When it does, a spacecraft launched by NASA in 2016 is expected to be in position to provide a detailed examination of this rare close encounter. The tidal pull of Earth's gravity likely will cause measurable disturbances to the asteroid's surface and motion, changing its orbital path and rotational spin. The spacecraft is set to observe the asteroid's Earth flyby as it nears and ultimately catches up with Apophis. PLANETARY SCIENCE AND DEFENSELike other asteroids, Apophis is a relic of the early solar system. Close examination of Apophis could give planetary defense experts valuable information about the structure and other properties of asteroids.

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Persons: NASA's, Michael Nolan, It's, Nolan, it's, Steve Gorman, Will Dunham Organizations: NASA, APEX, NASA's Goddard Space, Empire, University of Arizona, SPACECRAFT'S SECOND, Planetary Science, Thomson Locations: Utah, Africa, Europe, Apophis, Los Angeles