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.
UCSB Science Line. Mars is about 35 million miles from the earth -- and was closer on Aug 27. 2003 than at any time in the last several thousand years. Over two years, the distance varies from about 39 million to about 240 million miles. If you have a computer, you can download or purchase a program which will tell you down to the nearest few hundred kilometers for any time in last few thousand years (or into the future...).