Category Archives: sloan digital sky survey

galaxies, galaxy distributions, large-scale structure, sloan digital sky survey, universe

Survey the Universe?

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How It Has Been Done with SDSS

The Perseus Cluster, as seen through the eyes of the Sloan Digital Sky Survey. Courtesy Robert Lupton. Click to biggify.

The universe is a strange and wonderful place.  How do I know this when I haven’t explored it all? When astronomers are still searching out the distant reaches and early history of the cosmos?  I know it from the work done by scientists using such observatories as the Hubble Space Telescope, the Spitzer Space Telescope, the Wilkinson Microwave Anisotropy Probe, and the phalanx of ground-based observatories such as the Subaru Telescope, the Gemini Observatory, the European Southern  Observatory, and many, many others.  Quite significantly, I know it from the results of a sky survey that revolutionized our view of the universe–mostly of the galaxies, galaxy clusters, and quasars — but also by looking at bodies in our own solar system.  That survey was the Sloan Digital Sky Survey, which has carried out deep multi-color surveys of more than a quarter of the sky. Data from its first surveys were used to create three-dimensional maps of nearly a billion galaxies and more than 120,000 quasars. It’s now in a new program of observations called SDSSIII that will continue until the year 2014.

All this work has been done using a 2.5-meter telescope on a mountain in southern New Mexico. A single telescope!  It’s an amazing and ongoing accomplishment.

The Sloan began operation in 2005, and I often wondered about the people who put it together. Certainly I’d heard plenty about the survey at meetings, and had met some of the Sloan planners. But, as with the Hubble Space Telescope, I really didn’t know much of the history of the project when I first signed on to work with an instrument team back in grad school.  HST piqued my curiosity, and so in 1992 and 1995, I worked on a book with co-author Jack Brandt (a former team lead for the Goddard High Resolution Spectrograph on HST, and now at the University of New Mexico) called Hubble Vision. I also did a planetarium/fulldome show called Hubble Vision about HST’s accomplishments, which I periodically update.

Working on those projects gave me a lot of insight into the people who make such instruments work, and their hopes and dreams for the outcome of their astronomy work.  Hubble’s history is replete with individuals who designed the instruments, solved the problems, recognized the errors of spherical aberration, and who have made the many,  many accomplishments possible.  Some of those same folks have been involved with the Sloan Digital Sky Survey, too.

I just finished reading a book about the Sloan Digital Sky Survey (SDSS, for short) and the folks who made it a reality. The book, called A Grand and Bold Thing, by Ann Finkbeiner, gives us a look not just at Sloan and its accomplishments, but at the dream it sprang from — beginning with the spiral bound notebooks of astronomer Jim Gunn (who first brought the idea up at a meeting in Tucson in 1987), and the further refinements of the first planning documents and taking us to the observations made by this project.  At one level,  the book does what Jack and I tried to do for Hubble: give readers a look at the PEOPLE behind the instruments and accomplishments.  Ann’s writing is clear and wonderful, and she really lets the reader see the history and growth of SDSS quite clearly, through the eyes of the astronomers who made it happen.  These are REAL people who sweated over the development and installation of SDSS, and their accomplishment is considerable.

Along the way, we also learn about the universe that SDSS (and all its observational siblings) has revealed to astronomers.  SDSS’s contributions to understanding the large-scale structure of the universe are considerably one of the most important achievements in astronomy.  Without the data that SDSS, and sibling surveys such as the 2DF and 6DF observations, astronomers might still literally be groping in the dark for an understanding of how matter is distributed throughout the universe.

Finkbeiner weaves in the story of thediscovery of the structure of the cosmos as she tells the story of the SDSS.  For me, entwining together the story of scientific discovery with the tale of the people who enabled the SDSS’s odyssey of discovery is a heady brew. You should drink it in for yourself!

astronomy, astronomy art, sloan digital sky survey

Art and Space

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(Left) Space Mysteries by Vance Kirkland, courtesy of the Vance Kirkland Museum Denver, Colorado
Space Mysteries by Vance Kirkland, courtesy of the Vance Kirkland Museum Denver, Colorado

I have always been interested in the many ways of depicting space objects — whether through photography, or music, or on canvas. I’m no artist, meaning that I can’t draw or paint very well, but I do know what I like to look at. And often, I can see connections between art and the cosmos. In college one year I studied art history for a summer and grew to appreciate the different ways that artists cast their subjects — on canvas, in stone, whatever direction their muse takes them.

‘Way back in the early 1980s, my husband and I were running a recording studio and getting our planetarium show business off the ground, and we happened to meet an artist named Vance Kirkland. At the time (and for more than a decade earlier) he had been exploring scenes of outer space using a method of painting that derived from pointillism — where the artist creates whole scenes by daubing small dots of paint in primary colors to build up a larger image. Mr. Kirkland was using varying sizes of wooden dowels to daub circles of paint onto huge canvases. Some of his paintings, with names like “Energy of Mysteries in Space” and “Energy of Explosions 24 Billion Years B.C.” were wall-sized (and larger) explorations of space themes in wild colors and vibrant energy. We still have hanging in our living room a poster he created to celebrate a fund-raising effort for the Denver Symphony Orchestra. And, somewhere in my library I have a series of art books illustrating the breathtaking space views that Kirkland created throughout his career.

he Cats-Paw Nebula courtesy of the 2-Micron All-Sky Survey.
The Cat's-Paw Nebula courtesy of the 2-Micron All-Sky Survey.

Vance Kirkland died in 1981, not long after we met with him and his curator, Mr. Hugh Grant. We found out later how well-known Kirkland was — his work hangs in the Denver Art Museum and a search on his name in Google turns up thousands of citations from museums and collectors around the world. Today the Vance Kirkland Museum stands in Denver as a tribute to his work and imagination.

The top image in today’s entry is a very small thumbnail of a Kirkland painting called “Space Mysteries” and as I looked at it, I realized that although it was painted in 1973, I’d recently seen a space image that looked somewhat similar to it. But where? Then I remembered. The 2-Micron All-Sky Survey — an infrared survey of the sky undertaken by a consortium of universities and observatories recently announced that its mission of archiving 5 million images of the entire sky at high resolution was complete. I’ve mined around in the 2MASS gallery over the past few months to illustrate the upcoming book Visions of the Cosmos and had run across the second image up there — the Cat’s-Paw Nebula.

NGC 6334
NGC 6334

This area of space, also called NGC 6334, is a cloud of gas and dust that appears to be the birthplace of several massive stars. It lies more than 5,000 light-years away in the constellation Scorpius. The bright sources are very young and massive stars that are radiating light so energetic and intense that it is eating away at the clouds of gas and dust that make up the nursery in which they are born. In this 2MASS image, which shows an infrared view of the scene, the warm molecular clouds of gas and dust appear as purple-blue. The stars are almost like Vance Kirkland’s points of light, scattered to form a backdrop of light against which the diaphanous clouds of the nebula float like some ethereal ghost.

Take some time to browse the 2MASS gallery (link above). The scientists who created the images have given the objects some quite imaginative names, and the images are almost like works of art themselves. The link between the very human proclivity toward art and the majesty of the universe will set your mind spinning. To quote The Moody Blues, “It’s all around if you could but perceive.”