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.
1 We're now coming into the home stretch of the last good apparition of Mars until 2016. Now blazing in the late-evening east-northeast sky like an eye-catching yellowish-orange star, Mars is less than six weeks away from its closest approach to Earth during this apparition.