3.8.2 Greatest hits from previous weeks

3.8.2.1 Make a beautiful Moiré effect

http://mathematica.stackexchange.com/questions/112998/make-a-beautiful-moir%c3%a9-effect

 
How do I make the following Moiré pattern? 
 
 
 
I tried: 
 
A = Plot[Table[n, {n, 1, 30}], {x, 0, 31}, 
GridLines -> {Table[n, {n, 1, 30}], None}, 
GridLinesStyle -> AbsoluteThickness[1.2],  ...
 

- asked by vito (23 votes), answered by gpap (34 votes)

3.8.2.2 Beautiful dance of the Earth and Venus around the sun

http://mathematica.stackexchange.com/questions/115358/beautiful-dance-of-the-earth-and-venus-around-the-sun

 
I have seen very nice dynamic graphics created by users of Ma. I would like to get help whether the following graphics can be created using Ma. I was not able to create the dynamic picture here.  ...
 

- asked by ramesh (11 votes), answered by ubpdqn (6 votes)