Sciences

DISPLAYING POSTS FILED UNDER: Sciences (241)

Sciences

Natural history - from animals to minerals, fossils to sea slugs. MV's scientists use the state's collections in important research.

MV at sea

Author
by Tim O'Hara
Publish date
4 May 2015
Comments
Comments (0)

Dr Tim O'Hara is Senior Curator of Marine Invertebrates.

It is 3am, the night is jet black, the boat heaves with the swell, and a bunch of scientists and crew dressed in full wet-weather gear are silently standing, waiting on the back deck. There is always a sense of excitement as new samples are hauled in. What bizarre deep-sea creatures will be brought up? Perhaps this time we will see the enigmatic mushroom-shaped Dendrogramma, an animal (apparently) that has confounded all efforts at classification since its first collection by Museum Victoria in 1986. Or maybe the massive sea-lice that can devour a dead whale? Or just seafloor life in incredible abundance?

Large blue and white Investigator vessel The Marine National Facility research vessel Investigator at the CSIRO wharf in Hobart.
Image: Tim O'Hara
Source: Museum Victoria

Ship's crew using machinery on deck Deploying the Smith McIntyre grab.
Image: Tim O'Hara
Source: Museum Victoria
 

On Easter Tuesday, four science staff and students from Museum Victoria (Di Bray, Mel Mackenzie and Skip Woolley and I) joined scientists around Australia on a trial voyage of Australia’s brand new research vessel, the Investigator. The idea was to test out all the gear necessary for deep-sea exploration, from iron box-like dredges, used for over 200 years to collect samples, to the high tech cameras that bounce above the seabed, worked in real time from a joystick and a bank of computer monitors in the bowels of the ship, thousands of metres above. We went south of Hobart into the Southern Ocean, specifically to look at life on underwater sea mountains in the Huon one of the Commonwealth’s recently declared marine reserves.

People in the Investigator vessel lab The sorting lab: Skip, Di and Mel facing Karen Gowlett-Holmes of CSIRO.
Image: Tim O'Hara
Source: Museum Victoria

Big camera rig on ship deck The towed deep-sea camera.
Image: Tim O'Hara
Source: Museum Victoria
 

But I had another motive to joining this trip. Next year in November I will be chief scientist of a voyage from Brisbane to Hobart that will survey Australia’s abyssal sea-plain (4000 m below sea-level). So I really wanted to learn all I could about the capabilities of the vessel and think about best practice scientific procedures to ensure we get the most out of the expedition.

The Investigator, run by the Marine National Facility funded by the Commonwealth Government, is a large (94 m), elegant and efficient platform from which to do deep-sea research. Diesel electric engines keep the noise down and high tech stabilisers prevent much of the pitch, yaw and roll that can make life miserable on smaller boats.

People on ship deck The crew deploying gear off the stern deck.
Image: Tim O'Hara
Source: Museum Victoria

Ship crew deploying gear Preparing for the next catch: MV staff in canary yellow facing Mark Lewis of from CSIRO with Mark McGrouther of the Australian Museum looking on.
Image: Tim O'Hara
Source: Museum Victoria
 

My main memories of the trip: dark thundery night skies, albatrosses, friendly company and lots of carbs to eat. All too soon we steamed back to another sunny day in Hobart. We didn’t find Dendrogramma – maybe next time.

Happy birthday field guide apps!

Author
by Nicole K
Publish date
30 April 2015
Comments
Comments (0)

One year ago today we launched eight very special apps – field guides to the fauna of every state and territory in Australia. What makes these apps so special? They were produced collaboratively by Australia's seven leading natural history museums. 

The suite of 8 Field Guide to Australian Fauna apps. The suite of 8 Field Guide to Australian Fauna apps.
Source: Museum Victoria
 

Together the seven museums produced descriptions and sourced images for over 2100 animals from terrestrial, freshwater and marine environments. The result was a suite of pocket-sized identification guides, that could be used by everyone, everywhere – and they're free.

It's been a big year for the field guide apps. They have won two international awards, a Best of the Web award and a Muse award, as well as the Northern Territory Chief Minister's award for Excellence in the Public Sector.

The apps are also highly regarded by the app stores. All 8 apps appear in iTunes' Education Collections, which feature their hand-picked recommendations for "students, teachers, parents and lifelong learners". iTunes calls these apps "indispensable tools that will inspire students in every classroom".

MV Collection Manager, Katie Smith, using the Field Guide app. MV Collection Manager, Katie Smith, using the Field Guide app.
Source: Museum Victoria
 

Over the past year, the apps have been used by the museums in school holiday activities, education programs, teacher training, community outreach and biological surveys. But we're most excited about how the public are using them – to identify animals and to learn more about Australia's amazing wildlife.

Students using Museum Victoria's app in the Forest Gallery at Melbourne Museum. Students using Museum Victoria's app in the Forest Gallery at Melbourne Museum.
Image: Mirah Lambert
Source: Museum Victoria
 

The apps have received glowing praise from their users and, since the launch, have been downloaded over 78,000 times. We're absolutely thrilled that the apps have been so well received and look forward to what the next year will bring.

The National Field Guide Apps Project was funded by an Inspiring Australia Unlocking Australia's Potential Grant. The project was a 2-year collaboration between: 

Transcribing field diaries

Author
by Nicole K
Publish date
19 March 2015
Comments
Comments (4)

Deep in Museum Victoria’s archives lie boxes of notebooks. Notebooks that contain a significant part of our museum’s history. They are the field diaries of our past curators and collection managers, produced on scientific expeditions to explore, research and discover the natural history of Australia (and beyond).

Field diaries from Museum Victoria's collection Field diaries from Museum Victoria's collection
Source: Museum Victoria
 

These field diaries are of great interest to both scientists and historians. They are filled with invaluable data, providing insights into past species’ abundance and distribution, as well as personal descriptions of the trials and wonders experienced on historic expeditions.

A photograph from Graham Brown's field diary: Mt Rufus, Tasmania (1949). A photograph from Graham Brown's field diary: Mt Rufus, Tasmania (1949).
Image: Graham Brown
Source: Museum Victoria
 

Despite the fascinating information contained within the diaries (and the interest in them), they are relatively inaccessible. They were handwritten, often in less-than-favourable conditions (picture a scientist, crouched in the bush, notebook balanced on knee).

Sketch from Allan McEvey's field journal of his expedition to Macquarie Island, 1957. Excerpt from Allan McEvey's field journal of his expedition to Macquarie Island, 1957.
Image: Allan McEvey
Source: Museum Victoria
 

We have therefore started a crowd-sourcing project to transcribe the field diaries in our collection. The pages of each diary are carefully digitised and then uploaded into DigiVol the Atlas of Living Australia’s volunteer transcription portal that was developed in collaboration with the Australian Museum. Once transcribed, the text in the diaries will be searchable. We can create lists of the species mentioned and use this information to better understand and conserve our precious biodiversity.

Our most recent transcription project is Allan McEvey's field diary of his expedition to Macquarie Island in 1957. Museum Victoria's Curator of Birds from 1955, McEvey had a passion for scientific illustration and his field diaries are filled with sketches of birds and other wildlife.

Sketches of Black-browed Albatross, <i>Diomedea melanophris</i>, from Allan McEvey's field journal of his expedition to Macquarie Island, 1957. Sketches of Black-browed Albatross, Diomedea melanophris, from Allan McEvey's field journal of his expedition to Macquarie Island, 1957.
Image: Allan McEvey
Source: Museum Victoria
 

The original diaries, along with their transcriptions, will eventually be available online via the Biodiversity Heritage Library (BHL), the world's largest online repository of biodiversity literature and archival materials.

The Australian component of BHL is managed by Museum Victoria and funded by the Atlas of Living Australia. The project has allowed us to digitise over 500 rare books, historic journals and archival field diaries. This represents over 12000 pages of Australia’s biological heritage that was previously hidden away in library archives.

Interested in becoming a transcription volunteer?

If you would like to help us unlock the observations in our historic field diaries, more information is available on the DigiVol website.

Dawn reaches Ceres

Author
by Tanya Hill
Publish date
5 March 2015
Comments
Comments (0)

When NASA’s Dawn spacecraft is captured into orbit around the dwarf planet Ceres on Friday, March 6, there will be no fanfare in mission control. In fact, the spacecraft won’t even be in radio contact. There’s no need, because Dawn’s path is set – this is a spacecraft unlike any other.

What makes Dawn unique is its ion propulsion system, which gives the spacecraft incredible manoeuvrability. Instead of using large bursts of thrust to get where it’s going, Dawn takes the slow and steady approach. Its ion engine delivers a tiny but continuous thrust that can last for days or weeks at a time.

Over the last two-and-a-half years, Dawn has been slowly reshaping its trajectory to bring it near Ceres and, most importantly, to match the dwarf planet’s speed – Ceres travels around the sun at nearly 64,000 kilometres per hour.

For other planetary missions, entering orbit is make or break. It’s an intense moment that hopefully ends in jubilant celebration when all goes as planned and the spacecraft momentously falls into orbit. But Dawn’s slow approach means that it is now right on course to guarantee capture by Ceres’ gravity.

Dawn is captured by Ceres' gravity The spacecraft’s approach trajectory with the white circles spaced at intervals of one day. This indicates the spacecraft’s speed – the closer the circles, the more slowly Dawn is moving.
Source: NASA/JPL
 

Come Friday, if the spacecraft’s propulsion were to be switched off it would remain under Ceres’ influence but would travel around the dwarf planet in a highly elliptical orbit. So over the next few weeks, Dawn will use its ion thrusters, together with Ceres’ gravity, to slowly draw it into a circular orbit – the first of four such orbital positions around the dwarf planet.

Not for the first time

Ceres is the second object that Dawn has orbited. Between July 2011 and September 2012, Dawn was in orbit around Vesta, which, like Ceres, resides in the asteroid belt located between Mars and Jupiter.

This marks the first time that one spacecraft has been able to orbit two different planetary objects. And it’s only possible because of Dawn’s ion engine.

A spacecraft powered in the usual way, using chemical propellant, would require ridiculous amounts of fuel to carry out such a mission. And even if it was possible for a spacecraft to carry that much fuel on-board, the cost of the mission would be astronomical.

Dawn's path to Ceres Dawn was launched in September 2007 and has taken the slow and steady approach to visit Vesta and now Ceres.
Source: NASA/JPL
 

At Ceres, Dawn will eventually travel in a polar orbit, travelling above the north and south poles. As it moves from north to south it will travel over the daytime side of the planet, and then during the second half of its orbit it will fly above Ceres' night side.

In its first orbital position, at a height of 13,500km, it will take 15 days for Dawn to complete one orbit. Since the planet takes only nine hours to rotate on its axis, this will allow Dawn to make a good map of the dwarf planet’s surface.

Throughout its 15-month mission, Dawn will vary its orbit three times, each one descending closer to the planet at heights of 4,400 km, 1,470 km and 375 km. To change orbits it will move through a complex series of spiral trajectories.

The descent to its lowest orbit will take two months and, during that time, Dawn will complete 160 revolutions as it constantly reorientates itself to ensure that one of its ion beams is thrusting in the right direction to continue its slow spiral descent.

Dawn's spiral descent Two months of downward spirals are needed to move Dawn into its lowest orbit - from the High Altitude Mapping Orbit (HAMO) to the Low Altitude Mapping Orbit (LAMO).
Source: NASA/JPL
 

Better than Star Wars

Ion propulsion systems, like the one that powers the Dawn spacecraft, have long been considered the next big thing for space exploration. In fact, they seemed so futuristic that they appeared in the Star Wars movies, powering Darth Vader’s TIE fighters or Twin Ion Engine fighters.

Science fiction to science fact The TIE fighters in Star Wars had twin ion engines, but Dawn does one better, with three ion engines.
Source: NASA/JPL
 

Ion engines were first used by NASA on Deep Space 1, which flew past the asteroid 9969 Braille in 1999 and comet Borrelly in 2001.

The Japanese Aerospace Exploration Agency (JAXA) has successfully used ion engines on its Hayabusa asteroid missions, the second of which was launched in December last year.

The Dawn spacecraft is fitted with three ion engines, although only one engine is used at any one time. And true to what we expect from science fiction, the spacecraft does emit a blue-green glow. This is a result of its xenon fuel.

The inner workings of an ion propulsion system. The inner workings of an ion propulsion system.
Source: NASA
 

Positively-charged xenon ions pass through two electrically charged grids. This accelerates the tiny ions and they shoot out of the engine at 144,000 kilometres per hour, providing the thrust to propel the spacecraft in the opposite direction.

Ion engines are around ten times more efficient than chemical rockets because the ions are ejected at roughly ten times the speed that a propellant is expelled by a rocket. The acceleration, however, is much slower.

It would take Dawn around four days to accelerate from 0 to 100 kilometres per hour but the trade off is that in doing so, it would only use 450grams (or just one pound) of fuel.

Why Vesta and Ceres?

Of course, the reason the technology is so marvellous is because it enables such fantastic science – the exploration of the two most massive objects in the asteroid belt, Ceres and Vesta.

The dwarf planet Ceres New images of Ceres, taken February 19 at a distance of 46,000km, show a mysterious double bright spot.
Source: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
 

Don’t let their location fool you – these are not space rocks like typical asteroids. They are big worlds and, like Earth and the other terrestrial planets, Ceres and Vesta have a layered structure.

Vesta has an iron-rich core, a silicate mantle and a crust made of basalt. While Ceres is thought to have a rocky core, an ice mantle and a dusty surface.

The ice mantle is particularly interesting. It’s thought that around 30% of Ceres’ mass may come from water and potentially some fraction of that could be liquid water. Just last year, the Herschel Space Observatory made detections of what appear to be plumes of water vapour escaping from slightly warmer regions on Ceres.

The Dawn mission will continue until June 2016 and the latest images will be regularly posted here, while the Dawn mission blog is a great way to keep up-to-date on everything that happens.

Dawn of the Solar System

The space mission was called Dawn because if we think of Ceres and Vesta as protoplanets, then by better understanding these objects, we will gain insight into the early history of our solar system.

Vesta and Ceres size comparisons Ceres and Vesta more closely reflect half-formed planets than space rocks like asteroids.
Source: NASA
 

The planets of our solar system formed by a method of accretion. Starting out as specks of dust that collided and stuck together, they then grew bigger and formed rocks until eventually they were large enough to draw in enough material to form planets.

Vesta and Ceres seemed to have halted mid-way through this process. This is most likely due to the formation of Jupiter. Its gravity may have prevented objects in the asteroid belt from coming together to finish off the planet building.

As a result, Vesta and Ceres provide a unique opportunity for understanding the early formation of the planets, because they came so close to becoming planets themselves.

The early solar system The early solar system was born out of a dusty disc encircling the sun.
Source: William Hartmann. Courtesy of UCLA
 

The ConversationThis article was originally published on The Conversation. Read the original article.

MV's new digital exhibits

Author
by Nicole K
Publish date
5 March 2015
Comments
Comments (0)

On Tuesday 3 March, Museum Victoria joined 25 Australian cultural institutions at Parliament House to launch the Australian component of the Google Cultural Institute.

Google Cultural Institute launch, 3 March 2015, Parliament House, Canberra Google Cultural Institute launch, 3 March 2015, Parliament House, Canberra
Image: Nicole Kearney
Source: Museum Victoria
 

The Google Cultural Institute is an online collection of millions of cultural treasures from over 670 museums, art galleries and archives around the world. Visitors can explore millions of artworks and artefacts in extraordinary detail, create their own galleries and share their favourite works.

Museum Victoria has been involved in the Google Art project since 2011 and was among the first institutions to partner with Google to create what is now the world's largest online museum.

Featured content on the Google Cultural Institute Featured content on the Google Cultural Institute
Source: Google
 

Tuesday's launch welcomed 14 new Australian contributors, including the Australian War Memorial, the National Portrait Gallery and the Australian Centre for the Moving Image. Over 2000 of Australia's finest cultural works are now accessible online.

Among these treasures are 226 highlights from Museum Victoria's collection. These include Aboriginal bark paintings, photographs depicting early Victorian history, and scientific illustrations that trace the development of scientific art.

In order to tell the fascinating stories behind these collection items, we have created three digital exhibitions within the Google Cultural Institute:

The Art of Science: from Rumphius to Gould (1700-1850)

The Art of Science exhibit The Art of Science exhibit
Source: Museum Victoria
 

Scientific Art in Victoria (1850-1900)

Scientific Art in Victoria exhibit Scientific Art in Victoria exhibit
Source: Museum Victoria
 

A.J. Campbell (1880-1930)

A.J. Campbell exhibit A.J. Campbell exhibit
Source: Museum Victoria
 

These exhibits include stunning photographs and illustrations, curator-narrated videos and in-depth information.

Many of these illustrations come from rare books preserved in our library and, in many cases, accompany the first published descriptions of our unique Australian fauna. The books are available online in their entirety in the Biodiversity Heritage Library, a project funded in Australia by the Atlas of Living Australia.

Predator vs predator

Author
by Patrick
Publish date
9 February 2015
Comments
Comments (0)

Museum Victoria Bioscans and other biodiversity surveys tend to focus on the bigger and more spectacular Victorian animals, such as Gippsland Water Dragons and Wedge-tailed Eagles, but some of the most interesting stories come from the little creatures. 

Spider wasp nest A partially opened nest of a spider wasp (Fabriogenia sp.). The spider prey in two of the cells have been replaced with wasp pupae.
Image: Patrick Honan
Source: Museum Victoria
 

One such highlight of the recent Gippsland Lakes Bioscan was a mud nest of a spider wasp (Fabriogenia sp.). The nest comprised six cells, each built to house a Mountain Huntsman (Isopeda montana). The cells are made from dried mud, probably mixed with eucalyptus resin to harden them. The female wasp takes about one day to construct each cell, then heads off to find a live huntsman and undertakes a life-or-death battle. Upon seeing an approaching spider wasp, a huntsman’s behaviour—excuse the anthropomorphism—is best described as a ‘mad panic’.

black wasp Adult female spider wasp, Fabriogenia sp.
Image: Patrick Honan
Source: Museum Victoria
 

The wasp is swift and deadly accurate, stinging the huntsman to immobilise it, then removing each of its legs at the first joint. She carries the spider back to her nest, lays an egg on its defenceless body, then seals it in. The egg hatches into a fat wasp grub, feeding on the internal juices of the spider until nothing but a shrivelled husk remains. The grub then forms a pupa and eventually emerges from its cell as an adult wasp, ready to continue the cycle.

Huntsman spider with no legs A dismembered huntsman removed from the mud nest. The pedipalps remain intact and the fangs are in working order.
Image: Patrick Honan
Source: Museum Victoria
 
 
Most members of this wasp family, the Pompilidae, leave the spider intact and paralyse it permanently. In this case, not only does the wasp cut off its prey’s legs, but the venom seems to immobilise the huntsman only temporarily and the spider wakes up after the cell is sealed. 

 

On a personal note, having handled spiders for more than 30 years and never being bitten, one of the spiders latched on to my finger while I was examining the nest. Like most huntsman bites there were no symptoms other than a sharp nip, and given its situation I couldn’t really blame it.

Spider wasp, spider, and spider-wasp mimicking beetle Left: Another member of the Pompilidae, the Zebra Spider Wasp (Turneromyia sp.) battles a huntsman on a gum tree in Royal Park, Melbourne. | Right: Wasp-mimicking Beetle (Trogodendron fasciculatum), also photographed in Royal Park, Melbourne.
Image: Patrick Honan
Source: Patrick Honan
 

And as a side note, spider wasps are ferocious enough to have their own mimics. The Wasp-mimicking Beetle (Trogodendron fasciculatum) looks roughly like a spider wasp, with its black and white body and orange antennae, but its behaviour is almost identical. Moving rapidly over tree trunks with twitching antennae it would, at least, be safe from roaming huntsmans.

About this blog

Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

Categories