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.
Because planetary orbits are elliptical, not all oppositions are the same. In 2003, Mars made its closest approach to Earth in 50,000 years, an apparition that mesmerized sky watchers all over the world. The 2014 opposition of Mars is a much more run-of-the-mill opposition--not historic, but beautiful nonetheless.