Comets, often described as "dirty snowballs" or "icy mudballs," are primitive remnants from the formation of our solar system roughly 4.6 billion years ago. While asteroid strikes are more frequent, a comet impact carries unique risks due to its immense velocity and volatile composition of frozen gases, rock, and dust. The Mechanics of an Impact
A comet’s potential for destruction is defined by its mass and speed. Comet Impact
: Upon impact, comets can create massive vapor plumes that rise thousands of kilometers into the atmosphere, depositing debris that increases opacity and drastically lowers global temperatures. Historical and Theoretical Impacts Comets, often described as "dirty snowballs" or "icy
Scientists have identified several points in history where comet impacts may have reshaped Earth's climate and human society: : Upon impact, comets can create massive vapor
: While asteroids typically hit at about 20 km/s, comets can reach speeds up to 71 km/s. Because kinetic energy scales with the square of velocity, a comet can deliver more than 100 times the energy of a similarly sized asteroid.
: Long-period comets can be pulled apart by the sun's gravity before reaching Earth, potentially hitting as a "cluster" of fragments rather than a single body.
What Is a Comet? | NASA Space Place – NASA Science for Kids
