Professor Penny Sackett was six months into her five-year term as director of the ANU’s Research School of Astronomy and Astrophysics when a conflagration – small by the standards of her science – hit planet Earth.
The January 18 fires raced through the research school’s Mount Stromlo Observatory, destroying buildings, telescopes and research work. The monetary damage alone was $40 million. The school also runs the Siding Spring Observatory near Coonabarabran.
Sackett, originally from the United States, in a new job in a new country found she had to look at the recovery.
“I did remark to the Vice-Chancellor that this was not in the job description,” she said.
But much of the directing of the recovery has now been taken over by others and she can concentrate on astronomy.
One of her main tasks is the setting up of a planetary science institute at ANU.
Planets have been back in vogue in the past decade with the discovery of planets outside our solar system – first confirmed in 1995. Now more than 100 have been discovered.
“This opened up a field in astronomy which in many ways lay dormant,” Sackett says. “Our own solar system provides us with very detailed information. But if the only thing you study is your own system you can be led astray. It could be abnormal and we would never know.
“In fact, we now know that some planetary systems are nothing like ours, making this a very rich and exciting field of study. One question we need to answer is: Why is our solar system so different from so many others?
“The institute of planetary science is just in its infancy. We have obtained some seed money from the ANU. The Research School of Astronomy and Astrophysics and the Research School of Earth Sciences are combining forces and the planetary institute will fit somewhere in between.
“Much of detailed knowledge of our solar system has most recently been gathered by earth scientists, rather than astronomers. So now we need to bring these two bodies of knowledge back together. We are very excited about the possibilities, because Australia is known for its excellent astronomers and its excellent geologists.”
Back on the ground, Sackett’s school has been salvaging more than initially expected from the fires. The school was engaged in the construction of two critical instruments for the Gemini twin eight-metre telescope project – one telescope in the north (Hawaii) and one in the south (Chile). Australia has a 6 per cent share in the consortium which comprises the US, Britain, Canada, Chile, Australia, Argentina and Brazil. The two telescopes will work with visible light and infrared to obtain exquisitely sharp pictures.
The first instrument, the $5 million Near-infrared Integral Field Spectrograph (NIFS) for Gemini North was almost completed when it was destroyed by the fire. And just before the fire, Mount Stromlo had signed a contract to build a $6.3 million special camera for the Gemini South Telescope. It looked as if that second contract could be lost and any chance of Stromlo rebuilding NIFS was bleak.
“But shortly after the fire, people from Gemini came out and saw we had already placed our people in workshops down on campus and also at the Australian Defence Force Academy,” Sackett said. “They could see we had found a way to continue. The design work just needs people and computers and so was not affected by the fire.
“As for NIFS, we are taking the primary responsibility for it and we have just signed a contract with Auspace here in Canberra. They will sub-contract most of the work up to the stage where the instrument was at the time of the fire when we will take it back for the final testing.”
It should be finished by the end 2004.
“In the short term the fire was very devastating,” she said. “People who had worked on Stromlo for decades saw buildings, instruments and telescopes destroyed – telescopes which they had worked on for years and knew inside-out with all their idiosyncrasies. But people quickly came to realise that what makes this place special in a large part is the people themselves. And the historical context of this place is very special. And then of course there is its international reputation. So with those elements, we set about to rebuild. People here were determined to come back to the mountain and to make Stromlo better than the Stromlo which had been destroyed.
“The fire has brought the future closer to us. Just before the fire we were involved in a strategic planning process asking the question: Where would we like to be in five years’ time? The fire has brought that forward. We need to be there now. So the disaster is actually an opportunity because it allows us to start with a clean – well, not quite clean – slate.”
As for growing Canberra suburban night light she says the school has been moving its telescopes to Siding Spring for quite some time. Dark-sky astronomy would now completely move to Siding Spring. Stromlo would do high-resolution spectroscopy. This is where you look at objects that are much brighter than the background sky, breaking the light from a single bright star into its components across a spectrum to give you information about how this star is moving and what it is made of.
As for new telescopes, that is a matter of finance. The Commonwealth gave $7.3 million in its last budget, but that is much smaller than the loss. Insurance has not yet been worked out.
Ideally, there would be one new dark-sky telescope at Siding Spring (which would be used to digitally map the entire southern sky) and one new telescope at Stromlo to do the spectroscopy, to provide public access, and to be an educational telescope for the students at ANU.
“This is a unique position,” Sackett says. “School children come to the nation’s capital and while they are here they can also come to Stromlo and learn about astronomy and some Australian history that this place represents as well. . . .
“I love Canberra. I was surprised to learn that so many Australians had a jaded attitude toward it. Canberra is large enough to have its own cultural activities and small enough to get anywhere you like very quickly. The community is small enough so that you meet people again. And it is two hours to the mountains and two hours to the beach. . . . I grew up in Nebraska, where there are wide open spaces, so in that regard I’m quite comfortable in Australia.”
As for her work, she says, “I am interested in extra-solar planets, dark matter in galaxies, and the structure of galaxies.
“At least 90 per cent of the universe is made up of something or influenced by something that we do not understand. Which is a bit embarrassing. . . .
“I have been involved in searching for planets using a technique called micro-lensing. The Great Melbourne telescope at Stromlo for many years did an experiment called the MACHO experiment – – MAssive Compact Halo Objects. The idea was that if this dark matter was in lumps that were large enough and massive enough to bend light through their own gravitational field this would cause flickering of the stars because as this dark object moved in front of the background star it would refocus the light through your telescope and make it brighter. After the star moved on its way out of the dark object’s influence,
it would return to its usual brightness.
“This was predicted by Einstein in 1936 and was observed for the first time on this mountain in 1992. It has become a whole field in and of itself in astronomy.
“Usually the rise and fall of the brightness is very smooth, but if you are dealing with a lensing star with planets, those planets will have their own gravitational field and the light will be bent in a different way. That will alter of the shape of the rise and fall of the brightness of the background star. Instead of being a smooth rise and fall, there will be a sharp little kink which would be a signature of a planet. . . .
“I have been involved for many years in something called the PLANET collaboration which has telescopes in Tasmania, Perth, South America and southern Africa. Basically we continually watch s
tars that are undergoing this microlensing effect to see if there is any oddity that might be caused by a planet.”
Sackett explained that another way to search for an extra-solar planet was to look for the effect of a partial eclipse of its mother star. During such a partial eclipse, some of the light coming to Earth would be blocked. The percentage of the light blocked helps an astronomer work out the planet’s size. Astronomers have also taken a spectrum of the light before, during and after a partial eclipse. The difference in the spectra reveals a difference in chemical composition. For example, it was found that one planet had sodium in its atmosphere.
“The evidence coming in indicates that these solar systems are different from ours,” Sackett says. For example, one has a planet the size of Jupiter orbiting its star once every 4.5 days at a distance much much closer than Mercury orbits our Sun.”
Sackett says that curiosity drives her.
“By studying cosmic questions like this you view your own life, planet Earth, and the people on it from a different perspective,” she says. “It is not why I do it, but it is a result, I think, of studying astronomy. You take the big view.”
Does astronomy enforce or negate religion?
“It might for some people but it does not for me,” she says. “It is orthogonal. I do not see it as either enforcing or negating it. Some scientists are religious and some scientists are not. . . . I certainly think that there is a lot out there that we do not understand, and to be a good scientist you have to realise that. I do believe, though, that there is a larger arena that we can understand through science, and I think that humans are somehow endowed with this intense curiosity, so that if there is something out there that we can know, we want to know it — whether it affects our lives or not. There have been many, many examples of scientific discoveries that you would not have thought would affect human lives but they turn out to do so later. Whether this enormous curiosity is unique to humans I do not know. Whether there are other creatures in the universe who are just as curious as we are, I don’t know.
“Science is a hunt for answers. In that regard at least science has something in common with religion, which I think is also a desire to find answers. But the kind of questions they can answer are very different. Confusion comes when they try to answer the same question.”