Wednesday, September 06, 2006
This recently released update of a previous Hubble image is the remnant of a supernova -- a star that blew itself apart -- in the constellation Cassiopeia. (Click to enlarge, please!) It is known as Cassiopeia A and just happens to be the brightest radio source in the sky outside of the solar system. The progenitor event was the most recent supernova explosion in our part of the Milky Way Galaxy. It occurred in about the year 1667, although apparently it was not observed on Earth, possibly for reasons you can read about here. (Curiously, another supernova in the same part of the sky and at about the same distance away was famously observed a century earlier by Tycho Brahe, the great Danish astronomer.)
What we are looking at is a bubble, not a ring; it is the thick sides of the bubble that show up best in the photograph. Here is a dying star spewing into space oxygen, nitrogen, silicon, iron, the stuff of butterflies and brooks. The material is still racing outward to a possible destiny as the building blocks of future planets.
A dozen years ago I wrote in the Boston Globe that the Hubble Space Telescope was "too big, too expensive and too late."
I still wonder if astronomy might have been better served if those billions had been spent on innovative ground-based technologies: segmented mirrors, light detectors, digital stabilization, image enhancement, and so on. Nor am I sure that the sum total of Hubble science has been worth the price.
Still, I'd hate to forego the pics. They may be the most expensive photographs ever made, but they touch the soul as deeply as they inform the intellect. What the great Gothic cathedrals were to the Middle Ages, the Hubble Space Telescope is to our own time: an extravagant assertion of our abiding faith that there is more to this universe than life on Earth. Abbot Suger of Saint-Denis, one of the first great Gothic builders, hoped that his cathedral would reveal the divine harmony that reconciles all discord, and that it would inspire in those who beheld it a desire to establish that same harmony within the moral order. If the Hubble images could do the same they would be worth every penny.