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.
The nearest that Mars has ever been to the Earth is 56 million km or about 34.8 million miles. On the opposite end of the scale, Mars and Earth can be a whopping 401 million km (249 million miles) apart when they are in opposition and both are at aphelion.