Southern Skies, Smiling at Me

By Phil Plait

SLATE

Posted Sunday, Sept. 1, 2013, at 8:00 AM

I was in Australia recently as part of a series of events that have left me feeling pretty happy. I gave a taste of all that in an earlier post, but one night in particular affected me deeply, and I want to share it.

I gave a talk at the Sydney Observatory to a full house of roughly 200 people (my thanks to Toner Stephenson for her great job organizing it!). It was my “Death from the Skies!” talk, where I have a lot of fun talking about asteroid impacts and what we can do to prevent them. Despite the title, I end the talk on an up note, saying that we can in fact save the world, and it’s my favorite lecture to give.

A lot of friends I rarely get to see were in the audience, including Richard Saunders and Jo Benhamu from the Australian Skeptics, and Amanda Bauer, an astronomer with the Australian Astronomical Observatory. Amanda is one of those friends you can have where you’ve known each other so long that the first time you met is shrouded in a fog; neither of us can quite remember where we first got together.

After my talk we got a nice tour of the observatory, including a chance to go up on the roof, which is not usually open to visitors because it’s not a big area. But the view! Amanda posted a picture of what we saw of the Sydney Harbor, and it was mesmerizing.

While we were up there, she suddenly laughed and said, “Phil, don’t move!” She squatted down in front of me, and I looked at her while she took my picture; I held as still as I could. I wasn’t sure why she took that shot until I saw the picture later:

Do I look a bit Cross?
Photo by Amanda Bauer, used by permission

[Full disclosure: I fiddled a bit with the color balance and exposure to make it clearer but otherwise this is untouched. I wish I had smiled though.] That’s me, looming over her, but in the sky are sights invisible to most of us hailing from the northern hemisphere: The bright star is Alpha Centauri, the closest star system to the Sun, and just below and to the right is Beta Cen. Below them is the famed Southern Cross, easily visible even though we were essentially in downtown Sydney. They were sparking and crystal clear that night. Entrancing. Our Earth permanently blocks this view for those of us far enough north of the Equator, making this sight that much more special.

We also went into the dome to look at a few astronomical objects through the observatory’s lovely 40 cm. Meade telescope. While others looked through the eyepiece, I took a moment to peer through the slit of the dome. Amanda caught this too, unbeknownst to me.

Astronomers do, in fact, look up at the sky.
Photo by Amanda Bauer, used be permission

You can see the Moon and Venus, and the bright star Spica. Even this relatively simple picture is amazing to me: The horns of the crescent Moon are pointing the wrong way. It’s a bit overexposed, but if you look closely you can see that they point up and to the right. In the northern hemisphere, the setting crescent new Moon has the crescent horns pointing up and to the left! But in the southern hemisphere your head is upside-down, in a sense, and so on the sky left and right are reversed. It’s disconcerting; at one point during my visit I was sitting at my terminal in the airport as the Sun rose, and I was thinking in a few minutes it would move behind a column to the right and be blocked.

Minutes later it was still in my eyes, and I realized my northern hemisphere bias got me again: The Sun was moving to the left, not the right. I got up and moved to another seat, smiling to myself.

But still, there’s more. Through the telescope we observed the wonders of Saturn, the globular cluster Omega Centauri, a multicolored star cluster called the Jewel Box, and the extremely red star DY Crucis. These were all picked by the telescope operator, but when the Observatory Senior Educator Geoff Wyatt asked me if there were anything in particular I’d like to see, I didn’t have a hard choice: Eta Carinae, I told him.

Eta Car is a massive star, nearly 100 times the heft of our own Sun. At that size, it is just barely stable: The vast energy boiling up from within the star is so furious it can barely hold itself together. In the 1800s it underwent a spasm so mind-bogglingly huge it nearly exploded, and the energy released was second only to a supernova itself. The star erupted, blasting out two oppositely directed bubbles of matter that each are as massive as the Sun!

Hubble's view of the doomed star Eta Carinae, which violently blasted out huge bubbles of gas in the 1800s.
Photo by NASA and J. Morse (University of Colorado)

When I looked through the eyepiece, I was stunned. Expanding as they have been at high speed for two centuries, the hourglass-shaped lobes were easily visible by eye in the telescope, two tiny but perfect red circles. I stood there, shocked. When I worked on Hubble Space Telescope, I was involved with an ongoing project observing Eta Car. The observations came in every few months, and were extremely difficult to analyze; the expanding gas in the lobes were a huge mess. The spectra were fiercely complex to begin with, but all that gas moving around made them far worse. It was like a forensic scientist trying to analyze a piece of glass that had a hundred thumbprints on it from different people, and trying to figure out which feature belonged to whom.

So I was familiar with Eta Car, and could even tell you quite a bit about the science going on in that spectacular event. But all of that fell away as I stood there, letting light from that distant object fall into my eyes. It was perfect; a gem floating in space. I actually had a moment of dizziness, an almost disorienting sensation as the knowledge I had of the object battled it out with the reality of what I was seeing. And then it all came together, and for a few seconds I had a glorious feeling of cohesion, a nearly zen-like state of comprehending different aspects of the same object, all of them coming together to shape my view and grasp of it.

I’ve only experienced this once before in my life, and it was again in Australia, when I saw the Large Magellanic Cloud for the first time. The story behind that is very similar, too.

Richard Saunders, who hosts the podcast Skeptic Zone, was there with his recorder, and we talked about Eta Car (as well as the wonder of the southern skies) as I looked at it through the telescope. He put it all up on the Skeptic Zone site. You can also hear from Amanda Bauer and Jo Benhamu as well.

I love astronomical pictures, both as a scientist and as a human with a sense of the beauty of the Universe. But there is nothing, nothing, like standing at the eyepiece of a telescope and having the photons from some distant object enter your eyes and tickle your retinae. Those photons have traveled for billions, trillions, quadrillions of kilometers, and end their journey at you. No one else will ever see those exact same bundles of light, because those specific photons have been converted into electric signals in your brain, allowing you to appreciate and perhaps even understand their source.

Astronomy is such a fantastic field of study. It combines art and science, beauty and reality, seeing and knowing. Telescopes are magical: They convert light into wonder.