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
Nambu Type 90 Nambu Type 90 The Nambu Type 90 was a flare gun of Japanese origin and manufactured by Nambu. It was used by the Imperial Japanese Navy and came with two or three barrels. The Type 90 designation is from the last two digits of its year of adoption, which was 2590 (or 1930 AD) on the Japanese "Kōki" calendar. It first came with three barrels with just less than 6,000 were manufactured. The First Model (made in the early 1930s during peacetime) was highly polished and finished, while the Second Model (dating from the mid-1930s to the mid-1940s during wartime)