Hubble's Star Is Fading
Saturday, February 14, 2004 - Page F8 — The Globe & Mail
The most powerful eye on the universe is facing premature blindness.
The space shuttle will no longer be making maintenance trips to the Hubble telescope, as the United States space program refocuses its efforts on returning to the moon and eventually putting humans on Mars.
A shuttle service trip had been planned for 2006. It would have extended the life of the Hubble to 2010 or more. Without that mission, the telescope's stabilizing gyroscopes will cease to function and its batteries will go dead. The Hubble, which has revolutionized the study of astronomy, may be out of commission by 2007.
Astronomers and space enthusiasts are already mourning the eventual loss of one of the more important scientific instruments of all time. "There was a tremendous amount of science to be done with the Hubble and it's a shame to have to turn it off prematurely," said Patrick McCarthy, a member of the telescope's science oversight committee.
Orbiting about 605 kilometres above the Earth -- and free from the distorting effects of the atmosphere -- the telescope has provided images of unprecedented clarity of the distant cosmos.
It has peered into dusty nebulae to witness the birth of infant stars and captured ancient stars in their death throes. Hubble has also enabled scientists to estimate the age of our universe at 13.7 billion years. But even more important than the awe-inspiring pictures, data gathered by the telescope have fundamentally altered scientists' understanding of the forces that make the universe work.
Before the Hubble was sent aloft in 1990, scientists thought that they had a pretty good idea of how the universe started and where it is heading. Under the now conventional theory, the universe began with the "Big Bang" from an infinitesimally small point. The first stars were created and came together in clusters known as galaxies, which flew farther and farther apart.
Cosmologists have assumed that the universe will go in either of two directions. The force of gravity from all the matter in the universe will eventually pull the galaxies back together again in a cataclysmic "Big Crunch." Or gravity will be insufficient to reverse the outward movement and the galaxies will continue expanding at a constant rate forever.
When the Hubble was put to work to resolve the issue, it produced a completely unexpected result -- neither scenario is correct. The universe, according to telescope's measurement, is expanding outward at an accelerating rate. Even if the universe didn't end in a Big Crunch, it was supposed to keep flying apart at a steady, unchanging pace. Astronomers are at a loss to explain why the expansion is getting faster.
"It means there is some big piece of our understanding of the physics of the universe that is incomplete right now," said Michael Fall, a senior astrophysicist in Baltimore at the Space Telescope Science Institute, which runs the Hubble telescope for the National Aeronautics and Space Administration.
"No ordinary matter could . . . counteract gravity. So there is some force in nature that controls the behaviour of the universe as a whole and we didn't even know it existed until the Hubble." Physicists have dubbed the mystery force "dark energy" and are now trying to make sense of it.
Dr. Fell considers the Hubble to be NASA's greatest achievement since the Apollo moon landings. It has remained at the "cutting edge" of science because astronauts have been able to remove its old parts and replace them with updated instruments during four previous shuttle service missions.
21604 ABC News Online
The doomed Hubble space telescope has discoverd a new galaxy so faraway that its light takes 13 billion light years to reach Earth.