The ring’s origin was initially connected to the lacking moon Dia, but Dia’s recovery in 2010 disproved this link. Among only two Martian moons, Phobos has actually been referred to as no more than a very small rock. NASA also notes that Phobos is over a collision course with Mars. https://collinfjjji.webbuzzfeed.com/35267921/moons-fundamentals-explained