Assalamu 'alaikum, I looked up the meaning of 'retrograde motion' and I found that it's actually just an illusion, that it seems as though planet Mars goes in the opposite direction, but then continues in the right direction again. The reason for this illusion is that Earth's orbit is not in the same plane as Mars. So, although it seems that Mars is changing direction, it's actually just continuing in the same path as normal. I am a Muslim, and when I read this, I thought it's a miracle. I was going to share this miracle with my non-Muslim friends in da'wah. However, we should always check the truth of something and not just follow blindly. It would have been so embarassing to share this with my non-Muslim friends, only to find out that what I thought was true turned out to be false. You can find out more about retrograde motion by looking for nasa retrograde motion on google. Jazakumullahu khairan kathira. Wassalam, Fauzan