The moon, one of the nine planets, Navagraha.
Another name of Chandra is Soma.
Chandra had an adultery with Tara.
Read about Chandra here
http://www.sushmajee.com/shani/1-kathaa-1-19/2-chandramaa.htm
http://utkarshspeak.blogspot.com/2010/10/waxing-and-waning-of-moon.html