...according to Kirsten Banks, 21
Our galaxy is on a collision course with the Andromeda galaxy
“Our galaxy is going to collide with our nearest neighbour, but it won’t happen for another 3 billion years. We’re attracted toward each other because of gravity. You know in a movie when two friends do a slow motion run toward each other? That’s us and Andromeda. We’ll give a big hug, and eventually rip each other apart. But by that time the sun will have swelled up to a red giant and we’ll have all burned.”
Aboriginal Australians were our first astronomers
“Indigenous Australians were the first people on our continent to look up and take meaning from the night sky, and while a lot of it is spiritual, there is science in it as well. I just released a research paper on the role of planets in Aboriginal astronomy, and the Wardaman people talk about the planets being spirits that walk the path in the sky both forward and backwards, and when I read that story a few times over I realise ‘backwards moving planets? Ah, retrograde motion’, which is a modern scientific concept. It’s really cool that they were able to take meaning from the stars and the planets without telescopes or technology.”
Nullarbor Roadhouse is the best place to look at the stars
“My family and I did the longest golf course in the Southern Hemisphere, the Nullarbor Golf Course, which goes from Ceduna in South Australia to Kalgoorlie. This place has a pub, a service station, a motel, a caravan park, one street light – and that’s it. The night we were there the main generator backed out, so all the lights turned off, and I cried. It was that incredible. We saw thousands of stars and this milkiness in the sky. I could even see some deep-sky objects like the Orion Nebula and the Pleiades.”
The Emu in the Sky is like a seasonal menu in the heavens
“You use the dark parts of the Milky Way to manifest this huge image of an emu that stretches over more than half of the night sky. In my country, Wiradjuri country, we use it as a tool to let us know when to find emu eggs. When it’s in the eastern side of the sky after the sun goes down, it kind of looks like it’s running along the horizon, which tells us that the emus are now running around trying to make a nest. Later in the year the body comes up to the top of the sky it looks like an egg in a nest, which tells us that now’s the right time to go looking for emu eggs.”
The universe makes gold
“All the gold on people’s wedding rings was formed in a neutron star collision. Last year astronomers and scientists released media about two neutron stars colliding, and in this particular collision about ten Earth masses of gold was created. That’s gold to the size of ten of our planets! If you were to value that amount of gold it would cost about 100 octillion dollars – that’s a one with 29 zeros. Imagine that in $2 coins and you’d get a stack long enough to stretch from Earth to the point where these two stars collided, and back again, 5,000 times.”
You should always look up
“Earlier this week I saw two meteors fall out of the sky. I was walking by moonlight with my friends near Port Botany and we saw a space rock fall through our atmosphere, a falling star. Physics for me is understanding that magic of the universe.”
Kirsten Banks is a tour guide at Sydney Observatory. She is speaking at this year's Sydney Science Festival.
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