Unraveling the mystery of the solar system

摘要

Our solar system is thought to have formed from a thick cloud of gas and dust left behind from an ancient exploding star.Then,through a process of mutual gravitational attraction among particles,the cloud began to condense and collapse,eventually giving birth to a new protostar-our Sun.The enormous swirling disk of gas and dust,called the solar nebula,encircled our Sun during this early period and,over millions of years,condensed to form planets,moons,asteroids,and comets.The elements for the inner "rocky"planets,Mercury,Venus,Earth,and Mars,were forged in the hottest regions of the nebula,closest to the newborn Sun.The cold gas giant planets,Jupiter,Saturn,Uranus,and Neptune,were formed in the outer regions,where it was cold enough for ice to be stable.