by David Kingsley
1) From start to finish, the trip was planned around observing. That meant choosing where to go based on the lowest humidity, highest number of cloud-free skies per month, reasonable temperatures and time of the year when as many Southern showpieces would be as well placed as possible during long observing nights. It also meant forgoing many of the usual tourist activities so that we could observer all night and use daylight hours for sleeping, comparing notes, and planning the next observing session. Finally, it meant going not with families, but with friends who shared an obsessive focus on seeing as much as possible through the eyepiece during the trip. On all counts, the trip was a huge success. Fifty hours of observing under some of the most beautiful skies I have ever seen, with great companions, in one of the most interesting places I have ever visited.
2) Despite the focus on observing, the Flinders Ranges of Australia itself turned out to be an incredible scenic bonus because of its remoteness, beauty, kind people, interesting life forms, and fabulous geology. On the first night at Arkaroola, I happened to ask our host Doug Sprigg a question about fossil life forms in the area, including the rare and special Ediacaran fauna that is the first evidence of multicellular life emerging on Earth. He paused slightly and said "my dad discovered the original Ediacaran fossils here in the Flinders Ranges", and proceeded to tell us how the fossils had not been believed when first found, and how his father's Ph.D. thesis had been rejected as something that probably wasn't correct, and couldn't have all been done by one person even if it was. The information came so fast and furious that it didn't all truly sink in at the time. However that night after dinner Doug gave me a copy of a book that his father Reg Sprigg had written about the area. As I began to go through the book back in my room, all the the pieces began to fall together. Sprigg, Sprigg, SPRIGG. Oh my God, THAT SPRIGG! The SPRIGG who had made one of the most fabulous fossil discoveries of the 20th century. The same man who had recognized traces of complex, completely soft bodied animals in rocks million years older than the Cambrian period. The man who had helped solve Darwin's old dilemma of an very incomplete fossil record that started all of the sudden in the Cambrian as if a superhighway emerged from nowhere in the blowing sands of a desert (see Marek's post earlier today). Sprigg's fossils provide the key transition between the unicellular life that dominated Earth's history for billions of years, and the full blown complexity of the later Cambrian explosion. As expected, there WERE intermediate stages in this evolutionary transition. Sprigg's fossil finds at Ediacara in the Flinders Range area showed the first fossil emergence of form, pattern, multicellular complexity, heads and tails in completely soft bodied animals. Sprigg's name is now intertwined with these key evolutionary experiments, in fossils that other scientists later named to honor the importance of his early work: Spriggina floundersi" (the lowliest worm that ever lived, but the first to show a true head) "Mawsonite spriggi (a large beautiful segmented spiral).
The key discovery sites were all around us on the drives through the Flinders Ranges, and are still often in the news. In fact, the Ediacaran fossils have achieved such an importance that this weekend a dedication ceremony is being held near where we stayed in Australia the "Ediacaran period" and type specimen rocks. This is the first time a new geological period has been added to the official geological sequence in almost 120 years (See http://news.bbc.co.uk/2/hi/science/nature/3721481.stm for more information about the decision to declare a new geological period. See http://www.peripatus.gen.nz/paleontology/Ediacara.html for detailed information on Ediacaran era fossils from both South Australia and other sites)
And there we were in the middle of it all. Look down and you could see the very strata where life's complexity had first evolved on our own planet. Look up and you could contemplate the evolution of entire galaxies, stars, clusters, and nebula in the beautiful Southern skies at night.
3) The objects not visible to Northern Hemisphere observers are some of the most spectacular objects in the heavens. I have observed a lot over the last 8 years, and was stunned to repeatedly find best of class objects for almost everything in the 40 degrees of sky between -50 and -90 South.
Albert, Bob, and I discussed this one night and agreed the Northern hemisphere does win best of show in at least one narrow category.
We do have the best pole star.
4) The Magellanic clouds have to be my favorite target in the entire heavens. What an incredible feast of stunning eye candy, nebulae, and clusters. The richness leaps out of the eyepiece with science, beauty, and the complex relationships between objects. Studying the LMC in particular was like looking at the Flinders mountains around us. At first you are nearly overwhelmed by the mixture incredible beauty and bewildering complexity. With more time, you begin to see overall patterns, formations, and strata, and local neighborhoods. By the end of a week of continual observing, you begin to feel like you partly your way around, and can see how many of the different parts are related to each other.
5) For me it was impossible to look at the LMC and not think constantly about galaxies, star formation, cluster formation, and the evolution of objects in the heavens. This was particularly true because of my interest in globular clusters. I had already learned during extended galactic and extragalactic glob hunting prior to the trip that globular clusters don't have to be old. It is true that globs of the Milky Way all show highly evolved star populations, suggesting that almost all the globular clusters in our own galaxy are the products of a very early era of star formation. However, objects that look just like globs by all morphological criteria are also found in other galaxies, some of which are still remarkably young. This can be easily seen in a main sequence diagram of stars in young clusters, which are full of bright blue young stars that you would never find in the ancient globs of the Milky Way. The Magellanic clouds have these so called "blue globs" in spades, a sign of a huge burst of star formation that has occurred in recent time. What a laboratory for studying key stages in the evolution of nebula, globs, and open clusters.
6) You could also see the burst of star formation in the rows of clusters and nebulae strung along in groups in the LMC. One of my favorite fields was actually the large number of objects in the NGC 2032 and NGC 1974 region. The entire field was sprinkled with all stages of evolution from nebula to clusters. Puffs of illuminated gas that were still most nebula not yet condensed into stars (bright in OIII). Older nebula where there was lots of nebulosity but lots of stars sparkling like christmas tree lights through the haze. And several clusters right next door that looked like a pile of spilled salt against the black of space, most of the gas condensed to make the pinprick points of light shining forth in a region that nearly disappeared with an OIII filter.
7) Finally, part of the magic of this trip for me was that it was an observing adventure in the very best sense. The trip was full of objects that went way beyond long lists of "dim glow, elongated EW to NS, located near pretty field star." Lots of spectacular objects, lots of dim objects. But most importantly, lots of objects that make you think as well as see. I have a long list of things that I now want to read more about in order to understand what I observed during the trip, (both in the hills, and at the eyepiece). This is exactly the feeling that I had when I first got interested in astronomy, and is part of why a great observing session lasts much longer than the initial observations themselves.
In my day job, I am fortunate to get to work on how new life forms evolve on earth. Although I'm trained as a biologist, my interest in astronomy as a hobby comes in part from an interest in asking evolutionary questions at earlier and earlier stages. Where do planets themselves come from? Or stars, or galaxies, or the universe? Part of the reason I so enjoyed the Australia trip was getting to see so many key stages in the history of life and the universe all around me in both the skies and geology of the area. I found a passage in one of Reg Sprigg's book at Arkaroola that helps capture some of the same intersections between evolution and cosmology. This time from someone trained mostly as a geologist instead of a biologist, but from someone who had also made one of the most important discoveries about evolutionary transitions on earth during his explorations of the Flinders Ranges.
Cosmology teaches us that everything in the universe continually evolves. Nothing remains static. Dust clouds condense into galaxies or nebula. Nebulae spawn stars. Stars bud off planets. Planetary systems apparently usually separate into inner rocky worlds and outer gaseous ones. Depending on the distance from their central sun or stars, the rocky planets eventually cool enough for one or other of them to hold back some of their watery constituents from evaporation or from being radiated back into space. It is only such watery worlds, or "blue planets" such as ours, that we believe, have the potential to develop our type of living organisms. Such potential is just one other property of matter.
(Reg Sprigg- A Geologist Steps Out)
On this trip, you could see the dust clouds condensing, and the nebulae spawning stars in the beautiful eyepiece fields of Eta Carina and the LMC. And all around us in the Flinders Ranges, the jumble of own rocky world, with beautiful layered strata carrying the fossil imprint of ancient life forms, and bearing the tiny weight of a few modern life forms crawling along the present surface, admiring the view, wondering, and thinking.
What a trip. I can't wait to return.
Posted on sf-bay-tac Apr 16, 2005 05:20:21 PT
Converted by report.pm 1.2 Apr 23, 2005 20:26:03 PT