Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession or nutation of an object's rotational axis. Prograde or direct motion is more normal motion in the same direction as the primary rotates. However, "retrograde" and "prograde" can also refer to an object other than the primary if so described. The direction of rotation is determined by an inertial frame of reference, such as distant fixed stars.
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession or nutation of an object's rotational axis. Prograde or direct motion is more normal motion in the same direction as the primary rotates. However, "retrograde" and "prograde" can also refer to an object other than the primary if so described. The direction of rotation is determined by an inertial frame of reference, such as distant fixed stars.
5.The sense organs — eyes, ears, tongue, skin, and nose — help to protect the body.
Key Concept: When fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. A fuel is a substance that provides energy as a result of a chemical change.
However, scientists are continually addressing these challenges, working to improve feasibility and reliability of renewable resources. Renewable resources include biomass energy (such as ethanol), hydropower, geothermal power, wind energy, and solar energy.
Many dams are built for more than one purpose; for example, water in a single reservoir can be used for fishing, to generate hydroelectric power, and to support an irrigation system. Water-control structures of this type are often designated multipurpose dams.
Antioxidants — such as vitamins C and E and carotenoids, which include beta-carotene, lycopene and lutein — help protect healthy cells from damage caused by free radicals.
Water in the early morning – between 6 a.m. and 10 a.m. Midday watering leads to wasteful evaporation, while nighttime watering causes droplets to cling to grass overnight, increasing the chance of lawn diseases.
Use a bucket instead of a continuous water flow from a hose. If you are using a hose, use one which has a spray handle that automatically shuts off the nozzle as you leave it. According to the Department of Environment, Maryland, USA, a 100 gallon car wash reduces to 30 gallons in such an arrangement.
We refrigerate food to keep bacteria, yeasts, and molds from the favorable temperature they need to grow. The moisture-control available in many refrigerators also helps slow the deterioration of foods, so that two of the three favorable situations for microorganism growth are eliminated.
