NASAのインスタグラム(nasa) - 6月13日 02時21分

Scientists used Earth-based radar to produce these sharp views of the asteroid designated “2014 HQ124" on June 8, 2014. 2014 HQ124 is what scientists call a "contact binary": an asteroid that consists of two lobes that are in contact and that could have once been separate objects. About one in six asteroids in the near-Earth population has this type of elongated, "peanut" shape.

The asteroid is about 1,300 feet (400 meters) long and about half as wide. The radar images reveal a wealth of interesting features, including a large depression or concavity on the larger lobe as well as two blocky, sharp-edged features at the bottom on the radar echo. Scientists suspect that some of the bright features that persist from frame to frame could be surface boulders. The 21 radar images were taken over a span of four hours. During that interval, the asteroid rotated a few degrees per frame, suggesting its rotation period is slightly less than 24 hours.

At its closest approach to Earth on June 8, the asteroid came within 776,000 miles (1.25 million kilometers), or slightly more than three times the distance to the moon. Scientists began radar observations of 2014 HQ124 shortly after the closest approach, when the asteroid was between about 864,000 miles (1.39 million kilometers) and 902,000 miles (1.45 million kilometers) from Earth.

Image Credit: NASA/JPL-Caltech/Arecibo Observatory/USRA/NSF
#dsn #nasa #space #asteroid #asteroidwatch #radar #neo #nearearthobject

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