Phase angle (astronomy) less than 90° represent backscattering; values greater than 90° represent forward scattering. For some objects, such as the Moon (see lunar phases), Venus and Mercury the phase angle (as seen from the Earth) covers the full 0–180° range. The superior planets cover shorter ranges. For example, for Mars the maximum phase angle is about 45°. The brightness of an object is a function of the phase angle, which is generally smooth, except for the so-called opposition spike near 0°, which does not affect gas giants or bodies with pronounced atmospheres, and when the object becomes fainter as the angle approaches
Type 90 75 mm field gun and Battle of Okinawa, often deployed together with armored units. The Type 90 continued to be used as field artillery until the surrender of Japan. The Type 90 formed the basis for the Type 3 75 mm tank gun used in the Type 3 Ho-Ni III Gun tank and Type 3 Chi-Nu medium tank. Type 90 75 mm field gun The was a field gun used by the Imperial Japanese Army during the Second Sino-Japanese War, Soviet-Japanese Border Wars and World War II. The Type 90 designation was given to this gun as it was accepted in the year 2590