Scientists praise images newly sent from Hubble

Camera installed in March provides view of heavens spectacular in depth, detail

April 24, 2002|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

Just six weeks after astronauts installed a powerful new camera on the Hubble Space Telescope, its designers are raving about the quality and detail of the galactic scenery they're seeing.

"The results are just spectacular. Everyone who looks at these images is just stunned," said Johns Hopkins University astronomer Holland C. Ford, who leads the team that conceived and built the $75 million Advanced Camera for Surveys.

Speaking in his bare-walled Homewood office yesterday, Ford praised the camera's performance but declined to share any specific data or pictures.

NASA's strict publicity rules forbid the release of any images or other specifics - to the press or even the scientific community - before a Hubble news conference scheduled by NASA for next Tuesday.

The team is still working to choose initial images that will demonstrate Hubble's new power. No one seems to have been quite prepared for the depth and detail of the images they're seeing on their computer screens.

"You can spend hours looking at all you can see in these deep, panoramic images of the deep universe," Ford said. "I think the astronomical community is going to be very happy."

The instrument's promise means job security for scores of scientists and engineers directly involved in the project, and years of research grants and employment for about 800 more astronomers and graduate students around the world. Scientific observations have already begun and should be running full time by June.

Sixty percent of all Hubble research time during the next year will be spent on the Advanced Camera for Surveys. Astronomers will use it to map the large-scale structure of the universe. They expect to image galaxies and galaxy clusters in the deepest reaches of time and space, appearing as they did when they first began to form.

Scientists will use the camera's high-resolution capabilities to study black holes and other structures deep in the cores of galaxies, and to learn more about the unexplained acceleration in the expansion of the universe.

They also hope to peer into the glare of nearby stars to search for evidence of a Jupiter-like planet far enough from its star to make room for a smaller, habitable Earth-like world.

Before launch, Ford's team predicted a 10-fold improvement in Hubble's performance when the Advanced Camera for Surveys replaced the 9-year-old Wide-Field Planetary Camera 2. When others suggested they might be "hyping" their hardware, Ford's group debated whether their forecasts might be too rosy.

In the end, they decided their math - and their pre-launch simulations - were, if anything, conservative. The results they've seen so far bear that out, they say.

Ford said the Advanced Camera should surpass his pre-launch prediction that it would find as many faint galaxies in one or two years as Hubble had spotted in 12.

The Advanced Camera for Surveys (ACS) was latched into Hubble's instrument bay March 7, during the fourth Hubble servicing mission. The telescope also received new solar panels, new electrical gear and a new cooler to revive an idled infrared camera.

Since then, teams of scientists, engineers and contractors at Hopkins and the Space Telescope Science Institute in Baltimore, and at NASA's Goddard Space Flight Center in Greenbelt, have been working to adjust and calibrate the camera's components as the observatory whirls around the globe once every 90 minutes.

On March 22, the team got its first look at a star through the new camera.

"Those images were not perfect," said George Hartig, a member of the Advanced Camera team at the Space Telescope Science Institute. But the aberrations were correctable.

Engineers have since focused the camera, adjusted the tilt and alignment of its mirrors, tested its electronics and checked the movement of its filter wheels, shutters and other moving parts.

The work isn't done yet, but Hartig said, "I'm happy to say the images are all within specifications or beating specifications in some instances."

One problem that has arisen has been the sheer volume of data being generated by the instrument's jumbo light detectors, which capture a wider view of the heavens and more detail.

Each image from the new camera contains 34 million bytes of data, nearly seven times that in photographs made by the best digital cameras on the consumer market.

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