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Croydon Astronomical Society

The “Great” planetary alignment of 25th January

 

Much as though we welcome the media’s recent interest in astronomy they do talk rubbish at times. One such topic is their prediction that all the planets will “line up” on 25th January. There is some element of truth in this but, as is often the case, much of the information in the press and online is exaggerated or simply not true.

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If you have seen picture of all the planets in a line going outward from the sun then this is absolute rubbish. It will happen – in about 400 billion years (long after our sun is dead) but it won’t happen this month.

If by planets in a line you are looking for planets in a line across the sky then this is true. But they all orbit the sun in a relatively flat plane, so they are always in a rough line.

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Now, to manage expectations. There are eight proper planets in our solar system (as far as we are aware). Mercury is very close to the sun and so can only ever be seen either at sunrise or sunset. At the moment it appears at sunrise so we can discount that planet. We also discount the Earth so we are now down to six planets. But Neptune and Uranus are too feint to see from Croydon without a telescope – and are pretty boring even with one – so that leaves four.

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Now, it is true that Venus, Mars, Jupiter and Saturn can all be seen in the sky on the night of 25th January. This IS exciting as for much or last year there weren’t any planets visible in the sky at night. But it is not unique to 25th January. We have been showing visitors these four planets for a good few weeks and can continue to do so until early February when we lose Saturn. They are up there tonight if you look. The other three will remain visible into March.

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Astronomy is exciting, but it is not THAT exciting.