Controllers at the Jet Propulsion Laboratory will be using 12-in. ion thrusters to ease NASA's Dawn spacecraft into orbit around Vesta, a protoplanet in the asteroid belt between Mars and Jupiter that may have one of the oldest planetary surfaces in the Solar System. The probe has switched from radio navigation to the use of guide stars for the final leg of its journey, and has returned this first image of its approaching target, processed to show its true size—about 5 pixels at this 1.2-million-km range (inset)—against the large bright spot created with a long exposure time.
展开▼
