescope. Many times books include in its pages photographs of astros made with telescopes special and they are not given to the work to inform that the colors are not perceivable in visible light (LANGHI, 2006).