Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the importance of protecting our world for future generations [1]. To provide the protection of our planet, we should explain Earth’s environmental challenges to the best of our knowledge in frames of contemporary Geophysics. This paper gives a short overview of the developed Hypersphere World-Universe Model (WUM) and pay particular attention to the principal role of Dark Matter (DM) in the Earth’s life. In this manuscript, we discuss different aspects of the Earth: a condition of Early Earth before the Beginning of life on It; Internal Structure; "The 660-km Boundary" that we named Geoplasma; Random Variations of Earth’s Rotational Speed on a daily basis; Origin of Moon; Expanding Earth; Internal Heating; Faint Young Sun paradox; Geocorona and Planetary Coronas; High-Energy Atmospheric Physics. WUM proposed principally different way to solve the problems of Internal Heating, Origin of the Moon, and Faint Young Sun paradox based on DM core of the Earth. The Model revealed the fact that the Sun Activity causes the Geoplasma Activity and, as a consequence, Random Variations of Earth’s Rotational Speed by the varying Sun’s magnetic field.