The Adventures of Rosetta and Philae

Artist's impression of the Philae lander on the surface of the comet. Image: ESA

The European Space Agency is set to make a daring attempt to land the Philae probe on the surface of an icy comet.

The giant antenna dishes of the Canberra Deep Space Communication Complex are supporting the European Space Agency’s Rosetta spacecraft, relaying data that the refrigerator-sized Philae probe has commenced its descent to the unknown surface of Comet 67-P Churyumov-Gerasimenko.

Nearly 450 million kilometres from Earth and travelling at 18 kilometres per second, the bizarre ice, dust and rock strewn surface of the 5 kilometre long, 10 billion tonne comet called Churyumov-Gerasimenko will be stage for one of the most daring landing attempts in the history of space exploration.

The Rosetta spacecraft drops off the Philae lander for a 7 hour descent towards the comet's surface. Image: ESA

After a 10-year journey, the European Space Agency’s (ESA) Rosetta spacecraft arrived at the comet (also known as Comet 67P) in August 2014. For the past several months Rosetta scientists have been using the spacecraft’s instruments to analyse and photograph the comet’s surface looking for a potential landing site. Several candidate locations were chosen but one, ‘Site J’, seemed to present the best chance for a successful touchdown of Rosetta’s ‘Philae’ probe on the comet’s unexplored surface.

Comet 67P Churyumov Gerasimenko is a relative newcomer to the inner solar system, possibly originating from the Oort Cloud. Image: ESA

Site J, now called Agilkia (after an island in the Nile River), however, only offers the instrument-laden Philae lander a 75% chance of a safe touchdown at 3.02am (AEDST) on Thursday 13th November. Low gravity, car-sized boulders, 30 metre cliffs, deep holes and an unknown surface composition are just some hazards that the unaided robotic probe will have to face.

Keeping an eye on events as they unfold will be the giant antenna dishes of NASA’s Deep Space Network and those of the European Space Agency, which have tracked the spacecraft throughout its 10 year adventure.

Deep Space Station 34 in Canberra is supporting the European Space Agency's daring comet mission. Image: NASA/JPL

At the CSIRO-managed Canberra Deep Space Communication Complex (CDSCC), Deep Space Station 34 (DSS34) will listen in on relayed signals from the Rosetta mothercraft as it releases the Philae probe on a 7-hour descent towards the comet’s surface. Along withESA’s New Norcia antenna near Perth, separation of the two craft will be confirmed late Wednesday evening (12th November). DSS34 will provide ongoing back-up communication coverage between the Rosetta/Philae spacecraft and the anxious science team located at ESA’s mission control centre in Darmstadt, Germany.

The path Philae will take to the comet's surface. Image: ESA

As the Earth continues to turn and the spacecraft fall out of Australia’s view, the Canberra and New Norcia antennas will hand over to sister stations in Spain and Argentina for the last leg of the journey and the historic touchdown signal on Thursday morning (13th November).

Follow the adventures of Rosetta and Philae. Image: ESA

The European Space Agency has been doing a remarkable job engaging the public in this great adventure. You can following along with the events of Rosetta and Philae’s great adventure on their mission blog. ESA is also broadcasting live coverage of the descent and landing. Updates also via Twitter – Rosetta | Philae

This originally appeared on the CSIRO Universe blog.


Make our ASKAP telescope a star of the night sky

By Emily Lehmann

There’s a new star in the making in the world of astronomy, with our Australian Square Kilometre Array Pathfinder (ASKAP) named as a finalist in The Australian Innovation Challenge’s Manufacturing, Construction and Infrastructure category*.

We recently shared some of the first images produced  by the amazing ASKAP telescope. It comprises a cluster of 36 radio dishes that work in conjunction with a powerful supercomputer to form what is, in effect, a single composite radio telescope a massive six kilometres across.

This allows it to survey the night sky very quickly, taking panoramic snapshots over 100 times the size of the full moon (as viewed from Earth, of course!).

One of the ASKAP radio dishes, located in a remote area of Western Australia.

One of the ASKAP radio dishes, located in a remote area of Western Australia.

The world-leading facility is revolutionising astronomy, and this award nomination is a welcome recognition. You can vote for it here – just scroll down to the bottom of the page.

Now, for all you space cadets, here’s five astronomical facts about why ASKAP is out of this world and a sure-fire winner:

  1. ASKAP’s 36 radio dishes, each 12 metres in diameter, give it the capacity to scan the whole sky and make it sensitive to whisper-quiet signals from the Milky Way.
  2. ASKAP is an outstanding telescope in its own right, as well as a technology demonstrator for the Square Kilometre Array (SKA). This pioneering technology will make ASKAP the fastest radio telescope in the world for surveying the sky.
  3. Once built, the SKA will comprise of a vast army of radio receivers distributed over tens to hundreds of kilometres in remote areas of Western Australia and Africa.
  4. The SKA will generate five million million bytes of information in its first day. That’s almost as many grains of sand on all of the world’s beaches.
  5. ASKAP is located in the remote Murchison Shire of Western Australia, which was chosen because there is hardly any human activity and so little background radio noise.

ASKAP is one of four CSIRO projects already in the running for different categories in the Oz’s Innovation Challenge (we’ve also written about swarm sensing and Direct Nickel). You can #voteCSIRO for any and all of them – just follow the links from the Challenge’s home page!


Under a blood red moon … or not

We asked, and you surely delivered. We put out a call for your photos of the lunar eclipse, and got so many that for a moment we were afraid we might break Facebook. Here are some of our favourites.

It was a little cloudy in Melbourne, but Rhonda Baum still managed to sneak a shot through the gloom.

Eclipse through clouds

Image by Rhonda Baum

Clear skies in Port Lincoln helped Peter Knife get this.

Lunar eclipse Port Lincoln

Image by Peter Knife

Meanwhile, in Albury, the eclipse really turned it on for Petra de Ruyter.

Eclipse from Albury

Image by Petra de Ruyter

And Tamworth lived up to its claim to be Big Sky Country.

Lunar eclipse from Tamworth

Image by Ekiama Apalisok-Brice

Some managed to catch the purple tones.

Purple moon

Image by Lisa Belgrave

Lunar eclipse purple

Image by Samantha Bright

Others managed to catch tones we found a little surprising. There’s always one, isn’t there, Peter Feeney?

Green moon

Image by Peter Feeney

We got images from Japan.

Lunar eclipse Japan

Image by Ivy B Ueama

And Indonesia.

Lunar eclipse Indonesia

Image by Muhammad Hasbi Alfarizi

We got spectacular montages.

Lunar eclipse montage

Image by Kelly Wilson

But for some of us, the weather didn’t co-operate at all. Kim Cook was able to remind those of us who missed out that clouds can be beautiful too.

Sunset clouds

Image by Kim Cook

But if we’re honest, we have to admit that Ali Ceyhan spoke for all of us who didn’t get to see it.

Lunar eclipse meme

Image by Ali Ceyhan

Next time, next time … And our sincere thanks to all of you for your photos.


Australia’s astronomy future in a climate of cutbacks

Parkes radio telescope

What future for the Parkes radio telescope amid the CSIRO cutbacks? Image: Wayne England

By Lewis Ball, CSIRO

The future looks very bright for Australian radio astronomy but it was somewhat clouded earlier this year when CSIRO’s radio astronomy program took a dramatic hit in the Australian federal budget.

CSIRO has cut its funding for radio astronomy by 15%, down A$3.5 million to A$17 million for the 2014-15 financial year. The result will be a reduction of about 30 staff from the plan of just three months ago.

The cuts will impact most heavily on CSIRO’s in-house astronomy research, on the operation of the Parkes radio telescope – instantly recognisable from the movie The Dish – on the less well known but tremendously productive Australia Telescope Compact Array near Narrabri and on the Mopra Telescope near Coonabarabran, all in New South Wales.

The Australia Telescope Compact Array.

The Australia Telescope Compact Array. Image: D. Smyth

About two-thirds of ATNF’s staffing reduction will be effected through not filling planned new roles, most prominent of which was to be a CSIRO “SKA Chief Scientist”. A third of the reduction will be through involuntary redundancies. Eight staff across sites in Sydney, Parkes, Narrabri and Geraldton have already been informed that their roles are expected to cease.

The speed of implementation of such a substantial funding reduction forces swift action. This has unsettled staff and the broader astronomy community, but it hasn’t changed the broad direction of CSIRO’s astronomy program.

World leaders in radio astronomy

Australian scientists and engineers are world leaders in radio astronomy, both in understanding our universe and in developing some of the most innovative technologies used to gain that understanding, and have been for 50 years.

CSIRO’s Australia Telescope National Facility (ATNF) has been integral to the discovery of the first double pulsar system (a long-sought holy grail of astronomy), the identification of a previously unknown arm of our own galaxy, the Milky Way, and the invention of Wi-Fi now so embedded in everyday communications.

For the past decade CSIRO has been steadily changing the way it operates its radio astronomy facilities. CSIRO’s highest priority is the pursuit of science enabled by the development of an innovative new technology that provides an unprecedented wide field of view.

This uses “Phased Array Feeds” (PAFs) as multi-pixel radio cameras at the focus of dishes. PAFs are being deployed in the Australian SKA Pathfinder (ASKAP), in Western Australia, which will be the fastest radio telescope in the world for surveying the sky.

ASKAP telescopes in WA

High-speed radio astronomy surveys will be possible thanks to the PAF receivers (green chequerboard at top of the quadrupod) on the ASKAP telescopes in Western Australia.

ASKAP is in the early stages of commissioning. It is just now starting to demonstrate the new capabilities obtainable with a PAF-equipped array.

ASKAP is an outstanding telescope in its own right but is also a pathfinder to the huge Square Kilometre Array (SKA). This enormous project will build the world’s biggest astronomy observatory in Australia and southern Africa. It’s also the most expensive at a cost of around A$2.5 billion.

Cutbacks at The Dish

To resource these exciting developments, CSIRO has been reducing costs and staffing at its existing facilities, including the venerable Parkes Dish. This is a painful but necessary process. The most recent funding cuts will result in more pain.

Astronomers will no longer have the option of travelling to the Compact Array to operate the telescope to collect their data. They can run the telescope from CSIRO’s operations centre in Sydney, or from their own university, or from anywhere in the world via an internet connection.

Astronomers who use the Parkes telescope have been doing this for the past year after a very successful program to make the 50-year-old dish remotely operable. That is pretty amazing for a machine built before the advent of modern computers.

Parkes telescope

The Parkes dish gets the remote treatment.
Image: John Sarkissian

For many decades Parkes staff have swapped detector systems or “radio receivers” in and out of the focus cabin, the box at the tip of the tripod that sits about 64 metres off the ground. Each receiver operates at different wavelengths and offers quite different types of science.

It seems likely that CSIRO will offer just two Parkes receivers for at least the next six to 12 months, since it will no longer have the staff needed to swap receivers. Similar reductions in the capability of the Compact Array will also be needed to fit within the budget.

The future

While the current changes are painful, the future is incredibly exciting. The direction of Australia’s astronomy is described in the Decadal Plan for Australian Astronomy for 2006–2015. It identifies participation in the SKA and access to the world’s largest optical telescopes as the two highest priorities for Australian astronomy.

We are making progress on both fronts, despite some significant challenges. The process to develop the plan for the next decade is well in hand under the stewardship of the National Committee for Astronomy.

Phased arrays are also at the heart of the Murchison Widefield Array (MWA), another innovative SKA precursor that has been in operation for a little over a year.

ASKAP and the MWA are located in the Murchison region of Western Australia, chosen because it has a tremendously low level of human activity and so astonishingly little background radio noise.

This radio quietness is the equivalent of the dark skies so important for optical astronomers. Less noise means astronomers are better able to detect and study the incredibly weak radio signals from the most distant parts of the universe.

This freedom from radio interference is a unique resource available only in remote parts of Australia and is essential for ASKAP, MWA and much of the science targeted by the SKA.

PAFs

Prototype of the more sensitive second-generation PAFs to be deployed on ASKAP undergoing tests in Western Australia in August 2014.
Image: A. Hotan

The wide fields of view of ASKAP and the MWA enable unprecedented studies of the entire radio sky. Astronomers will measure the radio emission of millions of galaxies and complete massive surveys that for the first time will connect radio astronomy to the more mature field of optical astronomy.

Mapping the sky with EMU and WALLABY

The two highest priority projects for ASKAP are called the Evolutionary Map of the Universe (EMU) and the Widefield ASKAP L-Band Legacy All-Sky Blind Survey (WALLABY).

Both will survey millions of galaxies and together they will trace the formation and evolution of stars, galaxies and massive black holes to help us explore the large-scale structure of the universe.

The MWA is already producing great science targeted at the detection of intergalactic hydrogen gas during what’s known as the “epoch of reionisation” when the first stars in the universe began to shine.

With the SKA we aim to understand what the mysterious dark matter and dark energy are. We may also provide another spin-off such as the Wi-Fi technology, which came from CSIRO efforts to detect the evaporating black holes predicted by Stephen Hawking.

Advances in data-mining or processing techniques driven by the astonishing data rates that will be collected by the thousands of SKA antennas deployed across the Australian and African continents might provide the most fertile ground of all, illustrating once again the long-term benefits of investing in cutting-edge science.

Lewis Ball has received funding from the Australian Research Council. CSIRO Astronomy and Space Science receives funding from a variety of government sources, and from NASA/JPL.

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


Why the stuff between the stars is like a glass of beer

By Nola Wilkinson  

Ever wondered what there is between the stars? Dr Naomi McClure-Griffiths not only wonders about it, she’s on a mission to find out.

Naomi is fascinated with the life of stars, the behaviour of interstellar gas, and how gas and stars interact.  “As an astronomer, I’d like to understand how the galaxy formed and how it’s living its life,” she says.

Naomi has conducted a massive survey of all the hydrogen gas in and around in the Milky Way. In doing so, she has shown that the stuff between the stars is actually foamy.

“The galaxy is much more frothy and bubbly than we ever thought. It looks like the head on a glass of beer.”

Very large stars, 8-20 times the size of our sun, experience dramatic supernova explosions that push gas out of the galaxy via solar winds travelling at up to 1000 kilometres a second.

It is these solar winds that blow bubbles in the gas between the stars, creating a frothy, foamy appearance.

Watch this video to find out more about Naomi and her amazing work:

Naomi’s team undertook the Galactic All Sky Survey using our Parkes telescope and is planning future work using our ASKAP radio telescope.


The first images from ASKAP reveal slices through space

Three of the dishes used by the Australian Square Kilometre Array Pathfinder telescope.

Three of the dishes used by the Australian Square Kilometre Array Pathfinder telescope. Image: CSIRO / Terrace Photographers

By Lisa Harvey-Smith, CSIRO

The first images from Australia’s Square Kilometre Array Pathfinder (ASKAP) telescope have given scientists a sneak peek at the potential images to come from the much larger Square Kilometre Array (SKA) telescope currently being developed.

ASKAP comprises a cluster of 36 large radio dishes that work together with a powerful supercomputer to form (in effect) a single composite radio telescope 6km across.

What makes ASKAP truly special is the wide-angle “radio cameras”, known as phased array feeds, which can take up to 36 images of the sky simultaneously and stitch them together to generate a panoramic image.

Why panoramic vision?

Traditional radio telescope arrays such as the Australia Telescope Compact Array near Narrabri, NSW, are powerful probes of deep-space objects. But their limited field of view (approximately equivalent to the full moon) means that undertaking major research projects such as studying the structure of the Milky Way, or carrying out a census of millions of galaxies, is slow, painstaking work that can take many years to realise.

The special wide-angle radio receivers on ASKAP will increase the telescope’s field of vision 30 times, allowing astronomers to build up an encyclopedic knowledge of the sky.

This technological leap will enable us to study many astrophysical phenomena that are currently out of reach, including the evolution of galaxies and cosmic magnetism over billions of years.

For the past 12 months a team of CSIRO astronomers has been testing these novel radio cameras fitted on a test array of six antennas.

The first task for the team was to test the ability of the cameras to image wide fields-of-view and thus demonstrate ASKAP’s main competitive advantage. The results were impressive!

A wide-field image of the sky taken with the ASKAP test array.

A wide-field image of the sky taken with the ASKAP test array. Image: I. Heywood/ACES team, CSIRO

One of the first test images from the ASKAP test array is seen above. The hundreds of star-like points are actually galaxies, each containing billions of stars, seen in radio waves. Using CSIRO’s new radio cameras, nine overlapping images were taken simultaneously and stitched together.

The resulting image covers an area of sky more than five times greater than is normally visible with a radio telescope. The information contained in such images will help us to rapidly build up a picture of the evolution of galaxies over several billion years.

Where next for ASKAP to look

On the back of this success, the commissioning team turned the telescope to the Sculptor or “silver coin” galaxy to test its ability to study deep-space objects.

Sculptor is a spiral galaxy like our own Milky Way, but appears elongated as it is seen almost edge-on from earth.

The Sculptor galaxy seen rotating edge-on using the ASKAP test array.

The Sculptor galaxy seen rotating edge-on using the ASKAP test array. Image: P. Serra/ACES Team, CSIRO

This image (above) shows the radio waves emitted by hydrogen gas that is swirling in an almost circular motion around the galaxy as it rotates.

The red side of the galaxy is moving away from us and the blue side is moving towards us. The speed of rotation tells us the galaxy’s mass.

The team has also tested the ability of the telescope to “weigh” the gas in very distant galaxies. The image (below) shows a grouping of overlapping galaxies called a gravitational lens.

Gravitational lens image

A cluster of galaxies aligned to form a ‘gravitational lens’ was captured using ASKAP’s test array.

Seven billion years ago, radio waves from a distant galaxy were absorbed by a foreground galaxy in this group. That signal was processed by ASKAP to form the spectrum (top right in the above image).

Although not visually pretty, this type of observation has enormous scientific value, allowing astronomers to understand how quickly galaxies use up their star-forming fuel.

The latest demonstration with the ASKAP test array is a movie (below) of layers through a cloud of gas in our Milky Way.

This series of images – similar to an MRI scan imaging slices through the human body – demonstrates the ability of the telescope to measure the intricate motions of the spiral arms of the Milky Way and other galaxies.

Building to the bigger array

These images are just the beginning of a new era in radio astronomy, starting with SKA pathfinders like ASKAP and culminating in the construction of the SKA radio telescope.

Once built, the SKA will comprise a vast army of radio receivers distributed over tens to hundreds of kilometres in remote areas of Western Australia and South Africa.

Just like ASKAP combines signals from several dishes, the SKA will use a supercomputer to build up a composite image of the sky.

Each ensemble of antennas will work together to photograph distant astronomical objects that are so faint, that they can’t be seen at all with current technology.

The SKA will thereby open up vast tracts of unexplored space to scientific study, making it a game-changer in astrophysical and cosmological research.

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


Aboriginal people – how to misunderstand their science

Painted Aboriginal face

We still have so much to learn about Aboriginal history and culture. Image: Shutterstock / John Austin

By Ray Norris, Chief Research Scientist, Astronomy & Space Science

Just one generation ago Australian schoolkids were taught that Aboriginal people couldn’t count beyond five, wandered the desert scavenging for food, had no civilisation, couldn’t navigate and peacefully acquiesced when Western Civilisation rescued them in 1788.

How did we get it so wrong?

Australian historian Bill Gammage and others have shown that for many years land was carefully managed by Aboriginal people to maximise productivity. This resulted in fantastically fertile soils, now exploited and almost destroyed by intensive agriculture.

In some cases, Aboriginal people had sophisticated number systems, knew bush medicine, and navigated using stars and oral maps to support flourishing trade routes across the country.

They mounted fierce resistance to the British invaders, and sometimes won significant military victories such as the raids by Aboriginal warrior Pemulwuy.

Engraving of Galileo

Australian aborigines knew more about tides than Galileo Galilei (engraving from about 1662). Image: Shutterstock / Iryna1

Only now are we starting to understand Aboriginal intellectual and scientific achievements.

The Yolngu people, in north eastern Arnhem Land in the Northern Territory, long recognised how the tides are linked to the phases of the moon.

Back in the early 17th century, Italian scientist Galileo Galilei was still proclaiming, incorrectly, that the moon had nothing to do with tides.

Some Aboriginal people had figured out how eclipses work, and knew how the planets moved differently from the stars. They used this knowledge to regulate the cycles of travel from one place to another, maximising the availability of seasonal foods.

Why are we only finding this out now?

We owe much of our knowledge about pre-European contact Aboriginal culture to the great anthropologists of the 20th century. Their massive tomes tell us much about Aboriginal art, songs and spirituality, but are strangely silent about intellectual achievements.

They say very little about Aboriginal understanding of how the world works, or how they navigated. In anthropologist Adolphus Elkin’s 1938 book The Australian Aborigines: How to Understand Them he appears to have heard at least one songline (an oral map) without noting its significance.

[…] its cycle of the hero’s experiences as he journeyed from the north coast south and then back again north […] now in that country, then in another place, and so on, ever coming nearer until at last it was just where we were making the recording.

How could these giants of anthropology not recognise the significance of what they had been told?

The answer dawned on me when I gave a talk on Aboriginal navigation at the National Library of Australia, and posed this same question to the audience.

Afterwards, one of Elkin’s PhD students told me that Elkin worked within fixed ideas about what constituted Aboriginal culture. I realised she was describing what the American philosopher Thomas Kuhn referred to when he coined the term “paradigm”.

The paradigm problem

According to Kuhn, all of us (even scientists and anthropologists) are fallible. We grow up with a paradigm (such as “Aboriginal culture is primitive”) which we accept as true. Anything that doesn’t fit into that paradigm is dismissed as irrelevant or aberrant.

Only 200 years ago, people discussed whether Aboriginal people were “sub-human”. Ideas change slowly, and the underlying message lingers on, long after it has been falsified.

As late as 1923 Aboriginal Australians were described as “a very primitive race of people”.

Not so primitive

Cave painting

Aboriginal culture is more than just cave painting and artwork. Image: Kitch Bain

The prevailing paradigm in Elkin’s time was that Aboriginal culture was primitive, and Aboriginal people couldn’t possibly say anything useful about how to manage the land, or how to navigate.

So an anthropologist might study the Aboriginal people as objects, just as a biologist might study insects under a microscope, but would learn nothing from Aboriginal people themselves.

Even now, the paradigm lives on. In my experience, well-educated white Australians, trying so hard to be politically correct, often still seem to find it difficult to escape their childhood image of “primitive” Aboriginal people.

We must overcome the intellectual inertia that keeps us in that old paradigm, stopping us from recognising the enormous contribution that Aboriginal culture can make to our understanding of the world, and to our attempts to manage it.

As Thomas Kuhn said:

[…] when paradigms change, the world itself changes with them.

Still to learn

In recent years, it has become clear that traditional Aboriginal people knew a great deal about the sky, knew the cycles of movements of the stars and the complex motions of the sun, moon and planets.

There is even found a sort of “Aboriginal Stonehenge”, that points to the sunset on midsummers day and midwinters day. And I suspect that this is only the tip of the iceberg of Aboriginal astronomy.

So in the debate about whether our schools should include Aboriginal perspectives in their lessons, I argue that kids studying science today could also learn much from the way that pre-contact Aboriginal people used observation to build a picture of the world around them.

This “ethno-science” is similar to modern science in many ways, but is couched in appropriate cultural terms, without expensive telescopes and particle accelerators.

So if you want to learn about the essence of how science works, how people learn to solve practical problems, the answer may be clearer in an Aboriginal community than in a high-tech laboratory.

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


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