1 {photo of the Milky Way over a Joshua tree}
1 Caption: Night sky inspiration

Southern Cross (upper right). The bright stars at lower left are Alpha and Beta Centauri. Creative Commons Attribution-Share Alike image by Edoddridge.

Most of us live in cities, or at least large towns. There are many advantages to that: it's easier to socialise, to find work, to get an education, to be looked after if you need help, to participate in cultural activities. But in other ways it's not as good as living in a more isolated rural area. Air quality is worse, crime is more common, and it can be difficult to find simple peace and tranquility. But one difference is often overlooked. In the countryside you can see the stars.

Oh, you can see a few stars in the city, and you can see some planets with ease. But mostly, in a big city, nobody ever bothers to look up into the night sky much. Because there's simply not that much to see. You can see the brightest stars in a few familiar patterns, as they wheel about the Earth in their seasonal rotation. You may have learnt the names of some of those patterns. Here in the Southern Hemisphere where I live, the first one taught to children is the Southern Cross. It's bright and easy to pick out, and appears on the national flags of Australia, New Zealand, and several other southern countries. And if you know the simple trick you can use it to find the direction of south.^[1]

I have no personal experience, but from cultural osmosis I am fairly certain that kids in the Northern Hemisphere are instead shown how to find the Big Dipper. And in a similar fashion this provides a way to find the direction of north.^[2]

And for most people that's pretty much it. They can look up into the night sky and say, "That's a star", doing it essentially by default because almost every bright spot you see up there is a star, and they can maybe identify one pattern of stars.

Most of you reading this probably know that patterns of stars are called constellations, though I haven't used that word yet. The reason I haven't used that word is that one of the patterns I've been talking about - the Big Dipper - is not one of the recognised constellations. This group of stars is actually just a part of the larger constellation known as Ursa Major (which is Latin for Great Bear). By convention, the sky is divided into 88 named regions, deriving either from ancient Greco-Roman usage for the Northern Hemisphere, or more recent divisions for the Southern. It happens that Ursa Major is one of these constellation divisions, while the smaller Big Dipper within it is not (a conspicuous group of stars not recognised as a constellation is known as an asterism).

Orion, seen from a rural area (left) and a city (right). Creative Commons Attribution image by Jeremy Stanley.

To learn about the constellations, you either need an interested adult to teach you as a kid, or to get interested yourself and seek out the information. Even then it takes some effort to learn more about them. As a child I was certainly interested, and found books about stars and stuff, but I found it too hard to seek out the patterns of stars in my city sky and memorise them. To this day, I can only really identify three constellations in the night sky: the aforementioned Southern Cross (or Crux to give it its official Latin-based name), Orion, and Scorpius. (Yes, Scorpius. "Scorpio" is used only in astrology. In addition to its many other faults, astrology doesn't even get the names right.)

If you know about my educational background, it may surprise you to know that I can only identify three constellations. I have a doctorate in astrophysics, which one might imagine implies that I am very interested in stars. While this is true, it does not follow that I ever dedicated the requisite time to learning the constellations. I did try as a kid, but it was difficult, both because it's simply a rote memory exercise (hard work, with nothing much to really understand about it), and because I lived in a big city. Because, coming back to today's opening point, the night sky in the city is incredibly dull. It's hard to see more than the very brightest stars because of the enormous amount of light pollution that washes over the night sky and you have to make an effort to find a place not in the immediate glare of street lights.

This experience is probably repeated for most city kids, even the ones who are curious about the few stars they can see in the night sky. They just don't seem to be that big a deal. For a different perspective, you need to head out into the countryside, away from cities and towns. The amount of light a big city puts out at night is staggering. Modern astronomical observatories are situated far away from cities for a good reason.^[3] The observatory where I did the observing for my PhD was the Anglo-Australian Observatory (since renamed the Australian Astronmical Observatory) in the Warrumbungle Mountains near the town of Coonabarabran, about 450 kilometres northwest of Sydney. Coonabarabran, being the support town for the observatory, has local ordinances restricting the spill of street lighting up into the sky, but Sydney has no such thing. On the pitch black moonless nights when I did my observing, you could look to the southeast and see the glow of Sydney on the horizon, even though the city itself was well below it.

The Milky Way. Creative Commons Attribution-NonCommercial image by Joe Parks.

But the other thing you can see from such a dark place at night is stars. Lots of stars. Lots and lots of stars. The night sky glitters with pinpoints of light scattered across the velvety blackness everywhere you look.

There is also a convoluted smudgy streak of light running across the entire sky, with intricate crenellations and twists along its length. This, the Ancient Greeks supposed, was a stream of milk from the breast of the goddess Hera, spilled across the sky as she was suckling the demigod hero Heracles. That legend came down to us today in the name we give to this streak of light: the Milky Way. The word for milk in Ancient Greek was galaktos, and from this we get the other name that refers to the Milky Way: the Galaxy. With a small telescope you can see that the Milky Way is not a smear of milk, but is in fact made up of countless stars, packed so closely together that to the unaided eye they appear as a continuous smudge.

The night sky in the dark countryside is as it should be: a thing of wonder and beauty. It has inspired generations of children to wonder and to dream about the stars, and some gifted ones to go on and seek a career in studying and understanding what is in the universe around us.

Growing up in the city, I was not led to astronomy in this way. I don't really recall ever gazing up at the splendour of the night sky in a dark place as a child. Fortunately for me, there was a child before me who wondered about the stars and grew up to seek out astronomy as a career. His name was Carl Sagan, and around the time I was growing up he made a television documentary series called Cosmos. It was about the cosmos, everything. And since there is a lot more everything in space that here on Earth, much of it was about objects found in space. It was this TV series that fired my imagination and made me want to learn about stars and planets and galaxies.

Me talking to year 5 and 6 students.

My high school careers advisor was not so impressed and advised me to study medicine or engineering instead. Options that would lead to solid careers. But I defied him and studied astronomy and astrophysics at university. I got a good job anyway, because training in science is training in how to think critically, in how to organise thoughts and arguments, in how to muster information from many different sources and make sense of it all, basically in how to do many things that a responsible and professional adult needs to do in all modern technical or administrative careers. I was lucky to have Carl Sagan to inspire to me towards a job I would enjoy later in life.

Most city kids these days get no such inspiration towards astronomy. Given the impoverished night sky which offers only an unsatisfactory sampler of what is possible, combined with the modern firehose of entertainment options that seems light on documentaries capable of inspiring awe and wonder at the beauty of science, it seems amazing that any child can struggle through to first develop and then achieve a passion about the stars. I am pleased to hear that there is currently an updated remake of Cosmos in the works, to be narrated by Neil deGrasse Tyson, which I expect will be awesome. But in the meantime (and even once it's out) other things need to be done to inspire kids to think and wonder about science.

This past week I did my own little part. My job offers a few days a year for community service leave, which employees can use for volunteer and charitable work. I used one of my days to visit a primary school (kindergarten to year 6). This was coordinated by the CSIRO's Scientists in Schools program, which pairs up school teachers with working scientists to offer children exposure to science from someone actually doing it as a career.

Answering questions.

For my day at the school, I prepared a collection of slides showing the planets and moons of our solar system, as well as some spillover slides on stars. The teachers set me up in their library and I was given about 50 minutes each with a procession of classes of students of all different ages. I showed them the same slides, but adjusted my vocabulary and explanations to their comprehension levels (at least I hope I did so well enough). Many of them were keen to ask questions. It was clear a lot of them had heard about black holes and thought they were incredibly cool, but didn't really know how they worked! A couple of them in different classes also asked me about Pluto and why it wasn't a planet any more.

One very specific thing I did with my presentation was to talk briefly about and show pictures of some of the scientists who have worked in astronomy. And I deliberately loaded my selections with more women than men: Annie Cannon, who ordered the stars into a physically meaningful sequence based on their spectra, Linda Morabito, who discovered active volcanoes on Jupiter's moon Io, and Carolyn Porco, chief mission scientist for NASA's Cassini mission to Saturn. It's all too easy to subconsciously make science appear to be a male domain, and I wanted to show the young girls in my audience that they could do science too if they wanted. I didn't say it explicitly, but I made sure the message was there for them to absorb.

One scene from Cosmos that has always stayed with me was the part where Carl Sagan visited his own old primary school, and showed the kids printed photos of Jupiter and its moons from the Voyager mission and did a question and answer session with them. I always thought how cool it would be if a scientist had come to my school and done that. Now I'm the scientist and I've done it for a group of kids. They, and the teachers, liked it so much that we are already organising another visit for me later this year (I plan to talk about light). I hope that some of these children are suitably inspired to pursue an interest in science through high school, university, and into a career.

At lunch time, I walked from the library where I'd been showing planets and stars to the children, across the playground to the staff room. Several children I'd spoken to earlier in the day raced over to say hello and how much fun they'd had listening to what I had to tell them and show them. That was just the icing on the cake.

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Title image is Creative Commons Attribution-NonCommercial-Share Alike by Ross Manges.

[1] There are two ways to do this. You either extend the long axis of the cross downwards by four and a half times, thus arriving at a point which is the south celestial pole. Or you find the intersection of the long axis with the perpendicular bisector of the two very bright stars which can be found just left of the cross, which occurs at the same point.

[2] The two stars at the end of the bucket end of the dipper point to a nearby bright star, which marks the position of the north celestial pole.

[3] I'm talking about optical observatories. Although radio observatories are usually located far from cities too, and for analogous reasons: to avoid radio interference.