Telescope View of Sky from Big Hill, NSW. [Ryan Wick, Flickr]

Keeping an eye on citizen astronomy

Amateur astronomers in Russia made a discovery last week any professional would envy – it seems they may have identified the remnants of the ill-fated Soviet Mars 3 lander, 30 years after it lost contact with Earth.

Photos taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO) in 2007 show what appears to be the parachute, heat shield, and retrorocket of the Mars 3 lander.

But finding object as small as an 11-metre-wide parachute on the surface of Mars takes a lot of work, especially as the most promising photo – a section of which is below – contains 1.2 billion pixels and requires 2,500 computer screens to view the entire image at full resolution.

The possible Mars 3 lander hardware was found by a group of Russian citizen enthusiasts.
[NASA/JPL-Caltech/University of Arizona]

This is the most recent example of how citizen science is blossoming – and getting results – within the field of astronomy. There is a wealth of amateurs who pursue backyard observations as a hobby and their efforts make headlines worldwide. Some have historically contributed to science by finding comets, tracking asteroids, the Search for Extraterrestrial Intelligence (SETI) program, and monitoring stars.

The Soviet Mars 3 lander before venturing
to Mars in 1971. [Armael, Wikimedia Commons]

One of the most visible citizen-science projects in astronomy and astrophysics is the “Zooniverse” which invites members of the public to analyse data ranging from determining the shape of galaxies to trying to detect if any planets outside our solar system orbit stars.

The Galaxy Zoo

The Zooniverse project grew out of the Galaxy Zoo project which was set up to determine the shape, or morphology, of galaxies.

Galaxy shape is a useful visual indicator to professional astronomers about the state of the galaxy and the physical processes which may be going on inside it.

While there are many types of galaxy shapes, bright galaxies usually fall into one of three categories:
     • spiral
     • elliptical
     • irregular

The Sloan Digital Sky Survey, an internationally funded project to map the sky, photographed and mapped more than 930,000 galaxies over eight years.

Faced with an overwhelming amount of data to sift through, astronomers conceived of the Galaxy Zoo idea to ask the general public for help to look through all the data and classify the shapes of galaxies.

Three main galaxy shapes (from left): spiral galaxy PIA09337, elliptical galaxy NGC 1316, and irregular galaxy NGC 3738.
[NASA]

Since this requires little background knowledge, any member of the public can help so long as they have an internet connection.

Using a simple, clickable interface, users can say whether galaxies are rounded, have spiral arms, have any unusual or distinguishing features, or whether they want to discuss the objects in more detail.

This is especially important in a data-rich field like astronomy: users can sometimes be the first human being to actually look at a galaxy since most of the processing of the images they examine have been done by computers.

Getting the numbers up

For all the excellent work done by the general public, there will still be disagreement about the exact classification of galaxy shapes – and this, fundamentally, raises questions about data integrity.

[Gwydion M. Williams]

This is why the Galaxy Zoo project aims to have at least 20 people attempt to classify each galaxy.

To use the data in professional research, astronomers have to look for disagreements between members of the general public.

Taking a threshold level is one way to solve the problem. If, say, 80% of respondents say a galaxy is a particular shape, that is a reasonable way forward and is perfectly suitable for some analysis purposes.

The cost of this may be that there is a high number of “unclassified” galaxies where there is large disagreement, perhaps caused by very few individuals having looked at a galaxy.

And the results are …

There have been a healthy number of scientific publications arising from the Galaxy Zoo project team, including the relationship between galaxy colour and environment and studies of highly unusual objects such as “Hanny’s Voorwerp” – a possible light echo from quasars (the brightest objects in the known universe).

[NASA]

In my own research, we recently used data from Galaxy Zoo to explore the connection between galaxy morphology, galaxy mass, and the likelihood of hosting an Active Galactic Nucleus (AGN) in a massive cluster of galaxies – a collection of gravitationally bound galaxies and one of the most extreme “environments” in which a galaxy can live.

We used the data to explain an earlier result that red and passive spiral galaxies are, in the majority, also massive and similar in nature to most of the massive elliptically shaped cluster galaxies.

We then inferred that the life cycle of high and low mass cluster galaxies are markedly different.

But we wouldn’t have been able to make these conclusions without the citizen scientists who classified the bulk of the data for us – something for which we are extremely appreciative.

And who knows? As shown by the Russian amateur astronomers sifting through NASA’s high-resolution photos, the next big astronomy discovery could be made by you.

About the Author

Kevin Pimbblet, from Monash University, is an experienced observational astronomer whose core research interests cover a number of modern topics in extra-galactic astrophysics, large-scale structure of the Universe and cosmology.

Kevin Pimbblet receives funding from the Australian Research Council.

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

Space archaeology is a recent research method scientists

FlyingSinger, Flickr.com, CC BY 2.0

have begun using in order to evaluate man-made items found across the galaxy. These artifacts can range from orbital debris, satellites, and other various objects humans have placed on the Moon and Mars. Through these artifacts we keep track of and discover in space we monitor and interpret the adventures of man as we travel into the world beyond. 

The cultural resource or heritage management is in charge of evaluating the significance of space sites and artifacts according to national and inter-national preservation laws. They examine how and why these outer space artifacts and sites of our recent history should be preserved for our future generations to view. For example, they decide on whether or not the site where Neil Armstrong landed on the Moon should be preserved so that we can see the first steps man made on the moon. 

NASA Goddard Photo and Video, Flickr.com, CC BY 2.0

People like Beth O’Leary, an associate professor of Anthropology at New Mexico State University (NMSU) and co-editor of the handbook of space engineering, archaeology, and heritage, have dedicated themselves to preserve the many artifacts on the moon. One site she had dedicated herself in watching over is the flag and the footprint of Neil Armstrong left to prove he walked on the Moon. With a grant from NASA, O’Leary helped establish the Lunar Legacy Project; which aims to preserve the historical information found at Tranquility Base. She previously stated, “We need to prepare for the future because in fifty years many travelers may go to the moon, if the site is not protected, what will be left?”

Idaho National Library, Flickr.com, CC BY 2.0

There are artifacts left behind in space other than those found on the Moon and Mars, but some of them threaten the safety of Earth. Since some of these artifacts, like low orbiting satellites and stations, currently run the risk of impacting each other and other space objects; instead of them being labeled as our cultural heritage they are considered space junk. An informed decision on the risk of letting them continue to orbit or destroying them should be made while keeping their international and historical significance in mind.

Because of the global safety dilemma there is the potential of parts of space archaeological record being destroyed and possibly forgotten. The question of which artifacts are culturally important and which are not is being asked, but how exactly are we suppose to answer. As humans living in the world today we have no idea what artifacts will have relevance and which will not in the future. Making us run the risk of leaving a missing link in our record of space exploration. For example, Wall-E from the Disney movie, feeds his curiosity by examining items he comes across in the mountains of trash left by the humans. He finds a woman’s bra and begins examining it and placing it on his head as a hat and over his eyes as a blindfold, confused about what the primary purpose of his finding was. Will we be just as confused when looking at the space artifacts we left behind in the future?

For More Information

• http://www.academia.edu/167541/The_archaeology_of_orbital_space
• http://alumnae.mtholyoke.edu/blog/beth-oleary-74-space-archaeologist-lauds-lunar-legacy/
• http://www.archaeologyexpert.co.uk/archaeologyfromouterspace.html
• https://theconversation.edu.au/saving-space-junk-our-cultural-heritage-in-orbit-6025
• http://archive.archaeology.org/0411/etc/space.html
• https://wp.carleton.edu/historicalarchaeology/2012/11/11/wall-e-and-archaeology-match-made-in-heaven-or-just-outer-space/
• http://articles.latimes.com/2009/jun/01/opinion/oe-walsh1
• http://www.nasa.gov/centers/goddard/news/releases/2013/13-013.html

The Spiro Mounds of Oklahoma are only a few miles away from the city Spiro. The mound site consists of 12 mounds, an elite village, and a support village within 150 acres of land. Originally in prehistoric times the mounds area was home mostly to nomads, but as cultures and society began to emerge when ancient people began to become sedentary the Spiro Mounds also transformed into what they are today. By 800 BCE the Spiro Mounds became a permanent settlement that was used until 1450 BCE.

Heironymous Rowe, commons.wikimedia.org,  CC BY-SA 3.0

Heironymous Rowe, commons.wikimedia.org, CC BY-SA 3.0

During that time period, which is typically called the Mississippian period the Spiro culture flourished. Archaeological evidence shows that Spiro culture had economic, political, and religious all the way from the Great Lakes to the east coast and the Gulf of Mexico to the Gulf of California. They had an extensive religious center developed as well as a highly developed trade network. The Spiro political system was also able to exert total control over the entire South East. In its height the Spiro people shared an iconographic writing system with over 60 other tribes along with horticulture and extensive ceremonies.

No one is certain as to why the Spiro Mounds were abandoned or why the culture declined, but it was probably caused by a number of environmental, cultural, and political factors. Today the Spiro Mounds are available for the public to explore and at the Spiro Mounds Archaeological Center many artifacts including artistic and utilitarian prehistoric Native American artifacts.

To Find Out More Check Out: http://www.okhistory.org/sites/spiromounds

J. Stephan Con, Flickr.com, CC BY- NC 2.0

The Cherokee Heritage Center is located in Park Hill, Oklahoma with an Ancient Village and the Trail of Tears being its two major exhibits. It hosts a wide variety of events such as: beading and pottery workshops, educational lectures, and art shows. They also focus on educating the public on Cherokee culture, language, and history. They offer courses in Cherokee Humanities which are accredited courses through Northeastern State University, and other cultural classes including pottery, basket weaving, bead work and making Cherokee moccasins and feather caps. During the Indian Territorial Days they offer the public a way to experience life of what is was like to live in a Cherokee village 300 years ago through activities, games, and living history.

Unknown, commons.wikimedia.org, CC BY-SA 3.0

The Ancient Village attraction was opened in 1967 and the location was chosen because it used to be home to the Cherokee Female Seminary. After years of research on Cherokee culture and history construction began. The stations visitors have the option to interact with are stickball, basket making, flintknapping, blowguns, and dugout canoes.

The Trail of Tears exhibit works with the National Park Services in order to permanently house the exhibit which displays the forced removal of Indians from their land onto reservations. It shows the six stages the Indians went through: pre-removal, court battles, prisoners with no crime, a look at the trails other tribes took, removal, and starting over. Each stage is supported by documentation and artifacts in order to display Cherokee culture and history.

Wolfgang Sauber, commons.wikimedia.org, CC BY-SA 3.0

One of the major events which will occur at the Cherokee Heritage Center from April 20th to May 27th is the Trail of Tears 42nd Annual Art Show and Sale. The Art Show displays authentic Native American art made by 93 Native American artists from 15 Tribal Nations. The art show will feature 162 art pieces including paintings, sculpture, basketry, jewelry, miniatures, and pottery.

To Learn More Check Out:
http://www.cherokeeheritage.org/

Hunting or climate change? Megafauna extinction debate narrows

By Christopher Johnson, University of Tasmania

What is the oldest debate in Australian science? Probably, the argument over what caused extinction of our Pleistocene megafauna – the diprotodons, giant kangaroos, marsupial tapirs, über-echidnas and other big and bizarre creatures that used to live here.

Giant Haast's Eagle attacking New Zealand Moa
[John Megahan, PLoS Biology, CC BY- 2.5]

In 1877 the great English anatomist Sir Richard Owen suggested that these big animals had been driven extinct by “the hostile agency of man”. That is, hunting did it, in a process we now call overkill. Other people responded that climate change must have been the cause, and it was on.

A string of recent studies from a wide range of disciplines – geochronology, palaeoecology, palaeontology, and ecological modelling – have supported Owen’s opinion. But the argument continues. Why?

The main reason is that many Australian archaeologists reject overkill. They have looked for direct evidence that people killed megafauna, and they haven’t found it. No great piles of bones around ancient campsites; no diprotodon skeletons with spears stuck in their ribs; no arsenal of specialised weapons for bringing down large prey. Very few archaeological sites even have remains of people and megafauna in close association.

Some archaeologists conclude that megafauna-hunting just did not happen, or if it happened it was rare and insignificant. Often this conclusion is stated with a ringing confidence that dismisses all non-archaeological evidence for overkill.

But they have not asked a crucial question: if people did hunt megafauna to extinction, how much evidence of killing should we now be able to get from archaeological sites? A new paper by archaeologists Todd Surovell and Brigid Grund suggests the answer to that question is “very little or none”.

Surovell and Grund point out, first, that the period when archaeological evidence of killing of megafauna could have been formed is a small fraction of the total archaeological record of Australia. People arrived here between about 50,000 and 40,000 years ago. This is also the interval during which animals like diprotodon disappeared. A comparison of archaeological and fossil dates suggests humans and megafauna overlapped for only about 4,000 years continent-wide, and modelling suggests that if hunting caused extinction it would have been all over in less than 1,000 years in any place.

This means that no more than 8%, perhaps as little as 2%, of the Australian archaeological record covers the period of human-megafauna interaction. The “smoking gun” evidence of overkill should therefore be rare. Surovell and Grund show that the problem of finding such evidence is even worse than that, for two reasons.

First, when people first arrived their populations were necessarily small. Living sites therefore occurred at low density. As population size grew exponentially, site density increased. So, the very earliest sites must be far rarer than later ones.

But if overkill happened, populations of megafauna would have been going down as humans went up: as the density of sites was rising the proportion of them that could have contained evidence of megafauna kills was falling. Thus, sites with potential to preserve that evidence are actually a tiny proportion, perhaps much less than .01%, of the total archaeological record.

Second, material in archaeological sites degrades with time due to breakdown, weathering and scavenging of bone and removal by erosion. Old sites are eventually buried under sediments. The probability of discovering archaeological sites from the earliest occupation of Australia is intrinsically much lower than for later times, and most of the contents of those sites will have disappeared.

In fact, the very oldest archaeological sites in Australia typically contain only a few stone tools. They can tell us very little about interaction of the first Australians with any animals or plants, let alone reveal a picture of megafauna-killing.

Our fundamental task as scientists is to test hypotheses using evidence. To test the overkill hypothesis, we need a kind of evidence that would differ according to whether the hypothesis is true or false. Obviously, if overkill did not happen, evidence of megafauna-killing should be rare in the archaeological record. But, Surovell and Grund’s analysis makes it clear that if overkill happened, we should still expect evidence of killing to be rare. Therefore, failure to find such evidence does not amount to a test of the overkill hypothesis.

This does not mean that archaeological evidence of killing (or absence of such evidence) is useless in testing the overkill hypothesis. Surovell and Grund show it can be useful, by comparing the archaeological records of Australia, North America and New Zealand. All three places lost their megafaunas when people arrived, but this happened a very long time ago in Australia, and very recently (700 years ago) in New Zealand. North America is intermediate, with human arrival and extinction from 14,000 to 13,000 years ago.

Applying the same logic to all three cases, we predict that if overkill caused megafaunal extinction in each place the archaeological evidence of killing should be abundant in New Zealand, rare in North America, and vanishingly rare in Australia. That is exactly what we find.

There is so much evidence showing New Zealand’s moa were heavily hunted that nobody doubts overkill was the main cause of their extinction. In North America, there are undoubted kill sites for mammoths, mastodons and a few other species, but this evidence is far thinner than in New Zealand. Australian archaeology is yet to reveal any convincing evidence for megafauna-killing.

So, far from disproving overkill, the archaeological evidence from Australia is actually consistent with the overkill hypothesis.

About the Author

Christopher Johnson is an ecologist, interested in pure and applied ecology, environmental history, the biology of extinction, conservation and wildlife management. He is a Professor of Wildlife Conservation and ARC Australian Professorial Fellow at University of Tasmania.

Christopher Johnson receives funding from the Australian Research Council.

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

Birth of bling: world's first art studio found in South Africa

By Peter Hiscock

Could we have found the first artist’s studio in human history? We may well have.

We all recognise the material signs of wealth. Fast cars, large yachts and sparkling bling all tell us who has more. Crowns, insignia, mayoral gowns are material signs of rank or status.

Archaeologists have long pondered when these public displays of social difference first occurred. Emerging evidence suggests the antiquity of public symbolism is surprisingly great.

Bansky's Caveman, by Stefan Kloo (Lord Jim)
[Flickr, CC BY-2.0]

Indeed, the symbolism of social difference seems to have been present from the earliest period of our species existence. The rise of Homo sapiens may even have been linked to the use of public symbols.

Recent work in southern Africa, published today in Science, is helping archaeologists clarify the early history of painting and its use in creating symbols.

Discoveries at Blombos Cave

The latest discovery comes from Blombos Cave, a large cavern located on the southern African coast, south-east of Cape Town.

Location of Blombos Cave, archaeological site
[Vincent Mourre, Wikimedia Commons, CC BY-SA 3.0]

Here a team, led by Christopher Henshilwood of the University of Bergen and Francesco d’Errico from the Université de Bordeaux, has found a 100,000 year old artist’s workshop.

Excavations of the deep sediments piled up in the cave have regularly yielded surprising finds. Archaeologists have previously recovered standardised bone tools, perhaps awls, and delicately-shaped tools of stone projectile points dated to 70,000 years ago.

Henshilwood and his colleagues suggest these tools show ancient artisans were able to plan and create a sophisticated technology.

Even more revealing is the presence of ochre, natural iron-rich rock that can be ground into powder and used as paint. Archaeologists have long suspected pieces of ochre with abraded facets in those early times might indicate paintings of some kind, on rocks, wooden artefacts or even human bodies.

Since 70,000-year-old ochre slabs have geometric engravings on their surface, it is clear early humans were artistic, but until now archaeologists could not be sure they were painters.

The world’s first studio

Now Blombos has yielded new materials that reveal the earliest artist’s workshop.

In a layer 100,000 years old, Henshilwood excavated two containers, which are probably artist’s palettes or mixing-bowls, and associated tools.

Each palette or bowl is a large abalone shell containing a residue of ochre, burnt bone and other materials that had been ground up and combined with some fluid into a vibrant red paste.


One of these containers also contained a small grinding stone and a number of bone fragments that had been used to stir the paste.

The other container was associated with fragments of ochre, in this case red ferruginous siltstone, that had been abraded to create the red powder and the grinding stones on which they had been rubbed.

Henshilwood speculates that for a short period about 100 millennia ago, the site was used primarily as a workshop for preparing and using the paint mixtures.

Why paint?

Henshilwood and his team think this early painting workshop may be an example of artistic developments associated with the emergence of Homo sapiens.

The genetic evidence, as well as ancient skeletons that have been found demonstrate humans evolved in Africa and migrated across the globe in the last 70-100,000 years.

Some recent genetic studies have even suggested our species originated in southern Africa, possibly not far from Blombos.

Did the earliest modern humans develop a knowledge of chemistry that helped them invent painting?
Or does this workshop reflect the emergence of art itself, a behaviour that was carried forth by humans in their global dispersion?

Bifacial points, engraved ochre and bone tools discovered in Blombos Cave, c. 75-80,000 years old.
[Chris Henshilwood, Wikimedia Commons, CC BY-SA 3.0]

It turns out the evolution of art may have a very long history. Ochre has been found in far older African sites, dating back more than 300,000 years, as well as in Europe and the Middle East.

<< Learn more about Ochre in Paleolithic Burials in Origins >>

It’s been associated with hominids related, or ancestral, to us, such as Homo heidelbergensis and Homo neanderthalensis. If early hominids used ochre to colour themselves or their possessions then at least a basic form of painting had been present amongst hominids for several hundred millennia.

The artist’s workshop at Blombos 100,000 years ago is not the earliest use of ochre/paint but it represents a new intensity, a new scale, of artistry that may reflect a new role for painted public symbols.

This workshop was created near the start of the last Ice Age at a time when population size and resource availability changed.

In this context, signals of identity and differentiation perhaps assisted people to negotiate territory and trading relationships with neighbouring groups.

The Blombos discovery suggests the expression of social difference through painting was an important element in the development of modern culture.

We may well have found the beginning of a tradition that gave us Leonardo da Vinci, Rembrandt, Pablo Picasso, and, of course, Banksy.

For Further Reading

Henshilwood, C. S. et al. "A 100,000-Year-Old Ochre-Processing Workshop at Blombos Cave, South Africa." Science. 14 October 2011: Vol. 334 no. 6053 pp. 219-222. DOI: 10.1126/science.1211535

About the Author

Peter Hiscock is an archaeologist interested in the emergence and global dispersal of modern humans and long-term changes in their technology and social life. His research speciality is Australian prehistory and Palaeolithic technology; his research areas are France, Australia, and Africa.

Peter Hiscock receives funding from ARC. He is affiliated with the Australian National University.

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