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.
On average, the distance to Mars from Earth is 140 million miles (225 million km). In their race around the sun, Earth on its inside track laps Mars every 26 months. This close approach provides an opportunity â a launch window â to send spacecraft to the red planet.