Starting the era of the ground-based Mega Projects

Astronomers all over the world have a positive trait of working together to unravel the mysteries of the Universe. This is very good for the growth of knowledge. The increasing need for better observations of a certain kind causes Astronomy to have certain phases of growth. The past 3 decades saw a lot of advances in space-based technology & observations. While that continues, we are currently looking ahead to the next three decades which will see some of the most colossal fantasies of astronomers brought to life. We are now in the age of the Mega Projects!

Megaprojects are the next-generation of instruments that will offer the best resolution of the farthest objects and events in the Universe. These will be ground based, allowing detailed studies of subjects including planets around other stars, the first objects in the Universe, super-massive black holes in galaxies, and the nature and distribution of the dark matter. Some of the most ambitious and eagerly awaited Megaprojects are the Square Kilometer Array (SKA), the European Extremely Large Telescope (E-ELT) and the Thirty Meter Telescope (TMT).

The SKA is the highest priority future radio astronomy project. It is so big that it is being built on two continents, Africa & Australia! When fully deployed, it will consist of an array of ~ 4000 dishes and more than 10,000 antennae which will extend out to more than 3000 km from the central stations. Together they will have one million square metres (one square kilometer) of collecting area for radio waves. Its construction is set to start in 2018, with early science observations to be done in 2020.

In the same line are the fantastically large optical telescopes – the E-ELT & the TMT. The TMT was planned in the early 2000’s to be the world’s largest telescope, with its main mirror stretching 30 meters across! This mirror has been designed to be made of 492 smaller hexagonal 1.44 meter segments. Each of these segments will have the capacity of changing shape and position instantly in reaction to any detected change in the air column above the telescope – a marvel of adaptive optics. It is currently to be put on the Mauna Kea peak in the Hawaii islands of the USA. This 2000 ton behemoth could be a powerful complement to the James Webb Space Telescope in tracing the evolution of galaxies and the formation of stars and planets, among many other astrophysical problems it will investigate.

The E-ELT will however be made 39 meter (made of 798 smaller segments) in diameter and will end up as the largest optical telescope on Earth. It was first dreamt of as an enormous 100 meter telescope, but the feasibility for that was not good. Construction of the E-ELT got underway in 2004 in Cerro Armazones, Chile. Both these cousins will probably see the first light close to 2025. As has been the case for every previous increase in capability of this magnitude, it is very likely that the scientific impact of TMT & E-ELT will go far beyond what we envision today and they will enable discoveries that we cannot anticipate.

These Megaprojects are immense in scale and all cost above a billion US dollars. For example, the TMT site covers about 5 acres and the telescope has an estimated price of $1.4 billion. It may not be possible for one institute or even a country to undertake such a project on its own. However, several governments have taken progressive steps to support collaborative Astronomy projects to create these instruments. TMT is thus a joint international venture involving the USA, Japan, China, India and Canada. The E-ELT is the brainchild of the ESO, the European organisation for Astronomical research in the Southern Hemisphere, which is an inter-governmental organisation supported by 16 Member States, along with the host state of Chile. Similarly, with support from 11 member countries the SKA will bring together some of world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope.

Thus the Mega Projects also provide collective benefits to the community. They will help develop a new confidence in a next generation of scientists and engineers of successfully delivering something revolutionary and of international stature. All member countries can take pride in them and hence have a favourable attitude towards other fields of Science research as well.

All these telescopes, along with several of their smaller cousins that are coming up too, will be very popular among people. The next-generation technology will need the next-generation of students to be trained to use these. Hence the prospect for using these inspiring projects as case examples for education and public outreach are enormous everywhere in the world. All those who are involved in Astronomy EPO activities need to take note of these. It is time to start planning how to celebrate each phase of the construction & use of these big leaps of Humanity towards knowing more about our Universe.

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Samir Dhurde is in-charge of the popular outreach programme - SciPop, of the Inter-University Centre for Astronomy & Astrophysics (IUCAA) in Pune, India. His is also part of the TMT Workforce Pipeline, Education, Public Outreach and Communications (WEPOC) advisory group. Outreach at the IUCAA Children’s Science Exploratorium is his day & evening job, but he is a Radio Astronomer in his free time. Being involved in several national campaigns in India, aimed at taking science to everyone through very simple methods, he loves travelling to reach the remotest people of his vast and beautiful country.

An Australian Space Policy

Australia is a user of space. We consume it. We've done so for a very long time and we are very good at it. There are some people (myself included) that really think Australia should take a few steps beyond this relationship we have with space, the international space industry and space based technologies. We have a lot people working on space in Australia and we are renowned worldwide for our contributions and ingenuity.

This blog post is what I think an Australian space plan should look like.

This plan has been developed to take the best ideas from the Australian Academy of Science (AAS) National Committee for Space Science (NCSS), who have studied it, and who know how best Australia can be a part of it.

The three main ideas are:

1. Adopt expert recommendations of the Decadal Space Plan from the National Committee for Space Science.
2. Create an Australian Space Agency, ASTRA
3. The Woomera launch facility

1. The Decadal Plan
The plan's vision is ‘Build Australia a long term, productive presence in Space via world-leading innovative space science and technology, strong education and outreach, and international collaborations’. The plan has 14 recommendations with five key imperatives in mind:

• Enable Australia to develop a strong space industry, and offset the risks of depending primarily on foreign space capabilities.
• Position Australians to solve major scientific and technological problems.
• Actively nurture, coordinate, and manage Australia’s investment in space science.
• Leverage increased public investment in space science.
• Provide government, community and business with the information needed to guide investment in space science and technology.

The plan document outlines the importance and current status of space science in Australia, and the specific scientific goals of the Australian space science community the next decade and build on our strengths.

With a very large group of experts in their field of astronomy and space science, and a sizeable group of experts from industry and business. I would like Australia to be a place that is known for not only its innovation with existing space based technologies but also an innovator in the field and a provider of world class facilities and programs.

The decadal plan seeks to establish government, commercial, industry and public collaborations to better develop and strengthen our niche technologies in order to be a contributor to the international space industry.

There's even a cheeky reference to creating Australia's own space agency (like NASA) in the plan. I'd like to go that extra step and I'll come to that now.

2. ASTRA: Australia’s Space Agency
ASTRA (Australian Space Technology & Research Agency) will serve many purposes including:

• Developing a strong, internationally recognised, Australian space capability.
• Create partnerships of Australian and international government and private stakeholders such as NASA, CSA, ESA,JAXA and SpaceX for example.
• Provide strong economic, educational, government, and strategic benefits to Australia.
• Provide structure for further research into space and space-based technologies.

Space provides exciting opportunities for humanity to advance itself. Technological development occurring in space research and related fields has already provided us with new technology in the fields of communication, transportation, energy, physics and biology as well as some amazing spin-offs from space-based technologies. Some of these technologies are used regularly by people all over the world.

I think that Australia has the potential to be a hub of space investment and technological development. To do so, however, would require Australia to make serious plans to invest in space research domestically and to attract investment from abroad. Establishing ASTRA will allow us to collaborate with the other major space agencies (and not major ones) around the world and start becoming a part if the conversation and benefit from those membership.

3. Woomera Launch Facility
Australia’s launch facility at Woomera in South Australia will once again become world leading, open to governments and commercial groups wanting to use the facility.

The conditions are perfect for this redevelopment (images of the phoenix rising out of the ashes are invoked here!) due to recent technological developments in the space industry such as reusable launch vehicles that would benefit greatly from a vast area to land.

The Woomera Launch facility is a largely flat, featureless, quiet electromagnetic and vast terrain of 124 000 km2 the largest landlocked range in the world, approximately the size of England, which allows easier access for test object recovery (an important safety feature for launch activities). Rainfall is rare, and the climate is generally warm and dry. The stable conditions virtually assure the ability to conduct year-round operations, with little downtime.

Although Woomera isn’t as close to the equator as some launch sites, (the issue being the further from the equator you are the more speed, or delta-v, you need to get to the right orbit) this is out weighed by the fact that a launch can almost be guaranteed and launch insurance considerations, time and costs will dramatically decrease.

The town of Woomera, meaning spear thrower, is perfect for redevelopment into a support community for the launch facility with heavy influence from Industry, instrumentation, education & research, technologies and services. You have heard of charter cities, well Woomera would be a perfect candidate for that!

Conclusions
Australia is currently a user of space and space based technologies. We have good relationships with countries that have big and exciting space plans and projects and we let them spend their money on those things. However, I think believe our chance and indeed our duty to become a formal member of that group has arrived. We too must spend our money, and of course reap the benefits of that investment into the future!

Technologies are moving so fast, and although we contribute to the efforts and have some world class researchers and industries here, there is a chance to gain some national benefits from actively contributing and supporting the international space industry with our resources, expertise, facilities and ingenuity.

With such an impressive number and quality of experts in their fields and in the space industry, it is imperative that we listen to them and trust their evidence backed advice and recommendations. This, together with some future thinking and planning, Australia’s place in the space industry will be worthwhile and beneficial.

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Tom Gordon is a science communicator at the School of Physics. My role is to provide and develop outreach programs to, mainly, High school students in order to assist them with their studies, provide mentors and information about University life and expectations. In addition, I run many other School and holiday programs such as Gifted and Talented workshops and I am the Chair of the School of Physics outreach committee.

My role also extends to media enquiries and publications, as well as in-reach to current university students as well as Science Teachers workshops and forums.

I did my degree in Astronomy and Astrophysics as well as a Graduate Diploma in Science Communication at the ANU, then a Masters Degree in Space Studies in France. After returning to Australia he was a High School teacher for 4 years in Sydney, and a stint at the National Measurement Institute as a legal metrology policy officer.

In my *spare* time I am on the executive of the Parents and Citizens committee and my daughters' school and I have also become involved and very interested in the Australian Political process by joining and being active in a minor political party.

Exploring the Intersections of Astronomy and Culture

When the average person thinks of astronomy, images of the solar system, planets, stars and galaxies come to mind. Breathtaking photos such as the Hubble Deep Space field or the view of Earth from Saturn taken by the Cassini spacecraft. Many people think that astronomy is all about “out there” and doesn’t have much to do with people here on Earth. But the truth is that astronomy and culture are inextricably intertwined and have been so since people first started looking up at the sky in wonder.

There are hundreds of examples of ancient sites built thousands of years ago all around the world in which people created monuments, temples, tombs and other structures that were aligned with the Sun, Moon or stars. Ice age cave paintings in France show evidence of observations of the Moon. The megalithic stones at Stonehenge in England are aligned with the rising and setting points of the Sun at summer and winter solstice, providing a ritual space that is tied to the solar calendar. Air shafts in Egypt’s Great Pyramid tomb are aligned to stars that symbolize key mythological concepts related to death and resurrection.

These are all examples of archaeoastronomy sites. Archaeoastronomy is the study of how people (generally in the past) have observed and understood phenomena in the sky and how this understanding was embedded in their culture. By its nature, archaeoastronomy is interdisciplinary. The word itself comes from a combination of archaeology and astronomy, but the academic field also draws on cultural anthropology, history of astronomy, art history, epigraphy, religion and more.

Whereas archaeoastronomy generally focuses on cultures in the past, ethnoastronomy explores how contemporary cultures understand, use and connect to the sky. The focus here is not on ancient people from long ago, but living people who are using celestial knowledge today. An example of ethnoastronomy is the solar symbolism of religious rituals performed by indigenous Maya people in the highlands of Mexico.

In many ways, ethnoastronomy implies an “other.” It often takes the form of the study of non-Western peoples by Western scholars. From my perspective, this can result in biases on how ethnoastronomy is conceptualized and defined. For example, the use of the Moon’s phases to determine the dates of Easter is often not considered ethnoastronomy, but the use of the Moon’s phases to determine planting and fishing in Hawaiian culture would be considered ethnoastronomy by many. Partly for this reason, I sometimes use the phrase “cultural astronomy” to refer to the ways in which astronomical knowledge is embedded into culture, both in the past and in contemporary societies. To me, this feels broader, more inclusive and a little less academic.

Whether called archaeoastronomy, ethnoastronomy or cultural astronomy, interest in the intersections between astronomy and culture is growing, as evidenced by the UNESCO-IAU Astronomy and World Heritage Initiative. Created in2003, this international initiative aims to “establish a link between science and culture towards recognition of the monuments and sites connected with astronomical observations dispersed throughout all the geographical regions, not only scientific but also the testimonies of traditional community knowledge”.

But “cultural astronomy” could be understood another way. Thinking more broadly, the intersection of astronomy and culture is seen in such projects as the Exploratorium’s Science for Monks project which engaged Tibetan Buddhist monks in science, including astronomy. The mission of this project is to grow and sustain science learning that engages Buddhism with science. The monks’ unique perspective on science and spirituality includes such compelling questions as “If scientists are able to find exoplanets with life on them, what plans and preparations have we done to help/benefit beings on those planets?”

Another example of the intersection of astronomy and culture can be seen in the Native Skywatchers project which shares star and constellation stories from the Lakota and Ojibwe cultures. These stories were traditionally only told at certain times of the year but as elders pass away, knowledge about the sky threatens to go with them. In this case, sharing knowledge about the sky is a way of keeping cultural heritage alive.

Not all interactions between astronomy and culture are harmonious. As I write this (in April 2015), there are many Native Hawaiian people who are actively protesting the construction of the Thirty Meter Telescope on Mauna Kea in Hawaii. For astronomers, Mauna Kea is one of the best places in the world to conduct astronomical research because of its latitude, altitude, stable atmosphere, relative lack of light pollution, etc. However, Mauna Kea is also one of the most sacred places in Hawaii so building a huge telescope on this mountain is akin to tearing down Notre Dame Cathedral in France to install scientific instruments in its place.

For those readers who are interested in exploring more cultural astronomy topics, here are some resources for you to check out:

• Cultural Astronomy podcast series on 365 Days of Astronomy
• NeverLost website exploring Polynesian Voyaging
• Traditions of the Sun website exploring Chaco Canyon and Yucatec Maya solar sites
• Living Maya Time website exploring Maya calendars
• Calendar in the Sky website which connects the knowledge of the Maya to NASA science

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Nancy Alima Ali, M.Ed., is a Coordinator of Public Programs at Multiverse at the Space Sciences Lab at the University of California, Berkeley. For over 15 years, Ms. Ali has been active in both formal and informal education as a classroom teacher, college instructor, museum educator, curriculum developer and program manager. Ms. Ali has a particular interest in exploring the ways in which multiple worldviews contribute to our understanding of the cosmos. She blogs about the intersection of astronomy and culture at www.astroalima.com and hosts the Cultural Astronomy podcast series on 365 Days of Astronomy at https://cosmoquest.org/x/365daysofastronomy/meet-our-podcasters/cultural-astronomy/.

Occultations by Pluto – Exploring Climate Change on a Distant World

Occultations in the Solar system

Solar and lunar eclipses are spectacular events. Similar situations occur regularly when exoplanets move in front of their host star. Our own Moon blocks the light of many of stars at any time. The other planets are much further away and occult much fewer stars. Occultations of bright stars by the dwarf planet Pluto occur only every few years, because of Pluto’s small size and its large distance from the Earth. By carefully looking at the dimming of the starlight during such an event, it is possible to derive physical properties of Pluto and its atmosphere.

Pluto was discovered in 1930. Its orbit is eccentric, with a distance varying between 30 and 50 AU from the Sun, and an orbital period of almost 250 years. Pluto has never been visited by spacecraft, and many of its properties are still a mystery. Among the few methods available to learn more about Pluto are occultations. Pluto is now much closer than at the time when it was discovered. Pluto was at its closest distance in 1989 and therefore easier to study, leading to the discovery of its moon Charon, and of Pluto’s thin atmosphere. Pluto is now gradually moving further away, and we have to wait until the year 2237 until the next closest approach occurs.

Occultation events involving Pluto

When Pluto is predicted to occult a relatively bright star, observatories from all over the world are ready to record the phenomenon. An occultation recent event of great interest was the double transit on 23 June 2011, where both Pluto and Charon both occulted the star 2UCAC24677089. Astronomers obtained a stellar light curve of event from Hawaii. The light curve shows two strong dips in the luminosity. The first dip comes from Charon, which does not have an atmosphere. Charon moved in front of the star and blocked all starlight for ~45 seconds.

Pluto is responsible for the second dip, ten minutes later. As compared to the Charon’s dip, there are three differences: (i) Pluto blocks at most 65% of the starlight, (ii) the occultation lasts longer, and (iii) the dip does not have a rectangular shape, but is much smoother. Pluto moved at a slightly different path across the sky, and covered slightly more than 65% of the star’s surface. As Pluto is larger than Charon, the occultation took longer: ~80 seconds. Finally, the smooth shape of the curve provides clear evidence that Pluto has an atmosphere. At high altitudes the atmosphere blocks little starlight, while the denser atmosphere near the surface blocks more light. By studying the light curve it is possible to derive the atmospheric pressure at different altitudes above Pluto’s surface, without actually seeing it directly.

The combined occultation event on 23 June 2011 took about twelve minutes, and therefore required precise timing. The duration is determined by both the orbital velocity of Pluto (~17,000 km/hour), and the velocity of the observers on Earth, with orbit the Sun at ~110,000 km/hour. Not only time, but also location is crucial for observers: the occultation was only observable the North Pacific Ocean. Fortunately, Hawaii has plenty of telescopes that could be used to observe this rare event. The mobile SOFIA airborne observatory was also able to catch the event.

Climate change on Pluto

Pluto has been known to have an atmosphere for decades, so why detect the atmosphere again? The reason is climate change: Pluto’s orbit is eccentric, and the amount of sunlight received varies by almost a factor three. Pluto was at perihelion in 1989 and is now gradually getting colder, which affects its atmosphere. Pluto’s surface can become so cold that nitrogen gas freezes out on its surface, as it gets colder.

By comparing all available measurements from 1988 to 2013, astronomers discovered that the changes in Pluto’s atmosphere were smaller than previously thought. Surprisingly, the atmospheric pressure even seemed to increase, which was the opposite of what models predicted. The solution is quite tricky, and is related to Pluto’s obliquity: it orbits on its side. Pluto’s North :ole contains a large nitrogen ice cap. This North Pole was in permanent shadow during perihelion in 1989. Now that Pluto has moved away from perihelion, the North Pole is gradually exposed to sunlight, and the polar cap starts to evaporate. This increases atmospheric pressure, until Pluto moves too far away from the Sun, after which the nitrogen freezes out on the South pole. This cycle will repeat itself as Pluto continues to orbit around the Sun.

Future prospects

Although occultation events involving Pluto are rarely observable, they continue to provide relevant data, and are currently the only way to study Pluto’s atmosphere. This will change later this year when NASA’s New Horizons Spacecraft arrives at Pluto. The spacecraft does not have enough fuel left to slow down, so it only spends a few days near Pluto. Nevertheless, it will be the first spacecraft ever to visit the dwarf planet, and is bound to make many new discoveries!

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Thijs Kouwenhoven is a research professor at the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University in China. He grew up in the Netherlands, where he obtained his undergraduate degree at Leiden Observatory and his PhD degree at the University of Amsterdam, after which he spent several years as a researcher at the University of Sheffield (UK). His research interests include planetary systems dynamics, the formation and evolution of star clusters, and binary/multiple stellar systems.