Astrology in retrograde

By Phil Plait | October 3, 2008 10:30 am

I was called by MSNBC reporter Helen Popkin yesterday because she was doing an article on astrology. And she stumped me with a simple question: "Have you heard," she asked "about the idea that electronics tend to fail when Mercury is in retrograde?"

Uh. What?

I hadn’t heard of this little piece of nonsense, but according to Ms. Popkin, sure enough, some astrologers say that technology tends to fail more when Mercury is in retrograde — that is, when its apparent motion in the sky switches from an eastward direction to westward. Since, astrologically, Mercury controls communication and technology, when it’s in retrograde things get screwed up. That’s why Hubble is malfunctioning, and why the LHC is having woes.

Yeeeeeeah. Oooooookay.

So for the next half hour we chatted technology, we chatted Mercury, we chatted astrology. You can guess how I feel about all this astrology stuff.

Or you can read about it. The article she wrote is online. It’s a fluffy humor piece, not really meant to sway people either way. I smiled a lot while reading it, even though astrologers makes me want to stick my head in the microwave.

So, does Mercury have anything to do with tech bugs here on Earth? I’m guessing… no. Duh. I wonder if these astrologers ever set up a study looking at various technology failures, correlating them with Mercury’s apparent motion. They’d also need to do control studies where tech has been very successful at the same time… not to mention when tech has failed when Mercury is prograde (the opposite direction of retrograde), and when tech is successful then, too.

Yeah. I’m sure they have. Astrologers are all about the accurate science.

So you know what’s next. Wait for it… wait for it…

The stupid, it burns

CATEGORIZED UNDER: Antiscience, Astronomy, Debunking, Humor

Comments (77)

  1. Scientific Method for the Stupid: Find one or two instances that support your view. IGNORE everything else…

    I’m sure that a 0.000001% correlation is strong enough for them Dr Plait.

  2. Pete G

    Haha. On the topic of this sort of nonsense, I’ve heard this email has been floating around:

    “Coming October 17, 2008 the sun will rise continuously for 36 hrs

    (1.5days). During this time the US countries will be dark for 1.5 days.

    It will convert 3 days into 2 big days. It will happen once in 2400 yrs .

    We’re very lucky to see this. Forward it to all ur friends. ”

    Yes, it burns.

  3. Scott

    perhaps there’s a correlation between mercury’s position and how the solar flares leave the sun to burn out our electronics…

  4. I think this just about says it all:

  5. On the bright side, at least Astrology proposes valid, testable hypotheses…

  6. Yoo

    It’s technically true that electronics tend to fail when Mercury is in retrograde. It’s just that electronics also tend to fail when Mercury is not in retrograde …

  7. Vernon Balbert

    Then why hasn’t my car failed? My computer? My blood glucose meter? My cell phone? The airplanes I flew in last Monday? My debit card? The scanner at the grocery store? How come all the satellites that control nearly all communications haven’t failed?

  8. When I first read the title of this post I assumed that it was going to center on someone not knowing what retrograde motion was and freaking out,

    “Oh my god, Mercury is going backwards! This must be a preface to the coming of Nemesis and Niburi and two suns in the sky and it’s not even 2012 yet! Yikes!”

    Given that my assumption was wrong, the actual post was really kind of a relief.

  9. Fizzle

    I accidentally put my cellphone through a washing machine, however that happened a month ago… Wait a minute, A MONTH AGO!!! THE LHC IS MESSING UP THE PLANETS ORBITS!!! WERE ALL GOING TO DIE!!!!

  10. ND

    Your head? You mean stik THEIR head in the microwave. In which case the cartoon now makes much more sense.

  11. rbp

    If astrologers make you want to stick your head in the microwave, you should do it now, while Mercury is in retrograde!

    So, you know, you’re sure not to be harmed… Retrograde…

  12. All right everyone… calm down.

    First off, astrology is NOT about absolutes… and mercury Retrograde periods are only thought to make it MORE LIKELY that mechanical breakdowns will occur, not that they absolutely WILL. I’m sure someone with the time and energy could do the studies you request and get back to you. In the meantime, think POTENTIAL not FACT.

    Mercury Retrogrades are also times when you want to avoid making long term decisions or sign contracts, especially complex ones. Communication breakdowns on a personal level are all possible. POSSIBLE not FOR SURE.

    And, just so you know, not all astrologers believe the Mercury Retrograde times are all bad. They are ideal for reviewing work or personal issues.

    I think I can safely speak for most professional, ethical astrologers (not the 900 number crowd) that YES we are a science, we have a HISTORY whether you want to believe it or not, and we don’t live our lives according to the stars. We use what the stars tell us for timing, perhaps to understand a person or situation, but NOT AS AN ABSOLUTE PREDICTIVE TOOL.

    Anyone who tells you otherwise is lying to you.


  13. madge

    This is a new one on me. So three or four times a year Mercury screws with technology. It makes SO MUCH SENSE! That is almost exactly the frequency with which electronic gizmos in my house go on the fritz! (madge runs off to check her insurance policy to see if she is covered against acts of woo)

  14. rob

    i truly believe that retrograde mercury has an effect of breaking things. just look at how many people seem to have their critical thinking skills impaired just as mercury goes retro. coincidence? i think not!

  15. My tarot cards say you’re right Phil.

  16. @Susan. Astrology is no better than random guesses though. That there is an entire industry based off this nonsense is a CON. Straight and simple. Sure, you use some social engineering to sound more plausible to the victim who you are taking money from, but even the “probability” correlation isn’t there. Not in the slightest!

    And to call yourself a “science” because you have a “history”? What sort of claim is that? Do you even know the definition of those two words? If you fail to even predict a possibility on the same level as wild guesses, what makes your “field” more valid than your filed simply not existing?

  17. hale_bopp

    Now you are telling me I have to worry about my computer? Let’s see, my computer was “born” under Pisces…what’s its horoscope for today?

  18. bjn

    Ethical astrologers is an oxymoron.

    Yes, chemistry came from alchemy, and astrologers did a good job of documenting the motions of the stars. But alchemy and astronomy are hokum wrapped around a tiny core of real understanding.

    Astrology is most certainly not a science and, Sue, if you think you’re a scientist you don’t have a clue as to what a scientist does.

  19. bjn

    That should be “alchemy and astrology are hokum”. Note to self: proof carefully before hitting submit.

  20. Pete G

    I don’t see how having a history makes Astrology a science. Does the thousands of years of history of most religions make them a science? What about the countless ancient myths?

    Saying events like mercury going into retrograde will make certain things potentially happen makes it less of a science, as electronics and communications always have a potential to break down. Astrology would be correct if electronics DID fail when mercury was in retrograde and not if they only had the ‘potential’ to.
    As you put it, potential, not fact. That definition makes Astrology unscientific.

  21. Jose

    Why, my computer’s working just fi

  22. Ted S.

    Actually, spacecraft in low earth orbit are (slightly) more likely to suffer electronic faults during local sunrise and sunset. The flux of charged particles from the sun is greater at those positions.

  23. Ray

    Susan owes me a keyboard. “Ethical” and “Astrologer” in the same sentence made me spew Coke all over it.

  24. Hey, now, Susan is right, Astrology is technically a valid scientific hypothesis, in the sense that it makes predictions based on a theoretical framework, and those predictions are then open to scrutiny.

    What Susan neglected to point out, however, is that Astrology isn’t just a valid scientific hypothesis, it’s also a disproven one.

  25. @Pete G

    “Saying events like mercury going into retrograde will make certain things potentially happen makes it less of a science”

    I completely disagree. You could *easily* apply statistical methods to test this hypothesis. That fact no one has because it is, frankly, ridiculous, doesn’t make astrology an invalid hypothesis. A ridiculous one, yes, but not invalid.

  26. “YES we are a science”

    Without studies, no you’re not. Sorry, you’re just not.

  27. Sam

    Forget all this astrology stuff… The article uses “nonplussed” incorrectly!

    And yes, I’m aware of the new definition; that is, pretty much the opposite of the correct definition, but I reject it. 😉

  28. I hear about people whining about Mercury being in retrograde all of the time — anytime something bad happens they are like “Oh, Mercury is in retrograde, no wonder!” I ask them what they would blame it on if Mercury wasn’t in retrograde and they can’t answer.

  29. TheSkier

    Someone correct me if I’m wrong, but I understood only planets beyond Earth undergo retrograde motion. I’m trying to convince myself of this matter, but have class to attend.

  30. Oh, c’mon, anyone who’s read Jim Butcher’s THE DRESDEN FILES books knows it’s WIZARDS that cause electronic/high tech problems.



  31. Susan Morgan Says: “YES we are a science, we use what the stars tell us for timing, perhaps to understand a person or situation, but NOT AS AN ABSOLUTE PREDICTIVE TOOL.”

    Sorry. Science is an absolute predictive tool. That’s the whole point. If you can’t, then you’re not.

    – Jack

  32. Scott Says: “perhaps there’s a correlation between mercury’s position and how the solar flares leave the sun to burn out our electronics…”

    I’m not sure if this was a joke or not, but just FYI:

    Mercury’s retrograde motion is artificial. The planet really doesn’t stop and back up. This apparent motion is an illusion caused by the way sightlines work on two bodies orbiting the same center (the sun).

    – Jack

  33. Davidlpf

    I have a prediction, that is not the last time we see that cartoon.

  34. DG


    here’s a cool little applet I found real quick. It shows the motion from Earth to Venus and Mars:

  35. drksky

    By your reasoning, Susan, I could say that I could POSSIBLY get run over by a bus when I walk to the corner store tomorrow because Mercury is in retrograde. Sure, it’s possible, but then it’s also possible at ANY OTHER TIME. This is what BS astrology is all about. Anything is possible at any point in time, astrology just has some loose rules as to what can happen when, and when one of those events actually occurs, they call it a hit. Sorry. That’s not a science.

  36. llewelly

    Astronomer: A scientist who uses tools to test the accuracy of predictions about objects in the sky.
    Astrologer: A tool who uses objects in the sky to make bad predictions about people and situations.

  37. rob
  38. sophia8

    On the subject of the October 17th email: it’s most probably a viral ad. Look for a movie or computer game coming out on that date.

  39. justcorbly

    My electronics tend to fail when I’m in retrograde. Mercury is on his own.

  40. ND

    Susan Morgan,

    Can you point us to studies that support this mercury retrograde effect? If not where does the understanding of this phenomenon come from? Considering that electronics are historically a recent technology this must be a recent discovery.

    “… think POTENTIAL not FACT.”
    What is there to support the idea that mercury retrograde could *potentially* mean increase in electronics failures? Even for potential, you need something to back it up.

    Also, you might want to understand what science is and how scientists practice it. Having a long history means nothing.

  41. ND

    Oddly enough, my UPS went capput today :)

  42. Ty

    Susan: “Hey, I wonder what’s in this den?”

    Voice from inside den: “It’s totally not lions. We promise.”

    Susan: “Ok! I’ll just head on in then!”

    *Chomp* *nomnomnomnom*

  43. Bart

    I was made redundant a couple of days ago. Of course, I knew this was going to happen for at least a month, but can I blame Mercury anyway? More importantly, if it was indeed Mercury, who can I sue? :-) Anyone have a job for me? I’ll do chemistry for food and beer… :-)

  44. Tyler

    -The failure of astrology is in its unique human perspective. If we were looking down on the solar system from above, if we orbited the sun at a 90 degree angle to the ecliptic, there would be little significance in prograde/retrograde, auspicious/inauspicious planetary motions. Astrology in that case would instead consider the movements of the planets as they orbited in nearly-circular ellipses around the sun, as they seem to group together when we move farther away from the ecliptic, and as they spread apart when we approach, and as they line up as we pass through the ecliptic. “The Grouping” would be significant, as would “The Separation” and “Lining Up,” all VERY important events that affect us with great and terrible influence.

    Anyway, astrologists would explain away this alternative with various excuses meant to draw attention away from the fact astrology has everything to do with our particular placement and perspective in the solar system, and nothing to do with planetary influence.

  45. Nemo

    I think the burning guy is in danger of being overused. Maybe he should be saved for truly special occasions.

  46. IBY

    Phil, you will have to pay for my hospital bill after that burning stupidity.

  47. kuhnigget

    Cutting Susan a little slack (just a little)…back in the day, “astrologers” were actually fairly skilled at observational astronomy. Tycho Brahe, Johannes Keppler – one of their primary motivations for trying to understand the true nature of planetary orbits was so their horoscopes might be more accurate.

    Of course, their horoscopes weren’t more accurate, because horoscopes are bunk no matter who casts them. Astronomers eventually figured that out. Astrologers still don’t get it.

  48. Greg in Austin

    Okay, I really feel sorry for Sue…

    She came here with her side of the argument, made no personal attacks, and tried to defend her beliefs with evidence. She didn’t make it personal. Kudos for that!

    Is it possible to show her how and why she is wrong without making it seem like a personal attack?

    The basis of science is that we can make predictions, and then test those predictions. In that regards, Astronomy and Astrology are similar. Where the difference is, in science, when those predictions are proven false, they are no longer valid. Science relies on the fact that if a prediction is true, it will always be true, in every test. Its why electronics work, why machines work, and why life works.


  49. kuhnigget

    While your sympathy is admirable, Greg, could you please point out the “evidence” Susan used to defend her beliefs?

    I’ll just step into the kitchen for another limoncello while I wait…

    p.s. :)

  50. drksky

    “I’ll just step into the kitchen for another limoncello while I wait…”

    You mean people really do drink that stuff? Smells and tastes like something I would use to polish my dining room table. :p

  51. kuhnigget

    @ drksky:

    Well, I was all out of Pledge…

  52. Hmm.. Let see what thestars holdinstore for us all

    [Picks up the newspaper, flips to the daily astrology column ignoring the cover news of World WarII breaking Out which is, naturally, below a celebrity, shock horror, behavingbadly ..]]

    Ah here we are .. Today’s


    Aries : Today will be your last day before you are either machine-gunned to death, run over by a truck or eaten alive by bedbugs. Make it a good one.

    Aquarius : LOOK OUT!!! LOOK OUT! LOOK OUT! Bugger I just foresaw I will be too late, you’re dead, no need to write anymore .

    Pisces : Feeling something’s fishy and rotten smelling? Yes that‘s a harbinger of your imminent demise. Still got to be better than this current incarnation of yours where you’re wet, smelly and alcoholic! In fact, I predict you’ll be so drunk whenyouread this that I do believ you’ll beleive anything I tell you!

    Gemini : You or your twin &/or other half will die a particularly nasty, drawn out and agonising death today. My condolences either way.

    Leo : Avoid zoo’s, avoid safari parks in Africa and elsewhere, avoid poachers & you’ll be okay. Maybe. If you’re lucky. And quiet. And don’t eat the wrong wildebeest.

    Cancer? : Yep. Sorry.

    Sad-git-hairy-ass : Enough said.

    Libra : Women beware of your tampons today. Men beware of your women! Also avoid scales whether fish, reptilian or measuring – they’ll be bad news for you all month, indeed all your life.

    Scorpio : Today you will die in your sleep in the early morning. In fact, you’ll die before you ever get to read this, so why am I bothering to write it?

    Virgo? : No, you’re not. Unless you’re very young in which case maybe you are. Anyway its none of my business. Avoid eating/ ordering fortune cookies this week and, even more so, avoid misfortune cookies.

    Taurus : Red is not your colour. Beware of matadors or anyone Spanish or non-vegetarian. Avoid china shops, Pamplona & the stock exchange.

    Capricorn : Beware the ides of march, the first of the month, the last of the month, the thirty-first of the month, the sixteenth, thirteen , second, third, fourth, fifth, seventh, eighth , tenth, seventeenth, nineteenth and indeed any day of the month with either an ‘e’, ‘a’, or any consonant at all in it.

    NB. The 13th star sign Ophiuchus (serpent bearer) not included. Seeing as astrological lore holds that Ophuichans are sceptical, logical thinkers who don’t believe in superstitious mumbo-jumbo that’s just as well really. 😉

  53. I also predicted typos & saying “D’oh!” :-( 😉

    This was meant to go in italics and be properly spaced and read WWIII NOT WW II! Even a bad astrologer could predict WW II – now! 😉

    “Hmm.. Let see what the stars hold in store for us all.

    [Picks up the newspaper, flips to the daily astrology column, ignoring the cover news of World War III breaking out which is, naturally, below a celebrity, shock horror, behaving badly .. by saying rude words and engaging in intercourse with somebody they’re not married with two kids to. Meanwhile on page 55 there’s a small paragraph on the LHC working and changing our whole picture of the cosmos wuth marvellous new discoveries and 10,000 people dying terribly in some other poor third world country.]”

    Cynical? Moi?

    Warning : Predictions may or may not have anything to do with Reality. Most likely not.

  54. The fault lies in ourselves NOT the stars.

    Quoting from bad memory and from King something or other I think? ‘King Lear’ mayhaps?

    -Shakespeareusedbardlangague but Anne hathaway with him.. :-)

  55. Jim Jones

    Science rules !!!!!!!!!!!!!!!!!

  56. Willm Shakespeare Says: “Your comment is awaiting moderation.”

    No I don’t!

    Thou comment be awaiting thine moderation sayst I! 😉

    “We apologise for the error in the last edition in which we stated that Mr Fred Nicolme is a defective of the police force. This was a typographical error. We meant, of course, that Mr Nicolme is a detective in the police farce.”
    – ‘Derby Community newspaper’ (Other info. unavailable.)

    Punctuation’s implications :
    The teacher said ‘the Inspector is a fool.’
    ‘The teacher’, said the Inspector,’ is a fool.’

    & for spacing the difference betwixt
    lets see a morality play
    or amorality play

    Commas misplaced, word order reversed
    Can make writer object
    Shout, swear & curse ….

    “Two things are infinite, the universe and human stupidity and I’m not sure about the universe.”
    – Albert Einstein

  57. csrster

    My mp3 player died last week. Then it came back to life again three days later. I may have to start a cult.

  58. … for spacing [implications] the difference betwixt
    lets see a morality play
    or [lets see] amorality play!”

    Since ‘amoral’ isn’t a word that’s used very often these days and morality plays are a thing of the very distant past (ie. Middle Ages / Dark Ages), I’ll explain this one a bit more. Probably over-explain actually but .. shucks.

    A Morality play was a preachy phantomine type theatre that went from village to village acting out moral dramas even preachier and far more devoutly unquestioningly religious than modern soapies back when Kings ruled Europe with swords and knights and all the other fantasy story stuff plus all the smells of unwashed mobs, unsanitised houses, and disease and when everyone held attitudes towards women, slaves, serfs, aristocrats versus Freemen, ad nauseam that were …well qiute literally from thedrak ages.

    ‘Amoral’ means without regarding mortality. Not quite ‘immoral’ which is deliberatley against what is mral but unconcerwned or indifferent towqhether something is moral or not. “Lets see amorality play” then would mean “lets witness or put into action our strategies for the game or life or whatever what is unconcerned with or indifferent to morality. Lets setaside -for play purposes – any questions over the morality of what we’re doing.”

    Quite a difference! All in onespace. Or rightly one space. 😉

  59. D’oh!

    That should read :

    “A Morality play was a early type of theatre … back when Kings ruled Europe with swords and knights and all the other fantasy story stuff plus all the smells of unwashed mobs, unsanitised houses, and disease and when everyone held attitudes towards women, slaves, serfs, aristocrats versus peasants, ad nauseam, that were … well .. quite literally from the Dark Ages.” 😉

    Be execllent if we could actually correct such typos and grammar bad stuff andspacing erors ad nauseam here wouldn’t it? *SIGH* :-(

  60. kuhnigget

    @ csrster:

    If you dangle your mp3 player from a string and fly it around a cardboard tree in front of a home movie camera, I’ll be your acolyte!

  61. kuhnigget Says: October 4th, 2008 at 1:05 pm
    @ csrster: “If you dangle your mp3 player from a string and fly it around a cardboard tree in front of a home movie camera, I’ll be your acolyte!”

    Nup, I won’t be! 😉

    Not until its healed at least twelve deaf people, cured Phil of his ABBA worship and exorcised the demons that possess people to like boy bands and Michael Bolton anyway! 😉

  62. Good one NoStarsDumUS! 😉 😀

    But with “Taurus : Red is not your colour. Beware of matadors or anyone Spanish or non-vegetarian. Avoid china shops, Pamplona & the stock exchange.”

    Umm .. I think we WANT bulls in the stock market don’t we? Esp. right now when its such a bear market. Or generally going down the gurgler … :-O
    😉 :-(

  63. Greg in Austin


    Mmmm… limoncello! Best served very cold in a frozen shot glass!

    I was speaking of Sue’s explanations of Astrology, that support her beliefs, not necessarily evidence to support Astrology itself. Perhaps I should have used a different word for that.


  64. Gary Ansorge

    Willm Shakespeare:

    Please note:
    Apostrophes are vital
    to communication,,,
    ,,,as in,,,

    I can’t believe IT’S not butter!
    I can’t believe IT. Snot butter!

    GAry 7
    PS – OK! SO! It took a period AND an apostrophe.

  65. Daniel

    As long as Susan is hot and has a youtube channel on horrorscopes (yes…horror)…ill belive anything she says 😀

  66. Troy

    Someone else mentioned it, but I’ll reiterate. You can only observe retrograde motion on a superior planet. Mercury being in an inferior orbit just tends to bob up and down in the east or west. Actually if you see it at all you’re pretty lucky and/or skilled. It never really escapes the glow of the sun.

  67. ND

    According to the wiki article on retrograde (I posted link, awaiting moderation), there is this quote “… traditionally thought to be unlucky or inauspicious, as it went against the ‘natural’ order of movement,…”

    Against natural order of movement? Meaning it goes against the human sense of natural order of things.

  68. I worked out my own horoscope today and it said that my predictions today would be wrong because of Mercury, which turned out to be wrong because it was right, which meant it was right because it was wrong…

    ‘scuse me, I need to lie down…

  69. Charon

    Troy: you are wrong. Mercury does undergo retrograde motion (at perigee). Draw a picture (and remember it orbits faster than Earth does).

  70. Charon

    …although I am compelled to point out that when Mercury is at perigee it’s also in conjunction with the Sun, which would make it difficult to observe in practice.

  71. Clair

    I learned about Mercury and its retrograde about 14 years ago. I was working for a friend of mine and he told me about it and told me to expect an increase in (computer) support calls, etc. At the time, I thought astrology was a bunch of hooey, but being human, I noticed more calls and more work. I even remember saying something along the lines of, “I think astrology’s crap, but this Mercury retrograde thing seems to perhaps hold water.” I would later say the same thing about my “Saturn return”.

    Total. Selection. Bias. Later and for whatever reason, I started to question my own “belief”/statement. I would notice increases in support calls and I would look it up… Is Mercury retrograde? No? I thought so. I would continue on my business.

    I have a friend who is completely immersed into astrology. He does all kinds of charts for me. Every time I have a “major” event coming up, he goes and looks it up to make sure the date is good. He’s invested so much money into becoming a “professional” astrologer. At one time I tried to talk with him about it, but he’s so far into it, I think he’ll never come out. So, I just don’t talk about it with him.

  72. ND


    A story of enlightenment and hope. It’s good to hear about them :)

    Who knows, years down the road your experience may help your friend look outside the box.

  73. Brian


    The statistics recently at my household strongly support the Mercury Hypothesis. Four days ago I turned on my computer and it immediately made a really terrible frying sound and shut down. Basically, it died. My new Mac just arrived at my front door via UPS.

    Which caused me to think: Shouldn’t we see higher sales of appliances and gadgets while Mercury is in retrograde? These stats should be available somewhere. If my computer’s failure was indeed part of a wider pattern, we should almost certainly be able to detect that pattern based on the behavior I exhibited immediately following the technology failure I suffered. Sales get charted. To put it mildly.

    I doubt there’s a CEO of an electronics company, or a person in charge of inventory at a retailer, who wouldn’t want to know if there is a higher probability (think POTENTIAL) of a sales rise of any significant amount during certain periods. Managing inventory well — not running out of product but also not stocking too much — has real bottom-line benefits.

    Businesses are used to making decisions on educated guesses, as in sales there are no ABSOLUTE PREDICTIVE TOOLS. You make the best choice you can based on past observed patterns of consumer behavior. Data on those patterns is valuable. In other words, there is a massive market out there for someone who could truly predict periods when it is MORE LIKELY that people would have to replace broken devices.

    Yet I have never heard of a single business that adjusts its inventory based on Mercury. That’s so weird. They’re throwing away money!

    One more observation from my own experience: For a human male, there is an inverse relationship between open contempt for astrology and getting laid.

  74. nrs

    i vote for sue. astrology is not to be taken literally guys :) it’s just cool beans

  75. Billy

    when I first heard “mercury in retrograde” I was like… okay, astrologers ascribing occurrences in life to astronomical events, same as normal, but then I thought:
    Wait a second, Mercury is not a superior planet, how can it be in retrograde motion?

    apparently these people say that when an inferior planet (or I suppose any planet) is on the other side of the sun and traveling towards the west, it is in “retrograde motion”.


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