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 Opposition of Mars. March 28, 2014: By the time you finish reading this story, you'll be about 1,000 km closer to the planet Mars. Earth and Mars are converging for a close encounter. As March gives way to April, the distance between the two planets is shrinking by about 300 km every minute. When the convergence ends in mid-April, the gulf between Earth and Mars will have narrowed to only 92 million km--a small number on the vast scale of the solar system.