地质基础知识回顾 地球：成因与结构 地质年代 板块构造理论 地质构造 岩石类型地质基础知识回顾 地球：成因与结构 地质年代 板块构造理论 地质构造 岩石类型地质基础知识回顾Looking Back In Time A look back in time. WMAP, in the present era, looks back to the first light to break free in the Universe, the afterglow of the Big Bang (far left) that emerged 380,000 years after the Big Bang. This light, seen today, has taken over 13 billion years to reach us. During that time, giant clouds of gas in the early Universe (left side) condensed under the force of gravity to form the first stars (200 million years after the Big Bang). Then, galaxies and galaxy clusters formed into the vast structure we see today (right side). The temperature fluctuations seen today correspond to the seeds that grew to become galaxies.地质基础知识回顾地球：成因与结构地质基础知识回顾地球：成因与结构地球形成后不久，一颗小行星与之发生撞击产生的碎屑形成围绕地球的碎屑环由碎屑环形成了月球地质基础知识回顾地球：成因与结构地质基础知识回顾地球：成因与结构地质基础知识回顾地球：成因与结构地质基础知识回顾地球：成因与结构地质基础知识回顾地球：成因与结构地质基础知识回顾地球：成因与结构地球均衡原理