The Giant Planets: 8 Facts You Won’t Know

Our Solar System is made up of 8 planets, and of these, 4 are known as the Giant Planets: a planet much larger than Earth. Join us on a journey of discovery to the Giant Planets – Jupiter, Saturn, Uranus and Neptune – as Professor Craig Underwood shares 8 fascinating facts about them…


1. Jupiter’s mass is more than twice that of all the other planets combined. It has a diameter larger than the smallest stars. If Jupiter was just 100 times heavier, it would ignite and become a star itself.

2. Jupiter doesn’t orbit the Sun! Jupiter is so massive, the barycentre of its orbit (the center of mass between two objects) lies just outside of the body of the Sun.


3. The density of Saturn is less than that of water. If you could find a bath big enough, you could float it!

4. Saturn is known at the ringed planet – but it is not the only one. Jupiter, Saturn, Uranus and Neptune all have rings. So does Earth, but ours consists of belts of artificial satellites and is less than 60 years old!


5. Uranus was the first planet to be discovered since ancient times. Although William Herschel “discovered” it, Uranus had been observed many times before, but had always been thought to be a just a faint star. At first, Herschel thought he had discovered a new comet!

6. Uranus is tilted over onto its side. This means that as it orbits the Sun, each pole in turn points at the Sun. Although Uranus rotates in just 17 hours 14 minutes, the “winter” side of the planet doesn’t see the Sun for 21 years, whereas the “summer” side has continuous daylight. As a result, the weather patterns on Uranus are very different to those on Earth.


7. Neptune was discovered by mathematical calculation based on observing small errors in the expected position of the other planets.    

8. Neptune is the solar system’s other “blue planet” – just like Earth. But on Neptune, the sky is blue due to the absorption of red light by crystals of frozen methane gas. On Earth the blue sky is due to the scattering of light by air molecules.

If you’d like to learn more about the Giant Planets, make sure to check out Craig’s online courses with the Institute this term. Whether you’re a budding space explorer, a planets expert or somewhere in between, everyone is welcome! The Gas Giants: Saturn – A Science Perspective is taking place on 16 February and The Ice Giants: Uranus and Neptune is happening on 16 March.

A Tribute to Gordon Bridger

Hon. Alderman Gordon Bridger

Gordon Bridger, who died on November 27 2020, aged 92 gave fifty years of his life to Guildford. His passing was noted with tributes from the many organisations and individuals who valued his intellect, his energy and drive and, above all, his sense of humour. He could be guaranteed to raise a laugh – whatever the occasion.

Gordon Bridger

Gordon was born and brought up in Argentina (a fluent Spanish speaker). He arrived in the UK aged 19 having worked his passage as a crew member of a merchant ship. Not a very able seaman, he did better as a student at the London School of Economics and after graduating with distinction he went on to take an MSc in Agricultural Economics at Manchester University. His career “developed” all over the world – first in colonial Rhodesia (where he met his wife, Jean) then with the United Nations in Ethiopia, where adventures ensued worthy of portrayal by Indiana Jones….There followed a posting to Chile. After serving as senior economic adviser to the UK Ministry of Overseas Development (more adventures in Africa) he became Director. (For details of Gordon’s exciting life see his book How I failed to save the World – there is a copy in the GI Library).

So how did this man, whose career had criss-crossed the world, come to be the much admired, much loved and inspirational pillar of the Guildford community? He took early retirement in the late 1960s and settled with Jean and his children in Harvey Rd. As a Consultant (economics) his time was his own to organise and his energy was limitless. He set about getting to know the town and its people. He and Jean founded the Holy Trinity Amenity Group (HoTAG); he joined the Guildford Society, later becoming Chairman; and in 1972 he discovered the Guildford Institute – or more accurately – the Library. He was very interested in antiquarian books and on investigating the upper shelves he was surprised to find (covered in coal dust) a collection of first editions by early African explorers – Burton, Speke, Selous and Baker – as well as works by Gertrude Jekyll and Joseph Conrad.  He immediately joined the Institute (annual subscription £1). His interest (and membership) was not exactly welcomed by Miss Gibbons, Secretary and Librarian.  Sharing his excitement was Russell Chamberlin (author and historian); the two men decided to “get more involved”.

There is a very amusing account (recorded in The Keep Nos 68 and 69) of how Gordon and a handful of friends hijacked the Management Committee in 1976 and went on to transform the Institute from being a moribund billiards club, occupying a badly neglected building, into something that once again resembled the bustling cultural centre it had been 80 years earlier. But this only came about because Gordon inspired so many people to join in the task of recovering the treasures that lay behind closed doors. Volunteers rescued Victorian photographs, portraits, postcards and playbills. Two young women set about cleaning 10,000 books in the Library and in the process discovered the Bishops’ Bible of 1602, still bearing its shelf classification mark L57 (now to be seen in the Cathedral where it resides on permanent loan). The archived collections have national standing and the Library is a member of the Association of Independent Libraries in the UK.

Matthew Alexander, then curator of Guildford Museum, volunteered his services to sort out the fascinating jumble of local history, and Gordon persuaded David Nye, a local architect, to join the Committee. He crawled all over the building and supervised the contractors who carried out the necessary repairs .In the 1980s Jean Bridger with her friend, Alison Farara, launched The Beano – serving delicious veggie lunches on Fridays. By 1986 the Institute had gained a new lease of life.

The Institute story demonstrates exactly the man Gordon Bridger was all his life: if he saw something needed to be done, he didn’t wait for others – he got on with doing it. He brought his intellect, drive and energy to politics when elected to the GBC as a Liberal Democrat in 1991. A passionate campaigner (remember the demolition of the Sydenham Rd Car Park?) he served in order to achieve. He was a formidable opponent in debate and lent his experience and skill to the Guildford Vision Group in later years. He suffered several serious health problems but it was typical of Gordon that even when recovering from a cancer operation, he was out campaigning for the charity GUTs (Guildford Undetected Tumours).

Many people have said that Guildford owes Gordon Bridger a “huge debt”; the same could be said for the Guildford Institute. We mourn his passing.

Margaret Westwood

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