Celestial mechanics Celestial mechanics Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, to produce ephemeris data. As an astronomical field of study, celestial mechanics includes the sub-fields of orbital mechanics, which deals with the launching and orbits artificial satellites, and lunar theory, a specialty which deals with the complications of the orbit of the Moon. Modern celestial mechanics tends to divide between five broad fields of study: All of the above fields overlap, but are sometimes
Luna moth fed walnut or hickory leaves versus white birch or American sweet gum. This suggests evolutionary and inducible adaptations to allow consumption of certain host plants. The Luna moth appeared on a first class United States postage stamp issued in June 1987. Although more than two dozen butterflies have been so honored, as of 2018 this is the only moth. Luna moth The Luna moth ("Actias luna") is a Nearctic moth in the family Saturniidae, subfamily Saturniinae, a group commonly known as giant silk moths. It has lime-green colored wings and a white body. The larvae (caterpillars) are also green. Typically,