Answer:
The orbit of the Earth
Explanation:
It is widely speculated that orbital mechanics were responsible for the period of lushness that the Sahara desert and Northern Africa lived only 6000 years ago. Due to the changes in the Earth's orbit around the Sun, it is thought that the monsoon effect (season variations in wind patterns that produce a heavy rainy season) was more pronounced across the northern latitudes and resulted in the Sahara being much wetter than it is today.
<span>Observations show that all galaxies tend to move away from earth, and that more distant galaxies move away from earth at faster velocities than do galaxies closer to the earth. these observations imply that</span> galaxies with high speeds as measured from Earth are moving away from Earth and are farther from Earth than galaxies with lower speeds.