If you wonder where is the dark shadow cast by Cabeus, this image explains:
The image was not taken by an optical telescope. It is a radar-derived image in a search for water-ice in permanently shadowed areas around the lunar south pole (SP). The radar beam was transmitted in April 2005 by Arecibo Observatory in Puerto Rico at 13 cm wavelength (2380 MHz). The radar echo was received by the 100-m radio telescope in Green Bank, West Virginia. No clear evidence of water-ice was found, although a small number of areas with anomalous radar properties need further investigation. (Source: NAIC / Cornell University)
發表於 2009-10-7 02:17:06
