Geocentric Mercuryspheres in heliocentric system. Cross section through ecliptic plane. Steps of 2 days during a period of 360 days, from 1959-01-01. Blue dots are the positions of the Earth and the small dots of the inner circle show the orbit of Mercury, respectively. Data of the planetary orbits from NASA's Jet Propulsion Laboratory, Caltech. All calculations and graphical processing were done in R.