In the first year of my science degree, I was fortunate to land a job as an astronomy guide at the Sydney Observatory. In my role, I would lead tour groups of about 20 people. We’d look at stars and planets through telescopes.
If the skies were filled from horizon to horizon with clouds, we’d explore more of the universe through a 3D theatre. And to peer beyond what our telescopes could see, we’d pile inside the cosy planetarium, seeing what the light pollution of Sydney and clouds would often obstruct from our view. My favourite object to show in the planetarium was the Hubble Ultra Deep Field image.
Before revealing the image, I’d explain how the Hubble space telescope had stared at a piece of sky the size of a grain of sand held at arm’s length for 11 days, collecting enough light to look into the farthest corners of the universe. Then I’d zoom in on that tiny piece of sky, revealing the gorgeous image. At least one person would audibly gasp at the reveal.
I’d get them to spot the spiky objects in the image. There were four obvious stars that were part of our galaxy, the Milky Way. I’d seal the existential crisis by saying: “Those spiky objects are stars.
Everything else you see in this image, every blob, every smudge, every tiny speck … is a galaxy.” Cue the shock and awe. On one tour, the clouds were not working with us. So, after showing the group the “stars” through the telescope – the stars on the Australian flag hoisted atop the Sydney Harbour Bridge – I led us down to the 3D theatre.
Eventually, the imagination and curiosity of the group took us to the topic of black holes. Everyone loves black holes. You can talk about the first black hole to be discovered, how they got their name, and – one of my favourite topics – spaghettification.
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