Natural Sciences


Peter DavidsonBy Peter Davidson, Senior Curator of Mineralogy Comets are very much in the news at the moment with the approach of the European Space Agency’s (ESA) probe “Rosetta” to the comet called 67P/Churyumov-Gerasimenko (I know it is a bit of a mouthful so let’s call it 67P/CG for short). The hope is that Rosetta will be able to land on the comet and take sample and readings to send back to scientists on Earth. 67P/CG is a regular visitor to our part of the Solar System orbiting the Sun every 6½ years.

Comet 67P

Comet 67P/Churyumov-Gerasimenko. Image Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Comets are truly one of the wonders of the Solar System. Unlike asteroids, they are not solid but composed of a mishmash of varying quantities of rock fragments, dust and ice (a comet is sometimes referred to as a “dirty snowball”) and can come in a range of sizes from a few hundred metres to tens of kilometres. Some comets are thought to originate in an area just beyond our Solar System called the Kuiper Belt, a region of cold, icy bodies, others are thought to derive from the Oort Cloud which lies even further out, beyond the Kuiper Belt. But the most distinctive feature of a comet is of course its tail. The tail isn’t there all the time and appears only as the comet approaches the Sun. The heat from our star causes the ice to vapourise and stream out from the main body carried by the solar wind. It contains not just ice, but small dust and rock particles and can stretch many millions of kilometres and is very spectacular when visible from Earth. Once the comet has passed, the tail, or rather the rock and ice particles that make up the tail, remain where they were left, and this fact is important to our story. One thing we might notice about comets is that the tail of a comet always points away from the Sun. So when the comet reappears from behind the Sun, the tail will be in front of the comet and not behind it.

Comet Hale-Bopp with its tail

Comet Hale-Bopp with its tail. Photo by NASA.

The orbit of a comet round the Sun

The orbit of a comet round the Sun. Image Hong Kong University.

One of the most famous of all comets is called Halley’s or 1P/Halley to give it its proper name (tip: the name of this comet is pronounced in one of two ways, 1) like Hal the male first name, thus hal-ley or 2. Like hall, thus hall-ley. But definitely not like hail).1P/Halley was named after the astronomer Edmond Halley who in 1705 was able to calculate the orbital period (about 74 – 75 years) of  this comet using historical records and the recently publish work on gravity by Sir Isaac Newton. 1P/Halley first appears in the historical record in 240 BC in a Chinese Chronicle but it is perhaps most famously depicted in the Bayeux Tapestry of 1066. The last visit was in 1986 and its next will be in 2061.

Sir Edmond Halley

Sir Edmond Halley.

Halley’s Comet in the Bayeux Tapestry

Halley’s Comet in the Bayeux Tapestry.

So, why are we remembering Halley’s Comet now? Let’s think back to the little fact I asked you to remember above – the bit about the tail of a comet remaining behind. Like all other comets, Halley’s leaves behind its tail in the form of a long stream of dust and rock fragments. Every year, the Earth passes through a number of these comet’s tails, in fact there are about twenty such occurrences. When we do pass through this debris field, a very spectacular event is seen which on a clear night provides one of the most amazing spectacles. This is a meteor shower. What happens is that the rock fragments and dust particles are drawn down through the Earth’s atmosphere by gravity. As they pass through the upper layers they start to burn up and produce hundreds and thousands of mini fireballs, lasting no more than a second or two. The shower continues until the Earth exits the tail and this can take a few hours. It you are lucky to see a meteor shower, one thing you will notice is that the meteors all appear to be generated from a single point called the radiant. We name the shower after the constellation where the radiant is located, thus the Leonid shower appears in the constellation Leo and the Perseid in Perseus.

Leonid Shower of 1833

Leonid Shower of 1833.

Leonid Shower of 2001

Leonid Shower of 2001. Photo by NASA.

Each of these showers is produced by the Earth passing through the tail of a comet. On October 21, the Earth will pass through the tail of Halley’s comet and we may be lucky to observe a shower on a clear night. This shower is called the Orionid and as the name suggests appears in the constellation of Orion. The next big shower after that will be the Leonids which will appear on the night/morning of November 16/17, though it may not be as spectacular as the 1833 shower. Keep watching the skies! Want to know more? You can find further information on Wikipedia and on the European Space Agency website or by visiting our Earth in Space gallery at the National Museum of Scotland. Plus don’t miss our Autumn Stargazing event at the National Museum of Rural Life and Astronomy Day at the National Museum of Flight.

Sankurie PyeBy Sankurie Pye, Curator, Invertebrate Biology

On Monday 7 October Fiona Ware, Rachel Edwards and I took the P6 class from East Linton Primary school to the shore at Yellowcraigs, East Lothian, as part of an international schools partnership program between East Linton Primary and Shimoni Primary School, a coastal school in Kenya.

The children were split into small groups accompanied by a teacher or adult helper and armed with a bucket. The groups went to look for plants and animals which were brought back to a central area where we discussed what had been found, before returning all the specimens to suitable a habitat. The plan had been for the children to take photographs of everything they found but they had so many questions that this will have to happen next time instead!  The children in Kenya will be doing a similar trip in the next few weeks but of course finding very different things!

Cancer pagarus

Cancer pagarus.

Asterias rubens

Asterias rubens.

Following their trip to the shore the children will create species lists/cards of the plants and animals they have seen and the two groups of children will compare and contrast their findings. Future trips will consider changes over the seasons and litter (local and washed in).  The project aims to raise awareness of marine issues on a local and global scale but will also include lots of opportunity for cultural exchange between the children.

P6 at Yellowcraigs beach

P6 at Yellowcraigs beach.

East Linton Primary has been blogging too! You can read about their day here.

By Bryony Bond, Contemporary Art Consultant

Glasgow-based artist Ilana Halperin has been researching and developing ideas for a contemporary art exhibition inspired by National Museums Scotland’s collections. The exhibition, The Library, is open from 24 May-29 September 2013. Over the past few months, she’s been looking through National Museums Scotland’s collections, finding out about minerals, fossils, molluscs and rocks and uncovering some fascinating stories. In this series of blog posts, we share some of the fantastic things she’s found.

It’s not often that you get close to something from outer space, but when meteorites hit the Earth they actually make new objects too. Artist Ilana Halperin has been looking at some of these close encounters, and finding out more about things like Tektites. Ilana explains:

 “A tektite is related to meteorite, but is formed from the Earth. When a meteorite hits the ground it melts the material around it and throws it up into the air. This melts and the reformed material is the tektite. I see a tektite as embodying the moment of contact between the meteorite and the surface of the Earth. I thought that this was beautiful, a preserved moment of contact between outer space and the Earth.”

Australite (tektite), small deformed brown metallic disc, from Uralla, Harding County, New South Wales, Australia

Australite (tektite), small deformed brown metallic disc, from Uralla, Harding County, New South Wales, Australia.

Moldavite (tektite), glassy translucent green with rough crispy surface, from Czechoslovakia

Moldavite (tektite), glassy translucent green with rough crispy .surface, from Czechoslovakia.

Indochinite (tektite), dull black elongated dumb-bell with surface pitting, from Villa Alliance, Da Lat, Lam Dong Province, Vietnam

Indochinite (tektite), dull black elongated dumb-bell with surface pitting, from Villa Alliance, Da Lat, Lam Dong Province, Vietnam.

You can visit Ilana’s website here.

Fiona WareBy Fiona Ware, Curator, Invertebrate Biology

In September 2012 Invertebrate Biologists Susan Chambers, Fiona Ware and Sankurie Pye, from the Department of Natural Sciences, ran a survey of 23 saline lagoons in the Uists, Outer Hebrides as part of a study commissioned by Scottish Natural Heritage. The aims of the study included producing a permanent collection of botanical and zoological specimens with an emphasis on specialist lagoon species. All the specimens have now been identified and we have incorporated nearly 600 jars of invertebrates into our collections at the National Museums Collections Centre and prepared over 250 botanical specimens for incorporation into the collections of the Royal Botanic Garden Edinburgh.

Collecting specimens.

Sankurie collecting specimens, Loch Fada, South Uist.

So what are saline lagoons, why are they important and what did we find out?

Saline lagoons are shallow bodies of salty water which are wholly or partially separated from the nearby sea. In some lagoons the saltiness of the water can fluctuate dramatically over time and in others there can be a distinct salinity gradient from almost marine conditions to almost freshwater conditions as distance from the influence of the sea increases. This rare and vanishing habitat is recognised under the UK’s Biodiversity Action Plan and is considered a priority habitat (‘in danger of disappearance’) under the European Habitats Directive. The threats to saline lagoons include sea level rise, pollution and human disturbance.

Collecting specimens

Fiona recording data, Loch nam Madadh, North Uist.

The Uists are known to have some of the finest lagoons in Europe but there was insufficient knowledge of the plants and animals living in them to inform a strategy for monitoring the conservation status of these internationally important sites. Our work has significantly increased this knowledge and has ensured that a voucher collection of the specialist, rare and potentially threatened invertebrates and plants that live in these lagoons are available in perpetuity. We recorded 243 species including lagoon shrimps, slaters, snails and cockles and nationally rare species including the foxtail stonewort. We also established several new records including the tube dwelling polychaete worm Ampharete acutifrons and the non-native barnacle Austrominius modestus which has gradually been spreading around the British Isles but has not previously been recorded from the Uists.

Corophium volutator

Corophium volutator.

The next step is to publish these interesting results and to continue our research into lagoon specialist species including a collaborative study with Heriot-Watt University on the molecular taxonomy of lagoon mud snails.

Thank you to Bill Crighton, Natural Sciences Volunteer, for his amazing photographs including the one shown above of Corophium volutator.

Peter DavidsonBy Peter Davidson, Curator of Minerals

OK, time to ‘fess up! I have to say I wasn’t very familiar with Ilana’s work before beginning to work with her, but once I began to delve into some of her past and current work I was immediately struck by her very personal and insightful take on geology. Viewing the work of a contemporary artist can be a confusing and mystifying business – it is sometimes difficult to discern what the artist is really trying to say. But working closely with Ilana offered curators here a unique opportunity to gain a real insight into not just how, but also why an artist chooses their subject and the way they develop their ideas and the medium chosen to portray it.

The other artists I have worked with have looked at minerals in terms of their appearance, such as colour or texture, or some inherent property like ultra-violet fluorescence, but Ilana’s exhibition was going to tell a much more personal, almost autobiographical, story.

A lot of Ilana’s work is sculptural and therefore can be ideally suited to geological themes, but a lot of her ideas and inspiration involve processes and time. We can see this in ‘The Library‘, where the pieces are framed within a context of time and the processes that went into their formation, whether billion or million year geological time-scales or the much quicker month-long creation of her intriguing pieces from mineral springs in France and Iceland.

Limestone sculpture forming in the Fontaines Pétrifiantes in the Auvergne region of France

Limestone sculpture forming in the Fontaines Pétrifiantes in the Auvergne region of France.

Limestone sculptures on display in Ilana's exhibition The Library at National Museum of Scotland

Limestone sculptures on display in Ilana’s exhibition The Library at National Museum of Scotland.

However, it is her use of mica “books” that perhaps most captures my imagination. It is surely no coincidence that they are on display here in Scotland, as it was the work of that great Scottish geologist, Charles Lyell (1797 – 1875), that taught future generations of geologists to read the story of the Earth in the rocks and minerals.

'Book' of mica etched by Ilana

‘Book’ of mica etched by Ilana.

Etched 'books' of Mica on display in The Library

Etched ‘books’ of Mica on display in The Library.

Seeing the project develop and take shape has been hugely rewarding. The frequent contact with Ilana allowed us to discuss ideas, look at specimens and give advice and help, but it was about seeing how her ideas developed from little seeds into a full blown vision that was our real reward.

Ilana Halperin: The Library was open at National Museum of Scotland until Sunday 29 September 2013.

By Bryony Bond, Contemporary Art Consultant

Glasgow-based artist Ilana Halperin researched and developed ideas for a contemporary art exhibition inspired by National Museums Scotland’s collections. The exhibition, ‘The Library’, was open from 24 May-29 September 2013. Over the months, she looked through National Museums Scotland’s collections, finding out about minerals, fossils, molluscs and rocks and uncovering some fascinating stories. In this series of blog posts, we share some of the fantastic things she found.

It’s not the usual place you’d expect to find a ghost, but National Museums Scotland actually has around twenty so-called Ghost Minerals. They’re one of the objects that artist Ilana Halperin has uncovered in the Museum’s stores and they’re more beautiful than spooky. Ilana explains:

“In a ghost mineral, one mineral has formed and then another mineral, or even the same mineral, will begin growth again and will form around it. Once it’s fully formed you can see the ‘ghost’ of one mineral inside another. They’re really very beautiful objects, with a very poetic and evocative name!”

Ghost mineral from National Museums Scotland geology collection.

Ghost mineral from National Museums Scotland geology collection

Quartz ghost mineral from National Museums Scotland geology collection

Quartz ghost mineral from National Museums Scotland geology collection.

You can visit Ilana’s website here.

By Bryony Bond, Contemporary Art Consultant

Glasgow-based artist Ilana Halperin has been researching and developing ideas for a contemporary art exhibition inspired by National Museums Scotland’s collections. The exhibition, The Library, is open from 24 May-29 September 2013. Over the past few months, she’s been looking through National Museums Scotland’s collections, finding out about minerals, fossils, molluscs and rocks and uncovering some fascinating stories. In this series of blog posts, we share some of the fantastic things she’s found.

Artist Ilana Halperin has come across some incredible discoveries during her research at National Museums Scotland, but these have got to be some of the strangest. Who knew that snails were sculptors and molluscs were the real makers of the Golden Fleece?

“While at National Museums Scotland I’ve been branching out into other areas beyond geology and mineralogy: I’ve been spending time with corals and molluscs and the curators who look after those collections. I’ve been looking at some lovely things in those departments, such as carrier shells. As these molluscs grow their shells, they also pick up bits of rocks, coral or other shells and attach them to their own. So their shells become these crazy, fabulous sculptures.

Coral specimens in the National Museums Collection Centre

Coral specimens in the National Museums Collection Centre.

Hexacorallia (coral)

Hexacorallia (coral).

Tubipora musica (organ pipe coral)

Tubipora musica (organ pipe coral).

Xenophora conchyliophora (Atlantic carrier shell)

Xenophora conchyliophora (Atlantic carrier shell).

“I’ve also been looking at golden sea threads, which are rumoured to be the substance that the Golden Fleece was composed of. The threads are made by a particular bivalve to tether itself to a substrate, like an anchor. At various points these threads have been harvested and woven together. National Museums Scotland has a really beautiful pair of gloves and a matching scarf all woven from this thread!”

Gloves and scarf made from golden sea threads

Gloves and scarf made from golden sea threads.

You can visit Ilana’s website here.

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