Deserts are the regions that cover little or no vegetation and there is no rainfall. Deserts are very hot in the day time and cold during the night time. It is because during the day time the sun heats up the sand, as a result of which the sand becomes very hot increasing the temperature. This increasing temperature in the desert is also because of the absence of rainfall and vegetation cover.
Thus, the desert area is rich in heat energy during the day time. But at night, the sand releases its heat energy back into the atmosphere through infrared radiation because the dry air cannot hold the heat anymore. This release of the heat energy allows the sands to cool, thereby dropping the temperature.
DUE TO GRAVITATIONAL COLLAPSE SOLAR SYSTEM IS FORMED , ORBITS ARE CURVED TRAJECTORIES AND SIZE AND COMPOSTION OF PLANET ARE VERY UNIQUE AND COMPOSED OF ROCKS AND METALS and evolution of solar system has began 4.5 billion years ago,due to gravitational collapse of a small particle from a giant cloud.
