24 November 2006
Vol 314, Issue 5803

About The Cover

Cover image expansion

COVER A radar-derived model of Alpha, the larger half of the binary near-Earth asteroid (66391) 1999 KW4. Alpha is an unconsolidated aggregate 1.5 kilometers in diameter; its effective slope ranges from zero (blue) to 70° (red). Its rapid 2.8-hour rotation induces material to flow (arrowheads) from both the northern and southern hemispheres toward the equator. See pages 1276 and 1280. Image: NASA/JPL