Pentagram is not satanic. But for what I know there is an inverted pentagram and that is satanic (that's what they say). So make sure that you will do the correct pentagram. A star in a circle. The inverted pentagram has an inverted star. Try searching it in google for more info. Blessed be. :)
Yes, pentagram without a circle; pentacle inside a circle. It is a very old, extremely old, symbol; and means many things to many people.The ancient astronomers first "found" the pentacle by studying the sky at night. (Skies are very clear over deserts!)
It is the orbital path of the planet Venus. It takes around eight years, and forms a perfect (or near perfect) pentagram in the sky.
An reversed pentagram is not a satanic symbol. It is used to draw something to you. Point up on the star is protection, point down on the star is a calling of a specific energy. Ex:If you had an interview for a job you really wanted, you would wear a reversed pentagram the job interview to draw the energies for that job to you.