Halsey's Mars Tattoo Halsey got a matching tattoo with her friend of Venus and Mars in 2015. "I got Mars because I met a guy on tour that I became really good friends with, and his birthday is on my half birthday, and I'm a Libra. So my ruling planet is Venus, and his ruling planet is Mars, which are also opposites," she said in an interview. Image Source: Getty / Jeff Kravitz