Roids are, for the most part anyway, they are just smaller bits of asteroids and comets.

在很大程度上，Roids 只是小行星和彗星的小碎片。

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The solar system also has two analogous classes of objects, smaller than planets—namely, asteroids and comets.

太阳系也有两类类似的物体，比行星还小——即小行星和彗星。

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Explore an asteroids and comets interactive.

探索一颗小行星和彗星们的相互作用。

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Colliding asteroids and comets would have delivered plenty of organic matter.

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Observatories around the world send their findings to the NASA-funded Minor Planet Center, which keeps a database of all known asteroids and comets in our solar system.

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The NASA Near Earth Objects (NEO) Program at the agency's headquarters in Washington, manages and funds the search, study, and monitoring of NEOs, or asteroids and comets, whose orbits periodically bring them close to the Earth.

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