A multispectral selective reflection Lidar system generates alternating pulses of at least two wavelengths and senses returns for determining the presence of a predetermined material absorbing and reradiating one wavelength as selective reflections, but not the other. A detector can readily determine the presence or absence or an absorbing and reradiating return. The system is for preferred use as an orbiter sensor about a planetary body, such as a Jupiter moon, for determining the presence of organic material and for the relay of information back to earth.
                                                         Keywords:  lidar
            
      
                                                                                                     International Class:  G01J5/02,  G01J3/45,  G01N21/00