Earth, as water planets located in so-called Goldilocks Zone of our solar system, has suffered series of mass extinction events during its entire history. In addition to the well-recognized space-originated mass extinction events (as K-T (K-Pg) extinction event that wiped out dinosaurs), Bruce Masse et al. proposed hypothetical catastrophic scenario that a comet collision occurred in Indian Ocean in 2,807 BC induced Mega-Tsunami  which might be the original event of “a great flood” in many legends. This lecture will focus on evaluating/rating potential risk of Space Hazards in comparison with different kinds of other natural hazards.