Cosmic Vertigo

I'm pleased to announce the LAUNCH of my new space podcast, Cosmic Vertigo, made with co-host Alan Duffy and our amazing producer Joel Werner.

"Do you ever feel dizzy when you think about the incomprehensible scale of space? We call that feeling Cosmic Vertigo. Welcome to a head-spinning conversation between two friends who study the sky for a living."

Rest state: Alan and I cracking up (Photo: ABC/Radio National)

The three of us had a lot of fun creating this series, and I'm in awe of Joel's editing and production genius.

Dream Team: Alan Duffy, Joel Werner, and yours truly (Photo: ABC/Radio National)

The first two episodes are now LIVE with a new one released every two weeks.... so GO LISTEN and COMMENT and SUBSCRIBE wherever you get your podcasts!

Five things we know about the universe that will make you feel very small

Here is an article I contributed to ABC Science, originally posted here.

Five things we know about the universe that will make you feel very small.

One thing we know about the universe is that it's really big. Another is that thinking about it and trying to understand it will make your brain hurt.

Astronomer Amanda Bauer takes us through her top five mind-expanding things we know (or don't know) about the universe.

1. There is no edge of the universe

PHOTO: Full-sky map of the oldest light in the universe (NASA/WMAP Science Team)

There is one edge we know of - our horizon, which is the limit of how far we can see.

Imagine sailing on a boat on the ocean and seeing a horizon in the distance, past which you know there is more Earth, but you just can't see it. We've measured the universe to be flat (as opposed to curved like Earth or saddle-shaped), but our horizon exists because of the finite speed of light.

Beyond that visible horizon, we think the universe just keeps going in the same way - forever.

We have no reason to believe there is an edge. But we also have no way of measuring this infinity because we physically cannot see it.


2. Dark matter and dark energy make up 95 per cent of the universe

PHOTO: A composite image showing the galaxy cluster 1E 0657-56, better known as the bullet cluster. Gravitational lensing was used to locate the dark matter (shown as blue patches) in these two colliding galaxies. The pink colour shows gas blown apart by the collision. (NASA/Chandra X-Ray Observatory)

Only 5 per cent of the universe is made of ordinary material like planets, stars, cars, and coffee. This "normal matter" is made mostly of protons, neutrons, and electrons.

Another 24 per cent is an exotic material that interacts through gravity, but produces no light, making it invisible to us. We call this "dark matter".

While dark matter only interacts with normal matter very weakly, particle physicists have plausible candidates for what dark matter is.

Hopefully particle accelerators like the Large Hadron Collider will provide more insight for scientists very soon.

That brings us to the final 71 per cent of the stuff in the universe, which is a truly bizarre type of matter. Perhaps it's not matter at all, but a property of the universe itself. We call this mysterious stuff "dark energy".

What we do know is that dark energy has a gravitationally repulsive effect that is causing the expansion of the universe to speed up. But we don't understand how this acceleration is happening.


3. There is no centre of the universe

PHOTO: In a way, we're all at the centre of our own universe. (NASA/Ames/JPL-Caltech)

The universe has been expanding ever since the Big Bang 13.8 billion years ago.

But the Big Bang should not be imagined as a normal explosion in space. Rather, the Big Bang is an explosion of space itself, so that every point in space expands equally away from every other point in space. There is no centre to the expansion.

From our galaxy we measure that all galaxies are moving away from us, and the farther the galaxy, the faster away it is moving.

The interesting thing is that if you zoomed off to any other galaxy in the universe, you would measure the exact same effect - all other galaxies would be moving away from you.

In this way, you could argue that you are the centre of the universe. But then, so is everyone else.


4. Far-away galaxies offer a glimpse into the past

PHOTO: At 3 million light years from Earth, the Triangulum galaxy is even further away than Andromeda, so gives us a glimpse even further back in time. (NASA)

When we look at distant galaxies, we are actually looking at a snapshot of the past.

Some galaxies are located so far away their light takes billions of years to reach us, even travelling at the speed of light. The images we collect through our telescopes tell us what the galaxies looked like billions of years ago, when the light left the galaxy.

Andromeda is the nearest spiral galaxy to our Milky Way. It floats at a distance of 2.5 million light-years, so the views we capture of Andromeda show us what it looked liked 2.5 million years ago. And that's the closest spiral galaxy.

The farthest galaxy we have detected is 13 billion light years away. This means we are looking at galaxy light as it was only 2 billion years after the Big Bang.

We will never capture light from the future though, only the distant past.


5. The future will be dominated by black holes

PHOTO: Pretty much all galaxies have a supermassive black hole at their centre. This one, a spiral galaxy known as NGC 4258, also has two unusual spiral arms that glow in X-ray, shown in purple. (ASA/CXC/JPL-Caltech/STScI/NSF/NRAO/VLA)

We are currently in the Stelliferous Era - meaning the universe has a lot of stars. This era began a few hundred million years after the Big Bang when the very first stars formed.

Now, almost 13.7 billion years later, new stars continue to form, although the number of new stars forming each year is dropping.

Eventually, new stars will stop forming and all stars will slowly burn out. But in that very distant future, supermassive black holes will still thrive.

It's believed that nearly every galaxy in the universe has a supermassive black hole at its centre, which means that eventually hundreds of billions of supermassive black holes will be spread throughout our ever-expanding universe.

Over trillions and trillions and trillions, and many more trillions, of years these black holes will slowly evaporate through Hawking Radiation.

The leftover elementary particles will be left to zoom through a vast, cold space with nothing much around to bump into.

Sounds very empty.

Cloudy with a chance of life: how to find alien life on distant exoplanets

This article was originally published in The Conversation on on 26th November 2015.

Cloudy with a chance of life: 

how to find alien life on distant exoplanets

by Brad Carter, Amanda Bauer, & Jonti Horner

How do you go about hunting for life on another planet elsewhere in our galaxy? A useful starting point is to imagine looking from afar for signs of life on Earth. In a telescope like those we have on Earth, those aliens would likely just see the Earth and sun merged together into a single pale yellow dot.

If they were able to separate the Earth from the sun, they’d still only see a pale blue dot. There would be no way for them to image our planet’s surface and see life roving upon it.

However, those aliens could use spectroscopy, taking Earth’s light and breaking it into its component colours, to figure out what gases make up our atmosphere. Among these gases, they might hope to find a “biomarker”, something unusual and unexpected that could only be explained by the presence of life.

On Earth, the most obvious clue to the presence of life is the abundance of free oxygen in our atmosphere. Why oxygen? Because it is highly reactive and readily combines with other molecules on Earth’s surface and in our oceans. Without the constant resupply coming from life, the free oxygen in the atmosphere would largely disappear.

Biomarkers

But the story isn’t quite that simple. Life has existed on Earth for at least 3.5 billion years. For much of that time, however, oxygen levels were far lower than those seen today.

And oxygen alone is not enough to indicate life; there are many abiological processes that can contribute oxygen to a planet’s atmosphere.

The concentration of oxygen in the Earth’s atmosphere over the last billion years. As a reference, the dashed red line shows the present concentration of 21%.  Wikimedia

For example, ultraviolet light could produce abundant oxygen in the atmosphere of a world covered with water, even if it was devoid of life.

The upshot of this is that a single gas does not a biomarker make. Instead, we must instead look for evidence of a chemical imbalance in a planet’s atmosphere, something that can not be explained by anything other than the presence of life.

Here on Earth, we have one: our atmosphere is not just rich in oxygen, but also contains significant traces of methane. While abundant oxygen or methane could easily be explained on a planet without life, we also know that methane and oxygen react with each other strongly and rapidly.

When you put them together, that reaction will cleanse the atmosphere of whichever is least common. So to maintain the amount of methane in our oxygen-rich atmosphere, you need a huge source of methane, replenishing it against oxygen’s depleting influence. The most likely explanation is life.

Observing exoplanetary atmospheres

If we find an exoplanet sufficiently similar to our own, there are several ways in which we could study its atmosphere to search for biomarkers.

When a planet passes directly between us and its host star, a small fraction of the star’s light will pass through the planet’s atmosphere on its way to Earth. If we could zoom in far enough, we would actually see the planet’s atmosphere as a translucent ring surrounding the dark spot that marks the body of the planet.

How much starlight passes through that ring gives us an indication of the atmosphere’s density and composition. What we get is a “transmission spectrum”, which is an absorption spectrum of the planetary atmosphere, illuminated by the background light of the star.

Our technology has only now become capable of collecting and analysing these spectra for the first time. As a result, our interpretation remains strongly limited by our telescopic capabilities and our burgeoning understanding of planetary atmospheres.

Despite the current challenges, the technique continues to develop with great success. In the past few years, astronomers have discovered a wide variety of different chemical species in the atmospheres of some of the biggest and baddest of the known transiting exoplanets.

Many exoplanets may have no atmosphere at all. NASA/JPL-Caltech

Eclipses

Another approach involves observing a transiting planet and its star as they orbit one another. The goal here is to collect some observations when the planet is visible (but not in transit), and others when it is eclipsed by its star.

With some effort, astronomers can subtract one observation from the other, effectively cancelling the hugely dominant contribution of light from the star. Once that light is removed, what we have left is the day-side spectrum of the planet.

[Star + Planet] - [Star] = [Planet] NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

The future

Astronomers are constantly developing new techniques to glean information about exoplanetary atmospheres. One that shows particular potential, especially for the search for planets like our own, is the use of polarised light.

Most of the light we receive from planets is reflected, originating with the host star. The process of reflection brings with it a subtle benefit - the reflected light gains a degree of polarisation. Different surfaces yield different levels of polarisation, and that polarisation might just hold the key to finding the first oceans beyond the solar system.

By rotating a polarising filter, we can block light of certain polarisation. This is how polarised sunglasses cut the glare from puddles and the ocean on a sunny day.  Wikimedia, CC BY-SA

These methods are still severely constrained by two factors: the relative faintness of the exoplanets, and their proximity to their host star. The ongoing story of exoplanetary science is therefore heavily focused on overcoming these observational challenges.

Further down the line, advances in technology and the next generation of telescopes may allow the light from an Earth-like planet to be seen directly. At that point, the task becomes (slightly) easier, in part because the planet can be observed for far longer, rather than just relying on eclipse/transit observations.

But even then, spectroscopy will be the way to go; the planets will still be just pale blue dots.

What we have seen so far

The exoplanets we have discovered to date are highly inhospitable to life as we know it. None of the planets studied so far would even be habitable to the most extreme of extremophiles.

The planets whose atmospheres we have studied are primarily “hot Jupiters”, giant planets orbiting perilously close to their host stars. As they skim their host’s surface, they whizz around with periods of just a few days, yielding transits and eclipses with every orbit.

Because of the vast amounts of energy they receive from their hosts, many of these “hot Jupiters” are enormous, inflated far beyond the scale of our solar system’s largest planet. That size, that heat and their speed, make them the easiest targets for our observations.

But as our technology has improved, it has also become possible to observe, through painstaking effort, some smaller planets, known as “super-Earths”.

Atmospheres of distant planets…

The hot Jupiter HD189733 has one of the best understood planetary atmospheres beyond the solar system.

Artists impression of the broiling blue marble, HD 189733 b. NASA, ESA, M. Kornmesser

Observations by the Hubble Space Telescope, in 2013, suggest a deep-blue world, with a thick atmosphere of silicate vapour. Other studies have shown its atmosphere to contain significant amounts of water vapour, and carbon dioxide.

Overall, however, it appears to be a hydrogen-rich gas giant like Jupiter, albeit super-heated, with cloud tops exceeding 1,000 degrees. Beneath the cloud turps lies a widespread dust layer, featuring silicate and metallic salt compounds.

The young giant planets in the HR8799 system appear to have hydrogen-rich but complex atmospheres, with compounds such as methane, carbon monoxide and water. They are likely larger, younger, and hotter versions of our own giant planets - with their own unique subtleties.

A direct image of the four planets known to orbit the star HR 8799. Ben Zuckerman

For the super-Earth GJ1214b the lesson is to be careful about making conclusions. Early suggestions that this might be a “water world” or have a cloudless hydrogen atmosphere have since been superseded by models featuring a haze of hydrocarbon compounds (like on Titan), or grains of potassium salt or zinc sulphide.

While the search for Earth-like planets continues using ground- and space-based telescopes, exoplanetary scientists are eagerly awaiting the launch of the James Webb Space Telescope JWST.

That immense telescope, scheduled for launch in around October 2018, could mark the true beginning of the exciting search for distant atmospheric biomarkers and exoplanetary life.

seeing the universe through spectroscopic eyes

I published this article at The Conversation last week, reproduced here for your enjoyment :) Original article link. 


Seeing the Universe Through Spectroscopic Eyes

When you look up on a clear night and see stars, what are you really looking at? A twinkling pinprick of light with a hint of colour?

Imagine looking at a starry sky with eyes like prisms that separate the light from each star into its full rainbow of colour. Astronomers have built instruments to do just that, and spectroscopy is one of the most powerful tools in the astronomer’s box.

The technique might not produce the well-known pretty pictures sent down by the Hubble Space Telescope, but for astronomers, a spectrum is worth a thousand pictures.

Visible spectra reveal huge amounts of information about objects in the distant cosmos that we can’t learn any other way.

So what is spectroscopy?

Spectroscopy is the process of separating starlight into its constituent wavelengths, like a prism turning sunlight into a rainbow. The familiar colours of the rainbow correspond to different wavelengths of visible light.

The human eye is sensitive to the visible spectrum – a narrow range of frequencies among the entire electromagnetic spectrum. The visible spectrum covers wavelengths of roughly 390 nanometers to 780 nanometers (astronomers often use units of Angstroms (10-10), so visible light spans 3,900 to 7,800 Angstroms).

Once visible starlight reaches the curved primary mirror of a telescope, it is reflected toward the focal point and can then be directed anywhere. If the light is sent directly to a camera, an image of the night sky is seen on a computer screen as a result.

If the light is instead sent through a spectrograph before it hits the camera, then the light from the astronomical object gets separated into its basic parts.

A very simple spectrograph was used by Issac Newton in the 1660s when he dispersed light with a glass prism. Modern spectrographs consist of a series of optics, a dispersing element and a camera at the end. The light is digitised and sent to a computer, which astronomers use to inspect and analyse the resulting spectra.



The video (above) shows the path of distant starlight through the 4-metre Anglo-Australian Telescope (AAT) and a typical spectrograph, revealing real data at the end.

What do spectra teach us?

A spectrum allows astronomers to determine many things about the object being viewed, such as how far away it is, its chemical makeup, age, formation history, temperature and more. While every astronomical object has a unique rainbow fingerprint, some general properties are universal.

Top shows a spiral galaxy spectrum. Bottom shows non-star-forming galaxy spectrum.
Screenshot from Australian Astronomical Observatory video above

Here we examine the galaxy spectra shown in the video. The spectrum of a galaxy is the combined light from its billions of stars and all other radiating matter in the galaxy, such as gas and dust.

In the top spectrum you can see a few strong spikes. These are called “emission lines” and occur at discrete wavelengths due to the atomic structure of atoms as electrons jump between energy levels.

The hydrogen spectrum is particularly important because 90% of the normal matter in the universe is hydrogen. Because of the details of hydrogen’s atomic structure, we recognise the strong hydrogen-alpha emission line at roughly 7,500 Angstroms in the top spectrum image.

In a galaxy, only the youngest, biggest stars are hot enough to excite surrounding hydrogen gas enough that the electrons populate the third energy level, before falling to the second lowest, thus emitting a hydrogen-alpha photon.

Because of this, we know the strength of the hydrogen-alpha line in a galaxy’s spectrum indicates how many very young stars there are in the galaxy. Since the bottom spectrum shows no hydrogen-alpha emission, we can conclude that the bottom galaxy is not sparking new life in the form of shining stars, while the top galaxy harbours several hard working stellar nurseries.

In the bottom spectrum you can see a number dips. These are called “absorption lines” because they appear in the spectrum if there is anything between the light’s source and the observer on Earth absorbing the light. Absorbing material could be the extended layers of a star or interstellar clouds of gas or dust.

The absorption lines close to each other below 5,000 Angstroms in the bottom spectrum are the calcium H and K lines and can be used to determine how quickly stars are zooming around the galaxy.

In a galaxy how far away?

A basic piece of information derived from a spectrum is the distance to the galaxy, or specifically, how much the light has stretched during its journey to Earth. Because the universe is expanding, the light emitted by the galaxy is stretched toward redder wavelengths as it innocently moves across space. We measure this as redshift.

To determine the exact distance of a galaxy, astronomers measure the well-studied pattern of absorption and emission lines in the observed spectrum and compare it to the laboratory wavelengths of these features on Earth. The difference tells how much the light was stretched, and therefore how long the light was travelling through space, and consequently how far away the galaxy is.

The absorption lines ‘shift’ the farther away an object is, giving us an indication of its distance from us.
Georg Wiora (Dr. Schorsch)

In the top galaxy spectrum mentioned earlier, we measure the strong red emission line of hydrogen-alpha to be at a wavelength of roughly 7,450 Angstroms. Since we know that line has a rest wavelength of 6,563 Angstroms, we calculate a redshift of 0.13, which means the light was travelling for 1.7 billion years before it reached our lucky telescope. The galaxy emitted that light when the universe was roughly 11.8 billion years old.

Australia’s strength in spectroscopy

Australia has led the way internationally for spectroscopic technology development for the last 20 years, largely due to the use of fibre optics to direct galaxy light from the telescope structure to the spectrograph.

A huge advantage of using optical fibres is that more than one spectrum can be obtained simultaneously, drastically improving the efficiency of the telescope observing time.

Australian astronomers have also led the world in building robotic technologies to position the individual optical fibres. With these, the AAT and the UK Schmidt Telescopes (both located at Siding Spring Observatory in New South Wales) have collected spectra for a third of all the 2.5 million galaxy spectra that humans have ever observed.

While my own research uses hundreds of thousands of galaxy spectra for individual projects, it still amazes me think that each one of these spectra are composite collections of light created by hundreds of billions of stars gravitationally bound together in a single swirling galaxy, many similar to our own Milky Way home.

discovering pluto

later today, the new horizons space craft will fly by pluto at a distance of only 12,500 km - its closest approach is about 1 earth away.   that's incredible!

this mission has already given us way better views of the dwarf planet than we've ever achieved (even with hubble).  what will the new data tell us?  what does the surface looks like? (are there craters? ice? cracks? plumes? mountains?)  what is the atmosphere is made of? (methane, nitrogen, and what else?) does its surface ice turn to gas during different seasons and then does it get released to space?

ultimately, we want to understand what the objects way out in the kuiper belt are made of because they can tell us how all the other planets and the entire solar system was formed.

Created by Alex Parker with NEW images of pluto!

new horizons cannot send data back at the same time it is taking images, so it is following an automatic program, written by the engineers and astronomers, to maximize its data collection during the flyby.  we will receive the first message and prelim images tomorrow (july 15th, 2015 - it takes 4.5 hours for the data to reach earth).  cant wait!

then new horizons will start sending data back to us over the next ~16 months as it flies away out into the depths of the kuiper belt at the outskirts of our solar system.

i'm excited.

i talked (enthusiastically) to Patricia Karvelas on radio national's drive program last friday about pluto and what to expect from this flyby. you can LISTEN HERE.

it also seems like the perfect time to break out this old number: pluto, the previous planet :)

Pluto, the previous planet from carolune on Vimeo.

dirty space news update

here are a few pieces of dirty space news that i've collected recently, all together in one happy place for your enjoyment.

from a paper simulating magnetic fields called "High Energy Neutrino Emission from Astrophysical Jets in the Galaxy."  i particularly like the last line of the abstract: "One of the main ingredients of the present work is the presence of a toroidal magnetic field that confines the jet flow and furthermore greatly affects the distribution of the high energy neutrinos." 

Caption from paper: A plot of the magnetic field magnitude roughly half way into the simulation. We can see the jet self-confinement due to magnetic forces resulting in a narrow beam.

Adrian Price-Whelan on twitter shared a graph he created for his research and wondered "maybe it's not that bad, just my inner 11 year old showing." i think we can all agree that it is that bad.  

helpfully, a fellow astronomer suggested that "if you switched x and y, it might not be quite so snigger-worthy." i'm not sure it helped... 

and finally, yet another space vehicle for our dirty space news entertainment - Blue Origin's New Shepard space vehicle completed its first developmental test flight.

there is even a viedo of the launch!

Galaxy’s snacking habits revealed

an unexpected part of my position as "outreach officer" has been inheriting the role of "press officer" for the Australian Astronomical Observatory (AAO).  this isnt something i want to spend too much time on, but i do enjoy the occasional challenge of turning technical science results into fun stories accessible to media sources and a more general audience.

for this joint release, i received help and advice from a very experienced science communicator and press officer in western australia, pete wheeler.  much appreciated! i've learned a lot about the process of putting together the best material and advertising it properly to international media, as these are not things i've learned in my normal scientific training.

but definitely my favourite part has been the writing of the story to go with work led by AAO astronomer Ángel López-Sánchez.  so here you go - new science!

Multiwavelength image of the galaxies NGC 1512 and NGC 1510 combining optical and near-infrared data (light blue, yellow, orange), ultraviolet data (dark blue), mid-infrared data (red), and radio data (green). 

Galaxy’s snacking habits revealed

A team of Australian and Spanish astronomers have caught a greedy galaxy gobbling on its neighbours and leaving crumbs of evidence about its dietary past.

Galaxies grow by churning loose gas from their surroundings into new stars, or by swallowing neighbouring galaxies whole. However, they normally leave very few traces of their cannibalistic habits.

A study published today in Monthly Notices of the Royal Astronomical Society (MNRAS) not only reveals a spiral galaxy devouring a nearby compact dwarf galaxy, but shows evidence of its past galactic snacks in unprecedented detail.

Australian Astronomical Observatory (AAO) and Macquarie University astrophysicist, Ángel R. López-Sánchez, and his collaborators have been studying the galaxy NGC 1512 to see if its chemical story matches its physical appearance.

The team of researchers used the unique capabilities of the 3.9-metre Anglo-Australian Telescope (AAT), near Coonabarabran, New South Wales, to measure the level of chemical enrichment in the gas across the entire face of NGC 1512.

Chemical enrichment occurs when stars churn the hydrogen and helium from the Big Bang into heavier elements through nuclear reactions at their cores. These new elements are released back into space when the stars die, enriching the surrounding gas with chemicals like oxygen, which the team measured.

“We were expecting to find fresh gas or gas enriched at the same level as that of the galaxy being consumed, but were surprised to find the gases were actually the remnants of galaxies swallowed earlier,” Dr López-Sánchez said.

“The diffuse gas in the outer regions of NGC 1512 is not the pristine gas created in the Big Bang but is gas that has already been processed by previous generations of stars.”

CSIRO's Australia Telescope Compact Array, a powerful 6-km diameter radio interferometer located in eastern Australia, was used to detect large amounts of cold hydrogen gas that extends way beyond the stellar disk of the spiral galaxy NGC 1512.

"The dense pockets of hydrogen gas in the outer disk of NGC 1512 accurately pin-point regions of active star formation", said CSIRO's Dr Baerbel Koribalski, a member of the research collaboration.

When this finding was examined in combination with radio and ultraviolet observations the scientists concluded that the rich gas being processed into new stars did not come from the inner regions of the galaxy either. Instead, the gas was likely absorbed by the galaxy over its lifetime as NGC 1512 accreted other, smaller galaxies around it.

Dr Tobias Westmeier, from the International Centre for Radio Astronomy Research in Perth, said that while galaxy cannibalism has been known for many years, this is the first time that it has been observed in such fine detail.

“By using observations from both ground and space based telescopes we were able to piece together a detailed history for this galaxy and better understand how interactions and mergers with other galaxies have affected its evolution and the rate at which it formed stars,” he said.

The team’s successful and novel approach to investigating how galaxies grow is being used in a new program to further refine the best models of galaxy evolution.

For this work the astronomers used spectroscopic data from the AAT at Siding Spring Observatory in Australia to measure the chemical distribution around the galaxies. They identified the diffuse gas around the dual galaxy system using Australian Telescope Compact Array (ATCA) radio observations. In addition, they identified regions of new star formation with data from the Galaxy Evolution Explorer (GALEX) orbiting space telescope.

“The unique combination of these data provide a very powerful tool to disentangle the nature and evolution of galaxies,” said Dr López-Sánchez.

“We will observe several more galaxies using the same proven techniques to improve our understanding of the past behaviour of galaxies in the local Universe.”

A chemical enrichment map of the NGC 1512 and NGC 1510 galaxy system showing the amount of oxygen gas in the star-forming regions around the two galaxies.

Full Press Release: here.

I'm speaking around sydney

if youre in sydney and want to hear some sciencey astro goodness - i'm speaking at a few events you can attend in the next week and a half. I'll think i'll be incredibly exhausted by the end of this run, but i'm really looking forward to ALL the events.  let me know if you will be attending any!

1) The Storytelling of Science - Saturday, 16 May 2015, 2-5pm
2) Pint of Science - Tuesday, 19 May 2015, Doors Open at 6:30 for 7pm start

3) Astronomy Open Night at Macquarie Uni- Saturday, 23 May 2015, 6:30-10pm

4) The Story of Light - The Astronomer's Perspective - Sunday, 24 May 2015, 2 - 3:30 pm

details below....

astro anecdotes

there are all sorts of astronomy folklore stories passed down through generations of astronomers.

did you know that the 107'' telescope at McDonald observatory has bullet holes in the primary mirror?

Six bullet holes in the primary mirror of the 2.7m telescope at McDonald Observatory.
Photo credit: McDonald Observatory.

I used to observe with that telescope all the time during my PhD and it was always fun to walk down the solid tube to see the "damage" up close.   the six holes only block 1% of the light and were filed smooth and painted black to stop any reflected light from invading the observations!

there is a blog now dedicated to recording all these stories i keep hearing over a beer at the pub - and many more i havent yet heard in person!

you can read them all here: astro anecdotes.

How to present science to anyone

This article is originally published for Inspiring Australia in early April 2015. 


Giving a presentation is your opportunity to share your passion about a topic with an audience and empower them to wonder "why?" about the same questions that fascinate you. When the audience walks away with a deeper understanding of something you’ve convinced them is important, they will remember you and what you gave to them.

Communicating complex science ideas does not come naturally to everyone, but is a skill that can be developed with a little practice and a few basic tips. The effort is well worth the reward the first time an audience member gasps at what you say or you see a child excitedly explaining something she learned from you to her family.

The first step, before preparing any material for a presentation, activity, or interaction with the media, is to pause and think about three simple things. Make this process a part of your routine.

1. Isolate the BIG IDEA
2. Tell a story
3. Respect the audience

I will describe these three things in more detail and then give some practical suggestions to use during your presentations later in the article.

Isolate the BIG idea

What is the main thing you want your audience to walk away from your presentation understanding? This is a single statement. Say it to yourself out loud. “I want the audience to go home understanding how big the sun is.”

It is not true that adding more facts and sharing a large list of information during the brief time you have your audience’s attention is doing them a favour. Quite the opposite! As you add more facts and numbers to your presentation, the audience will start to forget the early items, their attention will drift, and they might even lose the Big Idea, which means you’ve wasted your time and theirs.

Identify the Big Idea and then 3 key points that you will use to convey your Big Idea to the audience. The rest of your interaction with them, whether it’s 5 minutes or an hour, will be bringing the audience along the journey of understanding the Big Idea and why it matters.

Tell a story

Start your science story with a hook that will instantly grab their attention. Maybe you start by asking a provocative question that might relate to their lives. You can ask them to raise their hands if they have experienced a particular thing or ever thought about how long it takes light to travel from the Sun to Earth – at the speed of light. (Eight minutes.) You can tell a quick anecdote about a person who experienced your Big Idea and how it made them feel or how it applied to their life. Try to share the human side.

Telling the story of your Big Idea will need to be presented differently for different audiences. It's not appropriate to recycle the exact same talk or activity for everyone. You should adjust presentations and activities to make them relevant to the group you are trying to reach. Have a conversation with them.

Respect the audience

This is where you consider your audience. Remember that your presentation is not about you, it’s about your audience and what you are bringing to them. Giving a presentation is your opportunity to share your fascination about a topic, leaving an audience feeling empowered by the deeper understanding of something you’ve convinced them is important.

Be mindful of the language you use: avoid jargon, get to the point, skip the details. Jargon consists of technical terms that help experts talk to each other efficiently, but is not used in everyday conversation. To a colleague you could say the sun’s diameter is 2 orders of magnitude bigger than the Earth’s. But to a general audience you would say it’s 100 times bigger. Remember, you want the audience to understand you and the words you use.

Think about what the particular audience needs to understand your story. More visuals? Interactive participation to demonstrate a concept? Talking briefly to each other about their experience? Empathise with your audience to help them get the most out of your interaction with them.

Visualise concepts and avoid using numbers

Approximate size of the Earth relative to the Sun. Image: NASA
This type of visualisation is much more memorable for the audience than a large number. Image: NASA

As a general theme, if you find yourself writing a lot of text on a slide in a presentation, especially numbers or equations, think again. Find or create a visual way you can present the concept instead.

For instance, you could write on a slide that the Sun’s diameter is 1,391,684 km. This number has no relevance to our every day experience and is therefore meaningless, other than the audience knows it’s big. You could simply say that 100 Earth’s fit across the face of the Sun. This is a better way of sharing the size because it makes it relevant to a scale the audience knows: the Earth.

Better yet, if you’re giving a visual presentation, you can show an image of the sun from a space telescope and then insert an image of the Earth next to it at its relative size. This visualisation is much more memorable for the audience than a large number. Always minimise the numbers you share and try to visualise the concept instead.

Also be mindful of the colour choices you use on your slides. Blue text on a white background is difficult to read. Small text is impossible from the back of the room (you should use at least a 20 point font, but usually bigger). And remember that some people in the audience will be colour blind.

All content should convey meaning

The content of your slide should be useful and informative for the slide’s main point. You should not read the text (there should never be that much text on a slide!). Practice so that when you look at your slide you can recall your main point. You can use notes in any presenter tool to give yourself clues, but you (and therefore your audience) should be able to identify the main point from the visual clues. Otherwise, rework your slide or practice more!

Practice your presentation
Even the most experienced presenters take time to rehearse what they will say before they say it in front of an audience.

Give yourself a confident start

• Memorize your opening and closing lines - they make the most impact. Really practice the introduction to give yourself a confident start and allow yourself to relax into the rhythm of the presentation. Your closing line will also make a strong impact. Practice your final summary statement and then afterwards thank the audience for their time and attention. This gives the audience the helpful cue that you are finished and welcomes them to applaud.

The shorter the talk, the more you need to practice

• Memorising every word of an hour-long talk is time consuming and not practical. When giving a 50-minute presentation, practice by going through each slide one-by-one and recalling the main point. 
• When giving a 10-minute talk, practice at least 5 times. When giving a 5-minute talk, practice enough times that you finish in 5 minutes every time without saying “um.”

Ask for feedback

• Practice your talk in front of friends, colleagues, or mentors and listen to the constructive criticism you receive.

Record yourself

• It is challenging and can feel embarrassing to watch yourself speak, but the practice is so useful! You might find that you need to look up at your audience more, or that you say “um” too often, or you make a clicking sound with your tongue that you didn’t realize you made. You’ll notice your posture and whether you talk too fast, or discover that you do a very strange thing with your hand while you talk! This is a tough but rewarding practice.

Stick to time

• It is disrespectful to the audience and makes you look unprepared if you go over time. The audience will become restless when you speak longer than the time allocated and they will not retain the information you rush to fit in at the end. It is important to practice your presentation so you can stay to time and leave your audience feeling inspired and respected.

Use technology wisely

• When deciding how to present to a certain group, it is not a question of “How can I use this fancy new technology?” You know your Big Idea and the three key facts you will use to tell your story. Now identify which technology will best help unfold this story. It’s finding the most appropriate tool for the job.
• You can use the technology to put cues in your talk that only you can see to remind yourself to take a breath and speak more slowly or to regain your audience’s attention when you notice it inevitably drifts.
• Human beings have attention spans of roughly 10 minutes, and probably less than 20% of the audience will be paying attention at any given moment. This means it will be helpful for you to remind the audience of your main points throughout your presentation or try a few other tricks.

• To regain the audience’s attention, change your focus every few minutes: vary the tone of your voice, use audience participation, , use the keyboard’s "B" key to provide a blank screen and bring attention back to you (try it out, it works!).

Speaking with young students

Young students are an active audience and they will be very eagre to share their stories with you! They want to show how something you’ve said relates to their life or how their mom read them something in a book once that kind of sort of relates to the topic. While being interactive with the students by asking them to raise their hands or vote throughout your presentation is useful, they will want to stop you during the presentation and ask questions, which often turn into long-winded stories once they’ve been given the attention.

An option is after you introduce yourself, tell the students that you know they’ll have a lot of interesting questions and stories to share with the group, and they will get a chance, but you have so much exciting material to get through that they should wait until the end of the presentation to ask questions.

Then at the end, start at one side of the room and hand a student an object (either ask the teacher for an object, or bring in something related to the topic). The student can ask ONE question, or not, and hand the object to the next student. This way every student gets a chance to share if they want, and you don’t accidentally call on the same student who keeps raising his hand while neglecting a potentially shy student unwilling speak up.  Only a few students will pass the object without commenting.

This works for a classroom of up to 30 students, but will take at least 20 minutes. If you have an hour with the group, talk for 30 minutes and then begin this activity. If the group is a lot bigger, it won’t work. If the students are older than about 11 years old, they usually have the attention span to handle a 45 minute presentation with a few questions at the end.

Talking to media

Always make a list of three things you want to convey to the journalist. Practice saying them out loud before the interview. Also write down a few items that you do not want to talk about if such items exist. If the journalist asks those things you can say “I prefer not to comment on that at this time.” Or “That is not relevant to the results I’m presenting today, so I won’t comment now.” Or even “That is not my area of expertise, so I won’t comment on that.” You can suggest other scientists who are experts in the area, if you want, or you just leave it and wait for another question. Or you can start talking about one of your three main points again.

Relax and enjoy

Finally, if you’re feeling particularly nervous before a presentation or interview, stand up, stretch your arms up out to the corners of the room and look up at the ceiling. Take a few deep breaths in this powerful posture. Also, a tall stance with broad shoulders will give you more confidence as you’re speaking.

Remember – have FUN! This is your opportunity to share your passion with an audience eagre to hear about it and understand why it’s important and so exciting to you.

Amanda Bauer is a Research Astronomer and Outreach Officer at the Australian Astronomical Observatory. She was named among the Top 5 Under 40 Australian researchers and science communicators in 2015 and was a Fresh Science finalist in 2013. She has been invited to give science communication talks at Gemini, dotAstronomy 5, Harley Wood Astronomy Winter School. Follow Amanda on Twitter @astropixie


Resources

Watch Amanda describe her research and why it’s relevant in 30 seconds in this Radio National video produced as part of Top 5 Under 40.




Watch this dotAstronomy 5 talk: Communication Strategies: How Do You Organise a Party in Space? You Planet.

Amanda Bauer - Communication Strategies: How do you Organize a Party in Space? - .Astronomy 5 from Robert Simpson on Vimeo.

Top 5 Under 40 in Australian Science

I'm very proud to announce that I'm a finalist for the Top 5 Under 40 in australian science! As part of the program, I'll attend a workshop this Thursday and Friday to get media production and science communication training, and then pitch an idea for a radio program to the panel of judges. eek! also, woohoo!

This initiative is supported by UNSW and ABC Radio National to mark 40 years of The Science Show. The winners - the ‘Top 5’ - will be announced on The Science Show on 7 March.  fingers crossed!

the sirens of titan

i recently finished reading Kurt Vonnegut's second novel, The Sirens of Titan.  overall, an enjoyable read. i like how vonnegut plays with words and patterns and patterns of words so nonchalantly.  it feels like an efficiently written story, deceivingly simple, yet so much happens throughout!

Saturn's largest moon, Titan (Image credit: NASA/JPL/University of Arizona) 

it seems fitting that just as i finish reading this book, NASA published a new video, Approaching Titan a Billion Times Closer, in honor of the Huygens probe touching down on Titan, ten years ago this month!

titan is saturn's largest moon and the only moon in the solar system with a dense atmosphere. the video shows a collection of images taken by the cassini spacecraft and then images from huygens, as it fell down to the surface of titan in 2005.

bouncing on a comet.

humans landed a robot on a comet last week for the first time.  yeehaw! a collaboration of scientists and engineers from 20 countries made this happen through the european space agency.

the rosetta spacecraft traveled through the solar system for 10 years, getting gravity assists from earth a few times and mars before reaching its destination: Comet 67P/Churyumov-Gerasimenko.

space craft selfie with its solar panel and comet 67P

the philae lander drifitng away from rosetta on its way to comet 67P

the philae lander spotting its landing site

unfortunately, philae did not stick the landing and drifted and bounced twice across the surface. scientists werent exactly sure where philea drifted to at first, but this morning released this compilation of images from Rosetta's camera OSIRIS. WOW! at the time, Rosetta was 15.5 km from the comet's surface. the images have a resolution of 28 cm/pixel and the enlarged insets are 17 x 17 m.

Credit: ESA

this is what philea saw upon settling still.  captions by emily lakdawalla.

philea now rests still, in hibernation.  it landed in a spot that doesnt have enough sunlight to supply energy to its working solar panel.  luckily, the little robot managed to collect all the data it was designed to collect during its short initial lifespan, AND it successfully sent all the data back to earth.
it's an exciting time for all those scientists.  i hope they got some sleep after a few days of incredible activity.  lots of science to do now.... i cant wait to hear what they find!

for your entertainment, watch the event as is played out through randall munroe's live-comic-blogging!  relive the experience here:  xkcd1446.org

light as a feather

Physicist Brian Cox visited NASA’s Space Power Facility in Cleveland, Ohio (!!!) to perform a fantastic science experiment!

did anyone ever tell you that a bowling ball and a feather would fall at equal speeds if it weren't for air resistance?  i didnt think it would be so interesting to watch the actual experiment, but they did a great job with this short clip!

steve and the stars

i'm SO EXCITED to finally get to reveal this short film "steve and the stars" to everyone. i worked with the bluebottle group to produce it for the AAO. i think it captures the excitement and wonder, that cosmic vertigo that comes when thinking about our place in this unfathomably huge universe of ours. so lucky to be able to do this as my job!



the official blurb and behind-the-scenes shots while filming in july 2014!

Ever wonder what it's like to stay up all night using a world class 4-metre telescope?

In celebration of 40 years of discovery with the AAT, the AAO has made a short film, Steve and the Stars. 

The star of the show is Head Telescope Operator, Steve Lee, who has worked at the AAT for almost its entire 40 years of operation. 

Steve guides this video tour of working with the AAT, exploring how observational techniques have changed from the 1970s to today's digital age, and the AAT’s exciting future pursuing more world-class discoveries.

The live footage was shot and edited in July 2014 by Bluebottle Films with time-lapse material by AAO's Angel Lopez-Sanchez.

just hanging with the tarantula nebula and the large magellanic cloud :)

danielle and james from bluebottle films.  great to work with them!

Never tire of sunrises on siding spring observatory

with david malin, one of the stars of the show!

most detailed simulation of our universe.

this is your universe, simulated.   watch full screen and enjoy!




"The Illustris simulation is the most ambitious computer simulation of our Universe yet performed. The calculation tracks the expansion of the universe, the gravitational pull of matter onto itself, the motion of cosmic gas, as well as the formation of stars and black holes. These physical components and processes are all modeled starting from initial conditions resembling the very young universe 300,000 years after the Big Bang and until the present day, spanning over 13.8 billion years of cosmic evolution. The simulated volume contains tens of thousands of galaxies captured in high-detail, covering a wide range of masses, rates of star formation, shapes, sizes, and with properties that agree well with the galaxy population observed in the real universe. The simulations were run on supercomputers in France, Germany, and the US. The largest was run on 8,192 compute cores, and took 19 million CPU hours. A single state-of-the-art desktop computer would require more than 2000 years to perform this calculation."

Find out more at:
http://www.illustris-project.org

Publication:
"Properties of galaxies reproduced by a hydrodynamic simulation", Vogelsberger, Genel, Springel, Torrey, Sijacki, Xu, Snyder, Bird, Nelson, Hernquist, Nature 509, 177-182 (08 May 2014) doi:10.1038/nature13316

New Zealand South Island

I recently visited new zealand's south island for a week of work.  i love that place - every turn provides a different beautiful scene.  here are some photos.

finally opened brian schmidt's 2005 maipenrai pinot noir.   it was surprisingly full bodied with a hint of cherry!  delicious :)