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News Eagle - Hawley, PA
  • Andromeda Galaxy coming our way

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  •    This may sound like a supermarket tabloid story but...     
      According to prognosticating astronomers, the Andromeda Galaxy is heading right for us and will collide with the Milky Way Galaxy in a number of years.
          Most haven’t heard of this purported accident waiting to happen. It’s just as well, for there are always some people who get uptight about anything!
           Also known as M31, the Andromeda spiral galaxy and the Milky Way’s spiral - with Earth included- are hurtling towards each other at 270,000 miles an hour- or so.  Even at this incredible speed, however, you needn’t stay awake nights worried over it (but if you do, you may as well get some stargazing in!). Given the immense distance - 2.5 million light years -  separating the two galaxies, they would not collide until two to five BILLION years from now. As I said, a “number of years.”
    Of course a lot can happen before then.
            M31 is the most easily visible galaxy beyond the Milky Way and is visible to the unaided eyes as a fourth magnitude, fuzzy oval. The best time for evening viewing is in the autumn. In late May/early June you can start to see it around 1 a.m., low in the northeast, but to see anything in the Universe more clearly, you should wait for it to rise further. A dark night is needed and you need a spot where light pollution isn’t a problem in that direction. Binoculars will give a better view.
          It is a wonder to realize that even as you gaze at M31, it is gaining in brightness as it is coming towards you. Because of the great distance the brightening is not detectable in anyone’s life span.  
        Many galaxies are observed in the act of collision, as revealed by deep space photography.
       Galaxies actually merge as the collide. Few stars would actually hit each other bit would pass by one another; nebulae (cosmic clouds) do collide and interact. The merger takes a very long time. The results are disheveled, misshapen galaxies and bursts of star formation as nebulae are compressed. Some stars are thrown out into long, curving tails formed by tidal forces.
        Can you imagine how starry the sky would be?!
        Astronomers deduce the relative motion of M31 and other galaxies by the shifting of lines in the galaxy light’s spectrum of colors. These lines denote elements making up the billions of stars in the galaxy, mostly due to hydrogen. M31’s spectral lines are shifted towards the blue end of the spectrum, meaning it is coming towards us. Most galaxies are speeding away from us, and are red-shifted. The shifting is caused by the “Doppler effect,” which also applies to the shifting frequency of sound that you hear as a vehicle with a bad muffler races past you breaking the speed limit with hopefully a police car behind it.  The noise of the engine rises and falls in pitch as it goes by.
    Page 2 of 2 -     P.S. In case you wanted to know, your homeowner's insurance policy probably won't cover galactic collisions.
        New moon is on May 28.
       Send your hellos to news@neagle.com.
    Keep looking up!

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