If you look up at the night sky on a clear night you will gradually see hundreds and hundreds of stars. In fact we know there are hundreds of thousands of millions of them, each one of them a star like our Sun. Around our Sun there orbit a number of planets and around all the other stars in the universe there must be planets of different shapes and sizes. Astronomers know of the existence of about 170 of these, light years away from us and discovered, so I read, by a process called microlensing.


If you were asked how many planets there were in our solar system you might say that there were eight or nine. Officially now there are eight although Pluto, the planet most recently discovered – as recently as 1930 – has now been demoted and is officially regarded only as a dwarf planet. It is also a very long way away – so far away that it takes 248 years for it to orbit around the Sun compared to the 365 days it takes our Earth. But because it is quite small and exists in an area where there are lots of other things floating around – the Kuiper Belt – it has been denied its planetary status by astronomers in the last ten years. However, this is still controversial and not everyone agrees with it.


But Pluto is in the news again this week as the US spaceship, New Horizons, which was launched nine years ago in 2006, will become the first space craft to visit Pluto.


Having journeyed through space for more than three billion miles, New Horizons will come within 7,800 miles of Pluto at 12.49pm Tuesday, 14th July UK time. As it hurtles past it will take photographs and make measurements of the distant planet which will tell us something about its composition and atmosphere.


But the story of Pluto’s discovery is not without interest. It was discovered in 1930 by Clyde Tombaugh. Although he was the first to discover it and he later helped to found the New Mexico State University’s astronomy department he didn’t start out as an astronomer. He grew up on a farm in Kansas and became interested in the stars and the planets as a boy. He built all his first telescopes out of farm machinery and the telescope he used to search for Pluto was made from things he found on the farm when he was 24. Other astronomers had predicted the existence of Pluto but Clyde Tombaugh, using a telescope made from a grain elevator, a cream separator and an old car axle together with lenses he had ground himself, was the first to see the planet. Clyde died in 1997 and, fittingly, when New Horizons was launched some of his ashes were sent into space onboard the ship.


I am always impressed by stories like this. It is a truly human trait to wonder at the stars and the majesty of creation, and to want to explore its vastness. This is something the Psalmist felt as he gazed at the night sky over Jerusalem maybe three thousand years ago:


When I look at thy heavens, the work of thy fingers,
the moon and the stars which thou hast established;
what is man that thou art mindful of him,
and the son of man that thou dost care for him?

(Psalm 8 v.3-4)



Isaac Watts expressed something similar in one of his hymns in the eighteenth century:

Eternal Power, whose high abode
Becomes the grandeur of a God:
Infinite length beyond the bounds
Where stars revolve their finite rounds.


But what particularly caught my eye with this story was that Clyde Tombaugh also helped to found a new church in Las Cruces, New Mexico. Not only that when he died they put in a very striking stained glass window in his memory in the Unitarian Universalist church there of which he was a member. It is a very large and attractive window, eight feet tall and eighteen feet wide and shows the figure of Clyde Tombaugh making one of his lenses and the solar system stretched out in the night sky including Pluto. Appropriately enough it also includes the church’s motto: “That all souls shall grow into harmony with creation”.

If you would like to see the window this link should take you there:


Picture credit at the top of the page is “ForestWander Nature Photography” Wikimedia Commons

One thought on “The discoverer of Pluto

  1. This story of Clive Tombaugh is extremely interesting and an excellent illustration of the complementary of religion and science. Thanks, David.


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