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The Rotating Moon – 60 Second Adventures in Astronomy (5/14)


60-Second Adventures in Astronomy. Number
Five: The Rotating Moon. Whenever you look at the moon from Earth, it always looks
similar. Different parts are illuminated at different times, but oddly we always
see the same features. The moon never turns its back on us, much like the rules
of etiquette when you visit the Queen. So does this mean the moon doesn’t rotate?
Well no, because then as it orbited us we would see first it’s front, then it’s left
side and then it’s rear. What actually happens is that the moon rotates
exactly once every orbit, which takes a bit less than a month. So though you’d
see it spinning from an outside perspective from the Earth, we all see
the same side. In fact we didn’t get a proper view of the far side of the Moon
until 1959, thanks to a Soviet space probe. The moon used to spin a lot faster,
but over millions of years the gravitational pull, or tidal force, from
the Earth has slowed the moon down. The same thing has happened to most moons of
large planets but it doesn’t work both ways, because while the moon is spinning
once every orbit, the Earth is rotating about 30 times faster. So from a vantage
point on the moon you’d get to see us from all sides if you stuck around long
enough.

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Comments
  • i think the voice acting is done by a British comedian, i recognize his voice from the BBC show QI where he is a recurring guest
    i bet that hiring him wasn't cheap

  • The opening animation of the moon phase shows an 'old' moon phasing to a 'new' moon, when of course it actually goes the other way. We expect better of the OU!

  • You would be correct if the scene were explicitly in northern temperate latitudes. Well spotted, but we show a waxing crescent ending up as full Moon (not new Moon as you wrote). However, for those in Australia it would look as shown. The OU is global, so that's OK 🙂
    A more important point is that the phase takes several days to change by this much. Lovers on a balcony would have to be there for an unfeasibly long time however affectionate they felt – but we speeded it up for humorous effect.

  • Was this what all the fuss was about in Private Eye? If the Open University has ambitions to be global and a university it needs to do better. So what happened to all the comments that prompted Lord Gnome's attention?

  • I am amazed how the moon can spin in such a perfect speed that it never turns around. Think about it. It's almost. Design spinning. 🙂 *Can almost hear the atheists going crazy in the room*… 😛

  • The Moon's rotation is not shown backwards. Please refrain from using offensive language. The Moon's phases (where its visible shape changes) is nothing to do with its rotation. The waxing (growing) crescent Moon looks D-shaped when seen from northern latitudes and C-shaped when seen from southern latitudes (because it is seen the other way up).

  • Here's a site where schoolkids show that they know that lunar phases look different when seen in N and S hemispheres: SLASHSLASHresources.woodlands-junior.kent.sch.ukSLASHtimeSLASHmoonSLASHphases.html
    (I cant post web addresses, so you will need to re-insert the slash symbols)

  • And someone who wants to leave you defenseless is much smarter right? GO TO SYRIA IF YOU WANT "NO GUNS"..HECK GO TO CHICAGO

  • are you retarded, it didnt always spin this way, the tidal forces of the earths gravity caused it. i guess all the other moons in the solar system are designed spins too, but designed for who?

  • In case anyone is wondering, this is called "Tidal locking". The gravitational pull is significantly higher on the nearer side of the moon, so any rotational momentum it had previously has been counteracted by Earth's gravity, leaving us with one side always being pulled more than the other, "locking" it in place

  • I was enjoying it until x amount of hypothetical years ago the moon did something else, I would like to see proof of that. Theory always parading as science, science is not a consensus. Lots of people like money too

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