Category Archives: Astronomy

Einstein’s unfinished symphony in the media

Our recent discovery of an unpublished model of the cosmos by Albert Einstein (see last post or here for a preprint of our paper) is receiving a lot of media attention, it’s very humbling. First off the mark was Davide Castelvecchi with a very nice article in Nature. Davide’s article was quickly reproduced in various outlets, from Scientific American here to the Huffington Post here. Trawling over the internet, I see newspaper and magazine articles describing our discovery in a dozen languages. It’s nice to see historical material receiving this sort of attention, I guess everyone loves an Einstein story.

einsteinjpgjpg-4a389e85f92a0547

I’m also intrigued that it was the traditional media that picked up the story – with the exception of Peter Woit, no-one in the blogosphere seemed to notice our preprint or even a blogpost I wrote describing our paper. Perhaps we bloggers need the imprimateur of respected print journals more than we care to admit!

I notice one slightly misleading point in the electronic version of the Nature article is getting repeated everywhere. It’s probably not quite correct to frame Einstein’s attempt at a steady-state model of the cosmos in terms of a resistance to ‘big bang’ theories; there is no reference to the problem of origins in Einstein’s manuscript. Indeed, one of the most interesting aspects of the manuscript is that it appears to have been written in early 1931, at a time when the first tentative astronomical evidence for an expanding universe was emerging but the issue of an explosive beginning for the cosmos had yet to come into focus (e.g. the great debate between Eddington and Lemaitre later in 1931). It’s interesting that the initial mention in Nature of resistance to ‘big bang’ theories  is repeated in almost all other outlets, one can’t help wondering how many science journalists read our abstract. An honorable exception here is John Farrell at Forbes Magazine. John certainly noticed the discrepancy and no wonder – John has written an excellent book on Lemaitre.

index

All in all, it’s been a lot of fun so far. I’m getting quite a few emails from distinguished colleagues pointing out that Einstein’s model is trivial because it didn’t work, which is of course true. However, our view is that what Einstein is trying to do is very interesting from a philosophical point of view  – and what is even more interesting is that he apparently abandoned the project when he realised that a consistent steady-state model would require an amendment to the field equations. In short, it seems the Great Master conducted an internal debate between steady-state and evolving models of the cosmos decades before the rest of the community…

Update

There is a very nice video describing our discovery here.

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Filed under Astronomy, Cosmology (general), History and philosophy of science

VM Slipher and the expanding universe

In an earlier post, I mentioned an upcoming  conference in Arizona to celebrate the pioneering work of the American astronomer Vesto Slipher. As mentioned previously, 2012 marks the centenary of Slipher’s observation that light from the Andromeda nebula was Doppler shifted, a finding he interpreted as evidence of a radial velocity for the nebula. By 1917, he had established that the light from many of the distant nebulae is redshifted, i.e. shifted to lower frequency than normal. This was the first  indication that the most distant objects in the sky are moving away at significant speed, and it was an important step on the way to the discovery of the expanding universe.

Vesto Melvin Slipher (1875-1969)

The conference turned out to be very informative and enjoyable, with lots of interesting presentations from astronomers, historians and science writers. It’s hard to pick out particular talks from such a great lineup, but three highlights for me were Einstein, Eddington and the 1919 Eclipse Expedition by Peter Coles, Georges Lemaitre: A Personal Profile by John Farrell and Slipher’s redshifts as support for de Sitter’s universe? by Harry Nussbaumer. The latter compared the importance of the contributions of Slipher, Hubble, Einstein, De Sitter, Friedmann and Lemaitre (to mention but a few) and was a focal point for the conference. My own talk ‘Who discovered the expanding universe? – an open bus tour’ was quite similar to Harry’s , with some philosophy of science thrown in, while Micheal Way’s talk Dismantling Hubble’s Legacy? also touched on similar ground.  However, there was little danger of overlap since viewpoints and conclusions drawn from the material varied quite widely! You can see the conference program here.

A slide from Peter Cole’s talk on the Eddington eclipse experiment

A slide from John Farrell’s talk showing a postcard from Lemaitre to Slipher, announcing the former’s visit to the Lowell observatory

Harr Nussbaumer, author of ‘The Discovery of the Expanding Universe’,  in action

Front slide of my own presentation

The best aspect of the conference was the question and answer session after each talk. There was quite a divergence of opinion amongst the delegates concerning the relative importance of the various scientists in the story, which made for great discussions (though I suspect that much of the argument arises from differing views concerning the role of the theoretician vs the role of the experimentalist). You can see a list of speakers and abstracts for the talks here and the slides for my own talk are here.

There was plenty of material here for the relativist; indeed, quite a bit of discussion concerned the relative contributions of Friedmann and Lemaitre (told you it was a good conference). In particular, the Israeli mathematician Ari Belenkiy gave a defence of Friedmann’s work in his talk Alexander Friedmann and the Origin of Modern Cosmology, pointing out that the common assertion that Friedmann took no interest in practical matters is simply untrue, given his work in meteorology, and that the relevant astronomical data was not widely available to Europeans at the time. I must admit I share Ari’s view to some extent; I’m always somewhat in awe of a theoretician who describes all possible solutions to a problem (in this case the universe), as opposed to one solution that seems to chime with experiments of the day.

Title slide of Ari’s talk on Friedmann

The conference also included a trip to the Lowell observatory, including a view of the spectrograph used by Slipher for his groundbreaking measurements and a peep through the famous 24-inch Clark telescope which remains in operation to this day. We were also treated to a few scenes from Dava Sobel’s upcoming play based on her book on Copernicus, read by Dava herself and the eminent Harvard science historian Owen Gingerich.

The famous spectograph, perfectly preserved

Slipher’s telescope remains in use today

Dava Sobel and Professor Owen Gingerich reading from her new play at the Lowell observatory

All in all, a superb conference, definitely worth the long trip (Dublin-Chicago-Phoenix-Flagstaff). Earlier in the week, I gave a longer version of my talk at the BEYOND centre at Arizona State University in Phoenix; I was afraid some of the theoreticians in Larry Krauss’s  group might find it a bit equation-free, but they seemed to enjoy it. Larry and Paul Davies have a fantastic operation going on at the BEYOND centre, but I have to say the ambience and surroundings  at Flagstaff are probably more suitable for a European – much nicer weather!

Many thanks to Ari Belenkiy for the photographs. You can find more descriptions of the conference on John Farrell’s Forbes blog, and on Peter Coles’s  In The Dark blog.

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September conference: origins of the expanding universe

A conference next month will celebrate the pioneering work of the American astronomer Vesto Slipher. On September 13-15th, the Lowell Observatory in Flagstaff, Arizona, will host the conference The Origins of the Expanding Universe to commemmorate the hundredth anniversary of Slipher’s measurements of the motion of the distant nebulae; see here for the conference website.

As readers of this blog will know, Slipher observed that the light from many of the distant nebulae was redshifted, i.e. shifted to lower frequency than normal. This was the first  indication that the distant nebulae are moving away at significant speed and it was an important hint that some nebulae are in fact distinct galaxies far beyond our own Milky Way (see cosmology 101 section). A few years later, Edwin Hubble combined Slipher’s redshift results with his own measurements of distance to establish that there is a linear relation between the distance to a galaxy and its rate of recession; the relation became known as Hubble’s law although it probably should be called the Hubble/Slipher law.

The Hubble/Slipher discovery of the recession of the galaxies  was a key step along the road to the discovery of the expanding universe, but the two are not quite the same thing; for the latter, one needs to situate the phenomenon in the context of the general theory of relativity (according to relativity, the galaxies appear to be moving away from one another because space is expanding). The Belgian physicist Georges Lemaitre was the first to make the connection between the relativistic universe and the observed recession of the galaxies, although his contribution is often overlooked. A major thrust of the conference is to explore exactly such distinctions; looking at the lineup, it looks like an intriguing mixture of cosmologists, astronomers and historians.

All this is highly relevant to my yet-to-be-completed book so after a long, wet summer at WIT, I’m off to sunny Arizona next month!  My own talk is titled ‘Who discovered the expanding universe?’ and I intend to compare and contrast the contributions of various pioneers such as Slipher, Hubble, Humason, Friedmann and Lemaitre. You can see a list of speakers and abstracts for the talks here.

Many thanks to Peter Coles of In the Dark for drawing the conference to my attention.

Update

Going on holiday just as classes start back? Nice job – Ed.

Sigh. I haven’t had a day off all summer and this is not a holiday.

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Filed under Astronomy, Cosmology (general), Third level

A letter to the Minister for Education

On Friday evening, I gave a public talk on the big bang at Blackrock Castle in Cork. I always enjoy giving public science talks, but this one was special (slides here). The venue was a beautiful castle overlooking the sea and I was enormously impressed with the science outreach work being done there by Dr Niall Smith, director of research at Cork Institute of Technology. I was equally impressed with the new observatory at the castle and the astronomy program of Niall and his postgraduate students. Superb work in a fantastic location, surely an inspiration for generations of young students.

Blackrock Castle in Cork: the white dome above the tower is the observatory

I left Cork early on Saturday morning in order to travel to Dublin to catch the High Flyers conference of the Institute of Physics (this is what physicists get up to on bank holiday weekends!). On my way to the meeting, I heard the Irish Minister for Education interviewed on RTE Radio One (Marian Finucane show, May 5th). The Minister had many interesting things to say on subjects such as RTE, the Catholic Church, a recent libel case in Ireland and the near-paralysis of political process in the United States (the latter is a most unusual topic for a politician over here). However, I was taken aback to hear him refer to “problems of productivity in the third level sector, particularly in the Institutes of Technology”, and disappointed that the interviewer didn’t seek some clarification on the comment.

I would very much like to know what the Minister meant by this comment. What do we understand by ‘productivity’ in the context of the third level education? How is it measured? Is it the number of students taught? Number of Noble prizes for research?  Perhaps some Soviet-style quota of engineers graduated? Like all Institute lecturers, I have a heavy teaching load; we produce legions of exactly the sort of science, computing and engineering graduates that Ireland so desperately needs. I must say I grow weary of generalizations like this about third level academics from journalists and politicians, and such a comment from the top man in education is pretty serious. Not a scintilla of evidence was offered by the Minister in support of his remark, just a casually delivered public insult to my colleagues and I.

Here’s the thing, Minister Quinn: like almost all lecturers in the Institutes of Technology (IoTs), I teach between four and five different courses per semester to degree level, a larger teaching load than any third level college in the world as far as I know; add research and outreach activity to this and it is no surprise I am in the office until 9 pm at least four days a week. In terms of prep, each semester typically presents at least one new module to teach, involving months of preparation over the summer, where I would hope to be concentrating on research, finishing my book and attending conferences. (I teach diverse courses in mathematics and physics to students in the departments of computing, engineering and science, not to mention more specialized modules in quantum physics, cosmology and particle physics – how many Harvard professors can boast such a wide teaching portfolio?).

‘Yes, but what about other IoT lecturers?’, the Minister will ask. I imagine I have a more accurate view of the work of my colleagues than the Minister’s advisors and I have no complaints. Indeed, the limited time I have for research arises because other lecturers take on the bulk of student administration (the large number of classes in the IoTs necessitates a great deal of admin; Year Tutors and Course Leaders spend a great deal of time keeping track of attendance, assessments, lab performance  and exam results). There are no easy lecturing jobs.

I love my job and stopped counting the overtime years ago. However, it is frustrating to hear the work of lecturers in the institutes and the universities denigrated by politicians who know nothing of what we do. The tragedy is, I suspect the binary system of universities and institutes has served Ireland very well, although few in charge of education seem to realize it. As they consider the future of the third level sector, I hope politicians and their advisors will make an effort to understand the current system, rather than indulge in unsupported generalizations.

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Astronomy and cosmology at Birr Castle

Yesterday, I travelled to historic Birr Castle in the centre of Ireland in order to catch the end of the annual meeting of the Astronomical Science Group of Ireland. Birr Castle is a great setting for an astronomy meeting –  not only is it a beautiful castle with fantastic grounds, it is also an important landmark in the history of astronomy. The castle was the home of the famous Leviathan, a reflecting telescope that was the largest instrument of its kind in the world for many years. The telescope was built in the 1840s by Lord Parsons, the third Earl of Rosse, and featured  a 72-inch mirror, a marvel of engineering at the time.  He made many important discoveries with the instrument, not least the first observation of the spiral structure of some of the distant nebulae and the detection of stars within the nebulae. Indeed, the Earl was one of the first to propose that the nebulae were entire galaxies distinct from our own, a hypothesis that was not definitely established until Hubble’s measurements with the 100-inch Hooker telescope at Mt Wilson in California.

Birr Castle in Co.Offaly

The Leviathan telescope at Birr castle

There were a great many interesting talks over the two days of the meeting (see program here), but I was there to catch ‘The Search for Polarization Fluctuations in the Cosmic Microwave Background’ by Creidhe O’Sullivan of NUI Maynooth. Creidhe started with a basic overview of the cosmic microwave background (CMB), explaining its importance as evidence in support of the big bang model and describing the measurements of temperature fluctuations in the radiation by the COBE and WMAP satellites. (The CMB is the primordial radiation left over from the time that atoms first began to form. Cosmologists and astronomers spend a great deal of time studying the tiny temperature fluctuations imprinted in the CMB, as this gives information on the density and geometry of the early universe, see the Cosmology 101 section of this blog.)

Creidhe then moved on to explain the study of polarization in the background radiation. The CMB radiation is expected to be polarized because it comprises light that has been scattered by many particles; when light is scattered, it gets polarized into different planes of vibration. (Polaroid sunglasses operate on the same principle; they cut down on light by allowing only light polarised in one plane to pass through). Hence cosmologists search for fluctuations in polarization as well as temperature in the CMB, although the polarization fluctuations are much smaller. Mathematically speaking, the polarization is divided into two modes: electric (E –mode) and magnetic (B-mode) polarisation. E-modes have been detected since 2003; the analysis of these modes has become a major area of research in cosmology. Creidhe gave a superb overview of the instruments used to analyse the E- modes, including the work of her own group with the QuaD experiment at the South Pole.

The QUaD experiment at the South Pole

She finished the talk by explaining that the next big challenge in cosmology is the detection of B–mode polarization in the background radiation. B-modes present a great challenge as they are yet more difficult to detect. The great hope here is that the PlANCK satellite telescope, with its improved resolution. Just as the COBE satellite results were a watershed in our view of the early universe, the resolution of B-mode polarization in the CMB by PLANCK would give yet more support for the big bang model and cosmic inflation, and even offer evidence for the existence of gravity waves.

The Planck satellite telescope

That is not to say terrestrial experiments will not have their place. After Creidhe’s talk, another member of the Maynooth group, Stephen Scully, gave a brief overview of the team’s work on the QUBIC experiment. This is a new type of the bolometric interferometer that will be used in the next generation of terrestrial measurements at the South Pole.

All in all, a most informative afternoon. After the talks, we were shown the site in the castle grounds where a new radiotelescope is to be situated. This will form the Irish node of the international LOFAR astronomy project, bringing Birr castle up to date with modern astronomy – more on this in the next post.

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How it ends

This month’s issue of Physics World features a review of mine, of the book How It Ends by astronomer Chris Impey. I’m always chuffed to be published in Physics World; as the flagship publication of the Institute of Physics it is a very good science magazine indeed, with well-informed commentary and articles of very high level by prominent researchers. PW also take their book reviews seriously; I notice both the front cover and editorial of this issue draw attention to the reviews.


As for the book: I enjoyed How It Ends greatly, it’s a fabulous read for any scientist or anyone with even a marginal interest in science. In a nutshell, Impey, a noted astronomer and astrobiologist, considers the ultimate fate of all things, from the future of the planet and all living things to the fate of the sun, the galaxies and the entire universe. As you can imagine, the book traverses a great many disciplines, from biology, biochemistry and ecology to geophysics, astrophysics and cosmology. However, it is written in a very lighthearted and accessible style that is extremely readable. PW magazine is members-only but you can read my review here….or better still go and buy the book.

Actually, the skill with which Impey handles his interdisciplinary tale is no coinicidence as he is associated with a well-known research group at Arizona State University  that specializes in astrobiology, a discipline that combines the very different disciplines of astrophysics and biology in order to investigate the conditions necessary for biological life to form. In fact, members of the Arizona group had some input into the major success in astrobiology we all just heard about- the discovery of lifeforms that can thrive on arsenic (as opposed to phosphorous), an important advance that broadens the scope for the possibility of life existing elsewhere.

So go and buy the book.

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Astronomy Ireland and IYA

Last Saturday, Astronomy Ireland hosted an extraordinary national meeting at the Science Gallery at Trinity College Dublin, in order to draw members’ attention to planned events to mark the UN International Year of Astronomy.

Astronomy Ireland (AI) is Ireland’s premier astronomy club and it promotes astronomy, space interest and science education all over the country. I first became aware of the club when I attended some great cosmology talks they hosted last year (see post on a lecture onThe Cosmological Distance Ladder by Micheal Rowan-Robinson here and on Dark Matter by Tim Sumner here); AI also organise observing sessions and other astronomy events nationwide, not to mention running astronomy classes in various institutions around the country. I attended their astronomy classes in our own college this semester and found them excellent (well done Emmet Mordaunt!).

Saturday’s meeting offered a packed program of talks, short films and discussions. First up was film producer and director Ginita Jimenez of film company Father Films, who described how she came to make a short film about Venetia Phair, the 11-year old Oxford schoolgirl who named the planet Pluto. I missed the beginning of Ginita’s talk, but her description of reading a short newspaper article on the topic and her subsequent discovery that Venetia had never actually seen the planet, was fascinating: with the demotion of Pluto to ‘dwarf planet’ status, she knew she had to make a film about the whole affair.

After Ginita’s introduction, we were treated to the Irish premiere of ‘Naming Pluto’. Sure enough, it was a beautiful little film: the discovery of a new planet from the perturbations in the orbit of Uranus, the naming of the planet by Venetia, granddaughter of Falconer Madan, ex-Head of Oxford University’s Bodleian Library, the subsequent passing of the name to the powers that be in Flagstaff USA, it was all there. (I’m not sure how many of our students would have 11-year old Venetia’s knowledge of both astronomy and classical mythology – planets are generally named after Roman gods and Venetia suggested Pluto as he is the Roman god of the underworld). The second part of the film described an older Venetia’s visit to uber-astronomer Patrick Moore, a failed sighting, and then her first sighting of the planet she named all those years ago at the Science Observatory in Hertsmonceaux at age 89. The film finished with some moving shots of an aged Venetia telling her story to a group of wide-eyed students – straight out of C.S. Lewis, you could see them trying to imagine her as an 11-year old! If you want to know more, there is a summary of the story here and a nice trailer of the film on YouTube here; better still, why don’t you buy the film here.  

Robert Hill of the Armagh Planetarium and Northern Ireland Space Office then gave a lively overview of activities worldwide that are taking place to mark the International Year of Astronomy. The sort of activities involved are:

100 hours of astronomy: a round-the-clock event that features live webcasts from research observatories around the world

The Galileoscope ; the distribution of thousands of easy-to-assemble, easy-to-use telescopes to budding astronomers around the world: each telescope has about the same power as that available to Galileo

Cosmic Diary: an astronomy blog featuring regular posts by diverse professional astronomers

Portal to the universe; a one-stop web portal for astronomy that will feature astronomy content, acting as an index for press, educators and scientists

Dark Skies Awareness: a project promoting the awareness of light pollution

It was a great talk and you can find out more about the various activites on the IYA website.

AI founder and chairman David Moore also gave a talk, describing the activites of Astronomy Ireland for the year that’s in it, in particular the school lecture program and the teacher training program. He also described what individual members could do, from voluntary work to lobbying public representatives. A change of mission was highlighted: instead of confining itself to promoting astronomy, David sees AI as promoting a science culture in Ireland. He pointed out that while Ireland has a great culture in both arts and sports, it has no such culture in science, despite a great heritage in the subject. I think he is absolutely right in this and it strikes me that astronomy is a very good place to start to address the problem..you can find a list of the planned AI activities here or on the AI website.

David Moore (R) in interview at the Young Scientist Exhibition

After David’s talk, we were treated to another short film. 3-d glasses were handed out and Robert Hill presented a short spectroscopic tour of the universe. I won’t attempt to summarize the film, but there were some stunning graphics. You can get a flavour of it by taking the tour on the website of Celestia. As usual, I came away thinking just how insignificant our own little galaxy is in the wider scheme of things.

All in all, the meeting was a lively and informative event, with a serious mission behind it. Afterwards, we left the beautiful Science Gallery for some hot food and drinks at the pub across the road (it was an Irish meeting after all). There, discussions on the promotion of science continued for many hours…

Update:

I just heard from Ginita that Venetia died last week at the age of 90. Sad news, but I’m sure she enjoyed seeing the film in her final days. You can find a nice NYT obituary here. Ar dheis De do raibh a h-anam

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ESA Mission to Mars

This week is Engineering Week in Ireland and it got off to a great start at WIT with a talk on space exploration at the European Space Agency (ESA) by Micheal McKay, the Belfast-born engineer who has acted as Flight Operations Director for ESA lunar and Mars missions. (The seminar was presented by CALMAST, the Centre for the Advancement of Learning of Mathematics, Science and Technology at WIT, see here for other science/engineering events this week).

Dr McKay started with a superb outline of space exploration in general and of the work of the European Space Agency in particular. He put great emphasis on practical applications such as:

- the monitoring of the earth’s climate via the ESA ERS satellites:

- the forthcoming ESA Galileo GPS network, an independent European satellite telecommuncations network, vital for air traffic contol and for air/sea rescue:

- the SOHO mission, a study of the interaction of solar output with the earth’s magnetic field with the ESA SOHO satellite:

- observations of the most distant galaxies using Far Object Cameras mounted on ESA satellities:

- the study of the atmosphere of Venus using an ESA satellite, gathering vital information on the greenhouse effect and its implications for the earth.

One of the ESA’s earth-monitoring satellites

A schematic of the ESA’s Galileo GPS system

McKay then went on to talk about the ESA’s greatest success – the Mars Express Orbiter. He gave a superb overview of the information got from the orbiter, despite the loss of the Beagle II Lander. Indeed, McKay spent a good deal of time on the Mars mission, explaining carefully that it was the Mars Express that established the first firm evidence for substantial ice/water at the south pole. At this point, the speaker described two great examples of the sort of thinking-outside-the box engineering solutions  necessary in his  job  – the slow rotation of the Mars orbiter into sunlight to free up a jammed hinge on one of the antennae, and a software ‘sunglasses’ patch to protect a sensitive detector from excess sun…both successfully completed from hundreds of millions of miles away!

The Mars Express Orbiter

McKay also spent some time explaining the next ESA Mars project, a  manned mission to Mars in 2030.  I won’t describe this part in detail, but you can find details of the Aurora mission here;

This ws a fine seminar and there were a few general themes  I liked a lot:

(i) ‘you too can do this’ – like so many at the top, the speaker continually emphasised to the students that they too had the potential for a great career in space exploration

(ii) the outstanding success of a relatively young European space agency (currently accounts for 40% of the global space market) and the fact that European citizens are not always aware of it

(iii) the spectacular benefits of European co-operation, and of the co-operation between ESA and NASA and other space agencies – nations seem to co-operate better in space than down here!

(iv) the importance of space exploration in its own terms for our knowlege of our universe, plus the beneficial spinoffs such as the ERS  earth observation missions

(v) the success of Ireland’s membership of ESA: not just in terms of commercial contracts gained, but the payback in terms of experience and knowledge brought back to Ireland, and the potential for fantastic careers in space exploration for the next generation of Irish science and engineering students

Interesting that many of these themes are precisely the advantages that I, and others, refer to as the potential benefits of Irish membership of CERN – see earlier post on CERN and Ireland.

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At question time, I asked the speaker the stock question – given the expense of building the space station necessary for manned expeditions to Mars, what can a manned mission discover that robotics cannot? He answered this in detail, carefully listing the problems of communication and contol of robots. It will be interesting to see what happens in the context of the current recession..

All in all, this was an inspiring seminar for our students given by a top expert in the field.  For me, the highlights were a music video showing the docking of the ESA vessel Columbus to the International Space Station, and the description of the solutions to engineering problems with the Mars Express orbiter – from a software patch to protect a detector from excess sun, to the rotation of the station into sunlight to free up a jammed hinge!

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