They're basically made up of debris left over from the origin of the solar system.

它们基本上是由太阳系起源时遗留下来的碎片组成的。

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], we'll have a much better solar system origin model," says NASA's Pamela Clark, author of "Dynamic Planet: Mercury in the Context of its Environment."

，我们将有一个更好的太阳系起源的模型，说：”美国宇航局的帕梅拉 克拉克，“动态行星：水星的环境”的作者。

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The Oort cloud is a vast belt of dust and ice that is believed to lie around one light year from the Sun and is the origin of many of the comets that pass through our solar system.

奥尔特云是一个由粉尘和冰组成的庞大云带，据信它距离太阳约一光年，许多穿越我们太阳系的彗星都来自那里。

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NASA's study of NEOs provides important clues to understanding the origin of our solar system.

ENGADGET: PSA: Asteroid 2012 DA14 will pass the Earth at 2:00pm ET Alt

Data from NEAR could help answer questions about the origin and composition of asteroids, comets and the solar system, according to the mission managers at the Applied Physics Laboratory in Laurel, Maryland.

CNN: NEAR and Eros

Moreover, Vesta may have survived intact from the solar system's origin, despite having been pummeled by impacts so violent that they sprayed the solar system with buckshot blasts of debris.

WSJ: Asteroid Vesta Gets a Close Study