QUESTION RESOUR 100% 1/2 > Tools Zoom Out Use the following additional information to answer questions 7 and 8 and numerical-response question 2. The robotic probe had a variety of instruments, including a device that used ground- penetrating radar and a spectral photometer (SPM), that were used to investigate Mars. Ground-penetrating radar can be used to examine subsurface structures and search for evidence of specific rock formations that would indicate the previous presence of water. This device has an antenna that has a length of 1.00 m, which is half the wavelength of the radar's EMR. An SPM can be used to identify the presence of particular substances. The SPM emits EMR over a broad range of the electromagnetic spectrum and detects those wavelengths that are reflected from the sample being examined. The photons that are not reflected cause electron transitions within the sample. The graph below shows SPM data for a particular sample and the deep dip, labelled CO2, indicates that carbon dioxide is present. Percentage of EMR Reflected as a Function of Wavelength 100 T 95 Percentage reflected 90 Co, 10 15 Wavelength (10 6 m)