The Asteroid Threat!

The Asteroid Threat

Widnes SciBar - 11^th Nov 2015

 

Andy Newsam,  Professor of Astronomy Education and Engagement, Liverpool John Moores University.

Asteroids are small rocky objects orbiting the Sun. Although most asteroids in the Solar System are in the Asteroid belt between Mars and Jupiter, not all are restricted to it. Those not in the Belt could be a threat to Earth, as could those that are occasionally pulled out of that Belt by the gravity of Jupiter - these are called ‘Trogans’. As a result, there is a small possibility of one hitting the Earth but, if it did, the consequences could be massive. It is these ‘near Earth objects’ that astrophysicists are interested in. 

The craters peppering the Moon are a sign of how asteroids can come into the vicinity of the Earth - the age of these craters can be estimated from the amount of weathering that has taken place. There are far fewer known craters on the Earth but not all asteroid strikes will have left an identifiable crater - some will have landed in an ocean or vegetation may have obscured some craters on land.

An asteroid created the Barringer (or Meteor) Crater in Arizona about 50,000 years ago - the crater is about 1200 m across and 170 m deep. The asteroid was about 40 metres diameter - tiny as asteroids go. Such small asteroids are not yet detectable but that is not a great concern because the damage caused by them, whilst significant for many miles around, is not potentially

catastrophic for life on the Earth. 

Craters

In 2004 there was a ‘near miss’ when an asteroid of about 900 metres diameter passed between the Earth & Moon. If it had hit land on Earth it would have caused a crater about ‘the size of Wales’, throwing up a massive dust plume that would spread rapidly in the higher atmosphere and could block out sunlight and  so stop plant growth. Such an asteroid landing in an ocean would trigger a massive tsunami that would travel round the Earth. The Near Earth Asteroid Rendezvous (NEAR) space mission that landed on asteroid Eros in 2000 and the Rosetta Mission & its Philea probe landing on Comet 67P in 2014 have greatly increased the scientific understanding of asteroids. Previously, knowledge was limited largely to observing them from Earth and the evidence obtained from them hitting the Earth.

In brief, the risk of a large asteroid striking the Earth in our lifetime is small – they tend to occur about every 20 to 30 million years. However, the consequences of such a strike would be massive. Shown right is the Barringer Meteor/Crater in Arizona.

Andy described how scientists are seeking how to identify asteroids that pose a threat, how to track them and make them safe.

Detection. Most of the detecting work has now been done - it is believed that about 90% have been identified.

Liverpool Telescope, La Palma

Tracking. Tracking is currently the main focus of activity. It is being done by a combination of amateur observation (e.g. the privately run Spaceguard Centre in Mid-Wales) & large telescopes that are needed to track the smaller & more distant asteroids. Andy and his colleagues use Liverpool Telescope on the island of La Palma - it is the world’s largest fully robotic telescope, i.e. it can be operated from Liverpool. With such telescopes it is possible to pick out an asteroid from many stars by comparing images of the same area of sky taken some time apart - in contrast to the stars, an asteroid will have moved. Much of assessing is done by software but as it can only be relied upon to detect  95% of asteroids, the process isn’t perfect.

From these images, the course of an asteroid can be predicted for up to 100 years. If that suggests a danger to the Earth, the asteroid’s track will be kept under review - in time, a more accurate prediction of an asteroid’s risk can be made, often with a decision to remove it from the risk list.

As part of his ‘public engagement’ role, Andy spoke about involving children in identifying asteroids from two or more time-separated images from the Liverpool Telescope. A 12 year old spotted a faint trace that the professionals hadn’t noticed!

Making Safe. As yet we have no means of ‘making safe’ n asteroid heading our way. Use a nuclear bomb to blow them up? Apart from the practicalities of doing it, this could cause the Earth to be bombarded with broken lumps of the asteroid. Other possibilities include deflecting the asteroid’s path such as with the gravitational effect of a nearby massive weight (a ’gravity tractor) or painting one side white. If tracking identified a threat 20 years off, would there be the time & motivation to find a way to try to prevent a collision, to practice it & then to use it to make the Earth safe? 

Further Information

Andy is Director of the National Schools Observatory; ‘an online resource that brings the Universe  into the classroom’:- http://www.schoolsobservatory.org.uk/

Video of Andy actively engaging young people into science. Worth watching; Andy talks about finding asteroids from 42 minutes:- http://www.iop.org/resources/videos/education/schools-and-colleges-lecture/page_50047.html

Spaceguard Centre, Mid-Wales:- http://spaceguardcentre.com/

Bob Roach       30^th Nov 2015

Next Widnes Sci Bar Meeting and a Bonus

The next meeting of the Widnes SciBar will be on Wednesday 11th November at  7.30pm at the Hillcrest Hotel, Cronton Lane, Widnes.

Andy Newsam,  Professor of Astronomy Education and
Engagement at Liverpool John Moores University will discuss:

The Asteroid Threat

Asteroid impacts happen, but how big is the threat to humanity, what are we doing about it, and what more could or should we be doing? This is a debate the human race needs to have - and soon! Why not start here?

Presented by Friends of Catalyst & the Catalyst Science Discovery Centre

 

And an extra special treat for those who can make it:

 

2 pm at Catalyst Science Discovery Centre 

 

Professor David Southwood will draw on his 35 years of involvement with the European Space Agency to talk about:- 

 

Huygens & Rosetta Space Probes - Happy Landings

 

David will talk about his involvement in the Huygens probe launched in 1997 to Saturn’s moon Titan, landing in 2005 - the Rosetta probe launched in 2004 that resulted in the Philae lander landing on Comet 67P in 2014.

Entry to the talk will be free - access to the lecture theatre is up the staircase near the entrance. Whilst at Catalyst you can also visit:-

 

The Mersey Gateway Visitor Centre to find out about the construction of the new bridge over the Mersey & related approach roads - entrance to the exhibition is free,

 

The Catalyst Science Discovery Centre exhibition areas - charges apply:- 

 

http://www.catalyst.org.uk

 

Hans Krebs, from Hildesheim to Sheffield

The Widnes Sci Bar provided an opportunity for me to try out my talk on Sir Hans Krebs from a wider historical perspective as well as trying to communicate the impact of his work. As usual, the audience was good in number and searching in questioning, after the drinks break! It is really rewarding to talk to a group who have such a range of life experiences and who can call up memories of school, university and science from the work place. The talk included a few items to demonstrate the changes in technology associated with Biochemical research: from the Warburg flask to the fluidic microchip which stirred up a few memories of the craftsmanship of the scientific glass blower for some. Following last night's talk, which is provided as a presentation labelled Krebs Talk (on the right hand side-bar), I have provided some of the requested information at the foot of this post. This includes a summary of the knowledge base in metabolism at the turn of the 20th Century, from my undergraduate Blog site, together with a set of links relating to ATP and energy production in the mitochondria and in relation to photosynthesis. The body of the post summarises some of the main points from the talk and includes selected images (all of which are in the attached power point show). 

Hans Krebs was born in Hildesheim, north Germany in the first year of the 20th Century: his father Georg was a surgeon and his mother was Alma Davidson. Hans attended the local grammar school and subsequently studied medicine medicine at a range of University locations including Göttingen, Freiburg-im-Breisgau, Hamburg and Berlin, where he eventually joined the laboratory of Professor Otto Warburg. Warburg (right) was both a technical and intellectual genius; and in his laboratory, Krebs acquired the cutting edge experimental techniques of the era and soon developed a keen interest in the major biochemical challenges of the day. Key to the work that Krebs was to pursue first at Freiburg (1930-33), then Cambridge (1933-5) and finally at Sheffield (1935-1954), which would lead to the Nobel Prize in 1953, was the Warburg flask and manometer. This device enabled Krebs (and most Biochemists of the day), to make careful measurements of carbon dioxide release and oxygen uptake, by thinly sliced tissues incubated with a range of carefully controlled metabolites and inhibitors. 

In 1937, in association with William Arthur Johnson, a PhD student in the laboratory (you can read a nice appraisal of Johnson here, by my colleague at Sheffield, Milton Wainwright), Krebs published a manuscript entitled 

"The role of citric acid in intermediate metabolism in animal tissues" (1937) Enzymologia 4 148-156. Krebs H.A. and Johnson, W.A.

A summary of his work in the context of the field is available as a transcript of his Nobel Lecture as a pdf here. The original manuscript was rejected by the journal Nature, through an apparent lack of space! Krebs immediately submitted his findings to Enzymologia and rapid publication ensued. The Krebs cycle is also referred to as the citric acid cycle or the tri-carboxylic acid cycle (TCA for short) and occupies a central position in the metabolic "circuitry" of the cell. The image below (which a number of the audience were keen to obtain a large format print!) gives some indication of the incredible complexity of metabolic pathways, much of which would not have been unlocked without the incredible experimental insight brought by the work of Hans Krebs. (I came across this Blog site where those of you who wish to try and obtain a printable file can contact the Blogger).


I realise that the resolution is too poor for a detailed analysis, but it does create quite an impression!

The problem that followed on from the Krebs Cycle, was how do the products generate energy in the form of adenosine triphosphate (ATP). It was clear from the questions that this was of interest to many of the audience, so here is a summary of my response to the questions and some links to further reading.

The "products" of the Krebs Cycle are carbon dioxide (waste) and importantly "reducing power" in the form of NADH and FADH. The electrons that are conducted along a series of electron carriers associated with the inner membrane of the mitochondria, are punctuated by a series of large rotary enzymes that harness the differences between the proton concentration on the inner an outer face of the membrane to catalyse ATP synthesis from ADP and inorganic phosphate. You can read about NAD and the enzyme that finally catalyses the synthesis of ATP by following the links to a series called molecule(s) of the month. As I said, it was a radical rethink of methods and aspects of physical chemistry that led Peter Mitchell to propose the chemiosmotic theory of ATP synthesis. This had a bumpy ride at first with most "old school" Biochemists, but the subsequent joint award of the Nobel Prize for Chemistry in 1997 to Sir John Walker (Cambridge) and Paul Boyer (USA) gave a molecular basis for the Mitchell hypothesis. The MRC website has some animations  and this youtube movie is breathtaking! I hope it explains the phenomena better than my hand-waving!

Finally, for those of you who want to read more about photosynthesis, there are the usual wiki links, but you might like to look at Neil Hunter's web site, a colleague of mine at Sheffield who was awarded an FRS for his work on bacterial photosynthesis a few years ago. There are some powerful new microscopy techniques that are beginning to provide molecular insight into the molecules in vivo and I recently attended a lecture by the Baumeister group from the Max Planck Institute in Munich. The images on the left are visualisations of the thylakoid stacks that form the structural support for the light harvesting complexes that feet photons into the chloroplasts and the photosystem which runs alongside the fixation of carbon dioxide into a reaction catalysed by the most abundant enzyme on the planet Ribulose Bisphosphate Carboxylase, or RUBISCO! 

I hope this provides a helpful addition to the talk material and any comments are most welcome. You can also read more about the Sheffield Krebs Fest in this pdf version of the small brochure I passed around.

Symmetry is the key to everything Widnes SciBar, 9th Sept 2015

 Symmetry is the key to everything

Peter Rowlands

Honorary Teaching Fellow

Department of Physics, 

Liverpool University

Peter said that his interest in the history of science leads him to believe the conventional teaching of physics is not the source of the deepest creativity in physics and that this is part of the reason why there has been no really new ideas at the fundamental level since the appearance of the Standard Model over 40 years ago. Whilst it continues to be widely accepted, with numerous experiments since then verifying it, there has been no progress in explaining this theory. Many efforts to do so have involved ‘string theory’ despite the fact that such an ‘explanation’ is more complicated than what it seeks to explain.

When Peter did his Phd, he designed and built his own apparatus for carrying out his research project, and computers had little relevance - he recalled they were so primitive he could work out his calculations easier by hand.

In contrast, the Phd student in high energy physics today has little contact with setting up the apparatus - that is done by large design teams and specialist engineers working to specifications prepared by lead scientists. A student will often spend a year working in shifts at a laboratory such as CERN monitoring the experiment from a control room. They have access to huge stores of data on which they perform endless computer analyses. Before any results are published they are subject to significant internal scrutiny.

Peter doesn’t work like this. He doesn’t use computers and ‘work’ for him involves thinking, writing and discussing. ‘I don’t work away at the same problem, I wait until something creates link in my brain’. He is interested in the big questions & in using a more philosophical approach than is normal for physicists.

Climb the Mountain or Cross the Valley?

Lee Smolin, an American physicist, suggested there are two types of scientist. Most scientists are ‘mountain climbers’ who work in a particular area of their science throughout their career and gradually attain a summit of perfection. Much less in number, ‘valley crossers’ look for connections between different areas. Peter is a ‘valley crosser’ and, he believes, the really major breakthroughs nearly always involve ‘valley crossing’.

For example, Isaac Newton stands out from other physicists of the past in that he described the seemingly intangible world of the falling apple in totally abstract ways. In so doing, he defined mass on the same basis as time and space. He thought outside the paradigm (or the conventional thinking), but not contradictory to it.

Peter recalled that at the age of 12, rather than playing with Meccano, he played around with mathematical equations, such as those from Einstein’s Special Relativity theory. He noticed that if he kept increasing the speed of light, mass became imaginary - his first ‘discovery’. This was an early example of his desire to find out what happens if you theoretically push things to extremes.

Whilst Peter’s first interest was in using maths to get to the most fundamental laws, he realised that physics was the setting where he could do this. From an early stage he thought that symmetry was the key to making breakthroughs and his talk was about the results of a very long term personal and unique project in this area. Currently his proposals are seen as ’interesting’ by other physicists but they could become an alternative to the Standard Model if confidence in it fades, e.g. due to results from the Large Hadron Collider not supporting it.

Example of Symmetry in Particle Physics

Symmetry is everywhere in physics, especially in particle physics. For example, being negative the electronic charge has the characteristics of an imaginary mass. Similarly, in relativity, time behaves as though it is an imaginary dimension of space - there is some kind of symmetry there and it must be there for a reason! Peter proceeded to present his theories but as this involved complex mathematics, this is far enough for now! As commented by one of those present, ‘I found his mathematics and matrices a bit beyond my immediate comprehension although I could see how it had resulted in a mathematically beautiful result. Whether this symmetry analysis is a true representation of nature remains to be seen, but I am tempted to hope so.’ 
 

Bob Roach

roach36@talktalk.net

23rd September 2015

Andrew Davies- A Brief History of Astro-Photography June Sci Bar

Last month's Sci Bar presentation was delivered by Andrew Davies, a passionately enthusiastic amateur astronomer, who took the audience down a fascinating journey into the history and skills of astro-astronomy. Andrew introduced himself as a former teacher who appears to have managed to turn his hobby into an incredibly rewarding and successful community service. With his partner, Sue, and support from the local authorities and a range of organisations, he described his approach to educating young adults from some of the most challenging communities through astronomy. You can read more about the work of the Knowledge Observatory by following the link (that's Sue and Andrew top left). However, as Andrew pointed out, by the time I post this, the Observatory will have relocated from Wigg Island (a Nature reserve that has risen from the ashes of a copper factory, having a wartime association with mustard gas production!), to what promises to be a new "mecca" for astronomers which can be viewed at the Astrofarm Facebook site. 

Andrew began his presentation (which thoughtfully incorporated a drinks interval!) with the story of his serendipitous find on a market stall some years ago:  a box of "magic lantern" slides. Already fascinated with the moon and stars as a youngster, the first part of Andrew's talk took us back to the pioneering days of photography, telescopy and of course astronomy, which like much of Victorian Science was the pursuit of the wealthy gentlemen. Andrew stressed the parallel development of photography itself with that of  astronomical telescopes. Names including Henry Fox Talbot (HFT) who would file and defend many patents relating to the chemistry of reproduction (see the famous long exposure calotype, top right, in which HFT appears in several positions in the same scene!). 

Using the images from his "prized" magic lantern collection, Andrew gave us a whistle stop tour of the instruments that have provided us with some of the earliest images of the planets, their moons and the more familiar features of the "heavens". Most of the early slides were actually drawings transferred onto the glass slides taken from observations on telescopes The telescope shown right was famously assembled by William Parsons York, the third Earl of Rosse. What I liked was Andrew's side by side comparison of early images with some of his own photographs. Andrew was at pains to point out the amazing quality of some of these historic observations despite the clockwork mechanisms of the telescopes, compared with modern electronic tracking technology.  

Andrew introduced us next to the systematic and scientific approaches to astrophotography practised for example by E.E. Barnard who used the University of Chicago's 40" telescope at the Yerke's Observatory to produce early high resolution images of the milky way, comets (LHS), eclipses etc. Again, Andrew used the comparative images from "then and now" to share his enthusiasm and respect for these early pioneers of astrophotography. I was impressed by the extraordinary expert knowledge of the Widnes SciBar audience who were able to identify many astronomical landmarks from Andrew's slide show!

The second half of Andrew's presentation included detailed insights into the tricks of the trade and he showed many breathtaking images of the moon, sun spot phenomena, and much much more: I couldn't possibly do justice to Andrew's enthusiasm, knowledge and the beauty of his images. However, I hope I have managed to convey the impression of an evening fuelled by passion and enthusiasm for astronomy and I wish him and Sue well in their new venture in France. Our loss of his energy and commitment to the Knowledge Observatory will surely be Limoges' gain!