Breaking down of rocks and change in their chemical composition is called chemical weathering. It occurs when the unstable mineral present in the rocks react with water, gases in the air to produce some other minerals. The process of chemical weathering is more effective in a warm and humid climate as these conditions favor the chemical reactions to occur. Dry and cold climate slows down the chemical reactions and thereby, does not favor the process of chemical weathering.
<em>The Jan. 21</em> total lunar eclipse will be the last one until May 2021, and the last one visible from the United States until 2022; the most recent total lunar eclipse previous to this one appeared in July 2018.
