Each month, we share a Star Gazing Guide presented and organized by The Great Orbax, a science communicator from the University of Guelph's department of physics and local science education advocate.
Greetings Star Gazers!
Orbax here.
I’m a Science Communicator from the Department of Physics at the University of Guelph, and I’m here to fill you in on what our February night skies hold for the Astro-curious out there, young and old.
Unfortunately, this month’s article comes with a warning… Mars is in retrograde!
Before we get carried away, let me explain what retrograde motion actually is.
Retrograde just means backwards. In astronomy, terms it refers to motion that is opposite the direction that something normally travels. And when we mention that a planet such as Mars is in retrograde, it just means that from our view here on Earth, it looks like Mars is travelling backwards across the sky compared to how it usually travels.
I suppose it would be quite shocking to our ancestors if they suddenly saw a planet reverse its direction in its travels, and that is likely why it’s become synonymous with ill fortune. But what makes a planet change its direction like that? Why would it suddenly start moving backwards?
Well, here’s the thing, it’s just an illusion that occurs from our point of view here on Earth. Mars is further from the sun than we are, which means that we are actually moving faster in our orbit than Mars is. Think of it like a circular racetrack. We’re in a race with Mars, and we’ve got the faster inside track! As we approach Mars, it is moving forward but as we get closer it appears to slow down from our perspective and eventually looks like it’s moving backwards, even though in reality it is still continuing its motion along its orbital path.
Eventually, we get far enough away from Mars that it will return to its normal motion, and this year that occurs on Feb 23rd. Mars enters retrograde motion about every two years, but every planet in the solar system enters through phases of this apparent retrograde motion. If you’re like me, it might take some time to wrap your head around this phenomena, but why don’t you head over to this month’s Star Gazing Guide where you can see the video version of this explanation. I promise, it will become very clear.
Oh, and just so you know, there is no reason to fear periods of retrograde motion. In fact, there’s no scientific evidence that retrograde motion has any effect on you whatsoever.
I hope you enjoy this month’s Star Gazing Guide. If you want to learn more, check out the February Star Gazing Guide video on the Guelph Physics YouTube channel. Not only is Star Gazing a great way to learn about space, planets and the stars, but it’s also a great way to spend time with other curious minds.
Until next month, I wish you clear skies and I hope you take some time … to look up.
