Okay kiddo, so imagine there's a planet called Venus up in space. And you know how when you draw a star, it has five points? Well, scientists have found out that when Venus moves around the sun (kind of like how the Earth goes around the sun), it creates a special pattern that looks like a five-pointed star.
They call it the "pentagram of Venus" because it looks like a five-pointed star, and it happens because Venus goes around the sun a certain way. This pattern can only be seen from Earth, and it's kind of rare because it only happens every 8 years!
So basically, the pentagram of Venus is a special pattern that happens in space because Venus moves around the sun in a specific way, and it looks like a five-pointed star. Cool, huh?