Category Archives: Astronomy

The Northern Lights head south

In recent days, the aurora borealis, better known as the Northern Lights, have been visible at more southerly latitudes than usual thanks to solar storm activity.

If you tried to have a look but were scuppered by the weather, or like us at the Science Museum you’re just too far south, enjoy these images of the aurora from our picture library instead.

The aurora and icebergs in the Arctic, as depicted in the Illustrated London News, 1849 (Science Museum).

This 19th century magic lantern slide shows the aurora (Science Museum).

The Northern Lights over Iceland, 2005 (Jamie Cooper / Science & Society).

Of course, if you’re far south enough, you’ll be looking for the Southern Lights instead. The aurora australis is particularly elusive, as there’s a lot less inhabited landmass at high southern latitudes than in the north. It’s also been putting on a more widespread lightshow in recent days. But it would be hard to beat this view…

A time exposure of the Southern Lights, as seen from the Space Shuttle Endeavour, 1994 (NASA / Science & Society).

Last chance to see: Thomas Harriot

Monday marked 401 years since Thomas Harriot made the first recorded astronomical observation with a telescope - so one year since we opened our Cosmos & Culture exhibition celebrating Harriot and other astronomers.

For the last year, we’ve been lucky enough to have some of Harriot’s drawings on display, but for their long-term preservation it’s time to remove them from the light. This weekend is your last chance to see the centuries-old originals before we return them to their owner’s care and replace them with facsimiles.

Harriot’s first drawing of our Moon pre-dates any other telescopic observations. But Galileo beat him to it in discovering moons around Jupiter. Harriot probably read Galileo’s Sidereus Nuncius around July, but by then Jupiter was too near the Sun for him to check it out. This drawing shows his first observations of the moons in autumn 1610. The first night wasn’t too successful – he noted, ‘I saw but one, and that above’ – but over the next year he made 98 further observations and tracked all four Galilean satellites.

Harriot tracks the Galilean satellites (Lord Egremont/West Sussex Record Office, used with permission)

By winter Harriot had turned his telescope on the Sun, risking blindness by viewing it directly with only mist to shield its fierce glare. In December 1610 he saw sunspots – one of several astronomers to independently discover them around the same time.

Harriot notes 'three blacke spots' on the Sun (Lord Egremont / West Sussex Record Office, used with permisson).

So with all these achievements, why isn’t Harriot as famous as Galileo? Well, unlike his Italian counterpart he already had rich patrons, so didn’t need to publish his work to attract sponsors. He may have also preferred to keep a low profile after a brief stint in prison as a Gunpowder Plot suspect. After his death, his astronomical papers lay undiscovered for over 150 years, so not many people have seen them in the last four centuries. If you’re in London this week, take a good look while you still can.

Catching the Sun

So, did any of you make it to Easter Island to see last weekend’s total solar eclipse? The path of totality crossed very few landmasses, so observing this eclipse was for the most intrepid travellers. Next weekend marks the 150th anniversary of a solar eclipse which was somewhat less remote – but observed by some very intrepid travellers, who for the first time used photography to settle a scientific debate. 

On 18 July 1860, Warren De la Rue and his team eagerly awaited the eclipse in their makeshift wooden observatory at Rivabellosa in northern Spain. The observatory and its contents – some two tons of apparatus – had been transported from Plymouth to Bilbao on board HMS Himalaya and then by stagecoach to Rivabellosa, where De la Rue persuaded a local farmer to set aside his threshing floor for the observatory.

De la Rue's eclipse observatory as shown in the Illustrated London News, 1860 (Science Museum).

The key piece of apparatus was the Kew Photoheliograph, designed by De la Rue a few years before. The first instrument specifically designed to photograph celestial objects, it was regularly used at Kew Observatory to record images of the Sun and Moon. The astronomers hoped that its wet collodion plates, with their short exposure times, could record the prominences visible during a solar eclipse. At the time it was not known whether these were part of the Sun, or an effect of the Earth’s atmosphere.

The Kew Photoheliograph is on display in Cosmos & Culture (Science Museum).

Working in the hot Spanish summer, the astronomers only had a few minutes to develop each plate before the wet collodion dried. But they successfully recorded prominences on several plates – De la Rue described them with names including Cauliflower and Boomerang. When the photographs were compared with ones taken by Fr Angelo Secchi 500km away at Desierto de las Palmas, the two sets were so similar that they proved prominences are intrinsic to the Sun.

An expedition photograph of the eclipse before totality (Science Museum).

For a lively account of the Rivabellosa expedition – including the tale of how the observatory almost burned down just minutes before the eclipse(!) - check out Stuart Clark‘s The Sun Kings.

FM: No Static At All

Our car is still fitted with a cassette player. Albums from long ago (Steely Dan and Beatles are current favourites) provide regular entertainment on journeys and are also enjoyed by the younger members of the family. I suppose we should have moved over to a CD player or something more exotic still, but somehow it seems unnecessary while the cassettes hold out (now 25 years old plus and still working fine!)

8-Track audio tape

8-Track tapes like this one dominated the American in-car market between the 1960s and 1980s but were then killed off by the improved audio quality of the handy cassette. (Science Museum/Science & Society)

I suppose the same can now be said of the car’s FM radio, given government Culture Minister Ed Vaizey’s announcement last week that the digital radio switch-over will happen, but only when a vast majority of listeners have voluntarily adopted digital radio over analogue.

He went on to highlight in-car radio as one of the biggest challenges facing the digital switch-over. This because of the difficulty in receiving digital signals while moving at speed. Once again, why bother to spend money on new technology when the old still works just fine.  He threw down the gauntlet to the car manufacturers to work towards some solutions.

But, although we choose perhaps to forget it, this tendency to delay novelty in favour of that which already works is by no means uncommon.

Smoothwell electric iron, 1935

Smoothwell electric iron, 1935 (Science Museum/Science & Society)

Take another domestic technology – the electric iron: it’s changed little over at least 70 years. Neither, by and large, has the basic form of the bicycle, now well into its second century of pedalling.

Rover 'Safety' Bicycle, 1885
Rover ‘Safety’ Bicycle, 1885 (Science Museum/Science & Society)

And at the other end of the cost spectrum – we still use rockets adapted from 1950s inter continental ballistic missiles to launch satellites and probes into space – they exist, we know lots about them, they do the job – why fix things that aren’t bust?

A Delta 2 Rocket launches the Kepler space observatory in 2009

A Delta 2 Rocket launches the Kepler space observatory in 2009 (NASA/Regina Mitchell-Ryall, Tom Farrar)

So novelty is no guarantee of successful innovation. Maybe Steely Dan had something to say about it in one of the songs we were listening to in the car: ‘FM – No Static at All.’

From Planck to pigeon poo

The European Space Agency has just released the first all-sky map from the Planck satellite. The centre of the map is dominated by purple swirls from the dust around our Galaxy, but Planck’s main business is to look closely at the blobby structures visible in the map’s outer regions. These ’blobs’ show temperature fluctuations in the Cosmic Microwave Background (CMB), the remnant radiation from the Big Bang. Irregularities in the CMB became the seeds of today’s galaxies.

Planck's all sky survey (ESA, HFI and LFI consortia)

The fluctuations in the background radiation were first mapped by NASA’s COBE satellite, launched in 1989. An instrument on board also measured the CMB’s spectrum. FIRAS’s moving mirrors created interference patterns in a radiation beam, enabling the precise spectrum to be reconstructed. To the delight of scientists, the results perfectly matched the predictions of Big Bang theory.

This prototype mirror mechanism for the FIRAS instrument is on display in Cosmos & Culture (Science Museum).

The FIRAS prototype is on loan to us from the kind folks at the Smithsonian Institution’s National Air and Space Museum in Washington DC.  NASM’s display about the 1964 discovery of the microwave background features one of my favourite objects in any museum, anywhere. Arno Penzias and Robert Wilson initially thought that an annoying background hiss from their radio antenna was caused by pigeon droppings, and used this trap to try and capture the pesky critters. It turned out they’d accidentally found what other scientists had been looking for – the Big Bang’s echo.

Blame the Satellite

Blame the manager, the ref, the team… I blame the satellite. Before the space age and communications satellites there was no live TV coverage of the World Cup and we could all get on with our work and jobs around the house and garden.

Robomo lawnmowing machine, 1966

Robomo lawnmowing machine, 1966 (Science Museum/Science & Society)

It was just another international sporting event covered by radio, recorded television reports and on the back pages of the newspapers. There was less tension, less hype and, to put it bluntly, less interest. Oh, how times have changed.

Master Football Game, 1945-60

With no live World Cup football on TV until the 1960s slot machines like this Master Football Game were popular, 1945-60 (Science Museum/Science & Society)

Telstar relayed the very first TV pictures by satellite in 1962. The event was a technological triumph, a harbinger of near-real time global culture and, not least, the inspiration for one of the most distinctive pop records ever made.

First live TV transmission by the Telstar 1 satellite, 1962

Fred Kappel of AT&T speaks to a trans-Atlantic audience during the first live TV transmission by the Telstar 1 satellite, 1962

Telstar 1 Satellite (replica), 1962

Telstar 1 Satellite (replica), 1962 (Science Museum/Science & Society)

Telstar, though, occupied an orbit that made continuous broadcast impossible. After a while the satellite would dip below the horizon and the signal it was relaying would be lost.

The development of more powerful space rockets allowed satellites to be launched to the far higher geostationary belt around the Earth’s equator. At an altitude of 36,000m, the satellites’ orbital rates match that of the Earth’s rotation so ‘anchoring’ them at fixed points above the horizon.

Today’s World Cup is being brought to our homes by a fleet of such communications satellitest that collect and distribute the action from South Africa to countries around the world.

BSkyB satellite receiving antenna

BSkyB satellite receiving antenna, 2010 (Doug Millard).

 This can then be beamed back up to a set of Direct Broadcast Satellites (DBS), also occupying the geostationary orbit, which relay them down to the satellite dishes that adorn our walls and roofs.

It is the DBS industry that has invested in the English football league and especially the Premiership, so helping make it the most successful domestic football league in the world. But that’s still no guarantor of success on the pitch…

Corrosive Atmosphere

A few days ago I drove past the ‘umbilical’ tower for NASA’s new (but now postponed) Ares rocket programme.

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Ares launch tower at Kennedy Space Centre, 2010 (Doug Millard)

Although smaller it is reminiscent of the far taller structures of project Apollo.

Apollo 13's Saturn V and tower, 1969

Apollo 13's Saturn V and tower, 1969 (NASA)

Both Ares and Saturn were ‘mated’ to their respective towers inside the vast Vehicle Assembly Building (VAB) and then rolled out on a ‘crawler’ to launch pad 39 A or B at the stately rate of 1 mph. The towers for the soon to be terminated Shuttle programme, on the other hand, were permanent fixtures at each of the two pads with a Shuttle, standing alone on its launch platform, brought ever so carefully the 3 1/2 miles to its designated pad.

Space Shuttle Endeavour 'crawls' to its launch tower at Pad 39A, 2010

Space Shuttle Endeavour 'crawls' to its launch tower at Pad 39A, 2010 (NASA)

Why did NASA revert to bringing Ares vehicle and tower out to the pad for each launch before returning the vacated tower to the VAB? Rust.

The Kennedy Space Centre is situated on the Florida coast and is therefore permanently doused in salty, moist air. The Shuttle launching structures required near constant attention to deal with the corrosion problem. Rusting is an electro-chemical process so, by definition, generates electricity – the first wet cell batteries exploited the principle.

Bichromate cell, 1876

Bichromate cell, 1876 (Science Museum/Science & Society)

And this signals another headache NASA had to deal with when the mighty VAB itself was being constructed. The building is enormous, comprising almost 100,000 tonnes of steel work, and still one of the largest by volume in the world (it had to be to be able to enclose the 363’ tall Saturn V rocket).

Construction of the VAB, 1964

Construction of the VAB, 1964 (NASA)

But its steel pile foundations have to reach down some 50 feet to solid bedrock… through a salty solution – perfect conditions for electro-chemistry to do its rusty worst! NASA realised that if they did not protect the steel piles they would not only have corroded the steel beams and piles but also, in effect, turned the whole VAB into ‘the world’s largest wet cell battery’.

Celebrating James Ferguson

Walk into any museum curator’s office and you’ll encounter a mass of books and papers. It’s not that we’re messy – well okay, I am – but a lot of the material we use can’t always be found on the web. Even on Stories from the Stores.

One of my favourite books on my shelves is Astronomy Explained upon Sir Isaac Newton’s Principles by James Ferguson, who was born 300 years ago last Sunday. Published in 1785 (the first edition was 1756), it’s intended ‘for those who have not studied mathematics’ and contains beautifully illustrated explanations of how the Solar System works.

Ferguson in his study. (Science Museum)

Ferguson travelled around England giving lectures on natural philosophy. These were hugely popular, aided by the ingenious models he built to demonstrate scientific phenomena.

Ferguson's wooden orrery (c. 1755) uses hand-driven pulleys to demonstrate the motion of the Earth, Sun and Moon. (Science Museum)

Before moving to England and making his name as a lecturer, Ferguson lived in Edinburgh where he made a living as a miniature portrait painter. These pencil-and-ink miniatures show his talent:

Portrait miniatures made by Ferguson in the 18th century. (Science Museum)

And although you can’t find everything on the web that you can in a curator’s office, you can find out more about Ferguson for yourself by reading his autobiography here, and enjoy Astronomy Explained here.

For she’s a jolly good Fellow

On Tuesday I attended our annual ‘Fellows of the Science Museum’ reception, in which we recognise the contributions of leading scientists and educators. This year we were particularly celebrating female scientists, with a speech from new Fellow Jocelyn Bell Burnell

Jocelyn in 1968. (Science Museum)

In 1967, Jocelyn was a PhD student at the Mullard Radio Astronomy Observatory in Cambridge. Her job was to analyse data from one of the telescopes for the characteristic twinkling of quasars. One day she noticed a ‘bit of scruff’ on the telescope’s charts and, rather than dismiss it as interference, decided to investigate further. It turned out to be a pulsed signal, always coming from the same patch of sky and repeating at regular intervals. For a short time, the Cambridge team had to consider the possibility that it was a signal from an alien civilisation – they jokingly dubbed it LGM-1, for Little Green Men.

The signal from the first pulsar appeared on the cover of Joy Division's 'Unknown Pleasures' LP. (Science Museum)

Jocelyn and her supervisor Antony Hewish (who’s also a Science Museum Fellow) soon detected signals from other parts of the sky and realised they had found a new class of cosmic object – a rapidly-spinning dense star. They are called pulsars and over 1800 are now known. 

Part of Jocelyn’s telescope is on display in Cosmos & Culture. It might take you a while to spot it, as it doesn’t look anything like your average telescope:

The pulsar array is now retired. During use, sheep kept the 4 acres of grass neatly trimmed. (Alison Boyle)

Jocelyn was recently the subject of the BBC’s Beautiful Minds.  Beauty is the theme of next Wednesday’s Science Museum Lates, and Jocelyn will be there talking about her work and inspirations. Hope to see you there!

Sweet Caroline

Great to see Caroline Herschel making the Royal Society‘s list of influential female scientists. Although she’s often been overshadowed by her brother William, her own contribution to astronomy was immense.

In 1772, Caroline escaped a life of domestic servitude in Hanover to join her brother in Bath. William had forged a successful musical career and needed someone to keep house. Caroline, with her fine soprano voice, joined him in many performances.

Caroline sang at this performance of Handel's Messiah conducted by William. (Science Museum)

However, she soon discovered that what William really wanted was someone to indulge his passion for astronomy. ‘Almost every room turned into a workshop’, she noted, as their house bore the marks of William’s telescope-building.

William’s perfectionism paid off with the discovery of Uranus in 1781, and he was appointed King’s Astronomer to George III. Caroline received a salary as his assistant, making her the first professional female astronomer.

This 1800 letter from George III awards Caroline an annual salary of £50. It's on display in Cosmos & Culture. (Science Museum)

The Herschels moved to Slough, near the King at Windsor. Caroline had mixed feelings about this, as it meant giving up her musical career. But she threw herself into astronomical work. As well as assisting William, she discovered several comets and compiled catalogues of stars and nebulae.

Caroline discovered eight comets with her 'comet sweeper' telescope. (Science Museum)

Caroline also left an important legacy for historians of science. Her memoirs give an insight into the work of the Herschels and their counterparts, and also tell a lively human story. She describes having to force morsels of food into William’s mouth while he obsessively polished telescope mirrors for hours on end, and recounts a painful incident where she became impaled on the 40ft telescope.

William built this 7ft telescope for his sister. It's on display in Making the Modern World. (Science Museum)

If you want to find out more about Caroline I heartily recommend The Age of Wonder by Richard Holmes, or her own words in the autobiographies, edited by Michael Hoskin. Or you could visit the Herschels’ house in Bath, now a wonderful museum.