Psychology Glossary. Genotype. The total set of genes contained within an organisms cells. Organisms contain some genes that are expressed (you can consider the expressed to mean that the gene is active or being used) and some that are not. Regardless, all the genes an organism has are considered the genotype.
Mars' closest approach to the Earth is called opposition, and occurs roughly every 780 days.
Mars orbits the Sun at an average distance of 228 million km, which is about 1.5 times the distance of the Earth to the Sun. Earth and Mars can get as close as 54.6 million km apart, making Earth the closest planet to Mars. The size of Mars makes it the third largest terrestrial planet, after Earth and Venus.