BALTIMORE, OCT. 4 -- For a jittery, nearsighted robot, the Hubble Space Telescope has produced what one scientist called some "shockingly good pictures," including a dazzling new image of Saturn and what may be the play of light bounced from the walls of a black hole.

But the telescope's latest art work is a mix of agony as well as ecstasy for scientists. It not only demonstrates that the orbiting observatory can perform better than they first feared, despite a flaw in its main mirror; it also reveals the Hubble's limits and reminds scientists of what might have been.

"I'm cheerfully depressed," said Ricardo Giacconi, who heads NASA's Space Telescope Science Institute here, where the new images were released at a workshop today.

The telescope, launched into orbit 380 miles above Earth in April, still captures relatively bright objects in much more detail than ground-based telescopes can do and, with computer enhancement, promises great new discoveries once it is fully operational, Giacconi said.

But the built-in flaw, revealed in late June, has cost the Hubble its ability to discern details in very faint, distant objects, scientists said.

The new images "illustrate the glory and the tragedy of the space telescope all in one go," said Sandra Faber of the Lick Observatory.

One of its primary missions was to discover the rate at which the universe is expanding, and therefore its age. But the new images indicate that the unusual stars that were to be used as yardsticks for this purpose are too faint for the Hubble, at least until a crew of shuttle astronauts gives the telescope what amounts to a new pair of glasses in 1993.

Meanwhile, the Hubble has illuminated some new paths for scientists to follow.

For example, the Wide Field and Planetary Camera has revealed for the first time small clouds of ionized gas at the very core of a nearby spiral galaxy, glowing "like moths caught in a flashlight beam," said Holland Ford of Johns Hopkins University.

The source of the light, he said, is believed to be the energy at the edge of a black hole -- an object with one million times the mass of the sun compressed to a single small point.

The team used the European-built Faint Object Camera to follow up on a ground-based search for a faint double star lost amid 100,000 others in what is known as globular cluster M14, 70,000 light-years from earth.

The star had stood out in images taken in 1938, when it suddenly erupted cataclysmically, becoming 10 times as bright as normal for a brief period. This phase of stellar evolution is known as a nova -- an event not quite as powerful as the devastating star explosion known as a supernova.

Scientists wanted to catch such a star in its diminished, or quiescent, state, so they trained the Hubble on that area.

In the Hubble images, hundreds of separate stars leap into view in a tiny piece of sky where only dozens of blurred stars show up in pictures taken on the ground.

At the point where astronomers had hoped to find the nova star in its quiet state, they found six different candidates. The Hubble's sharp detailing also revealed that a "peculiar color" previously thought to be a signature of the nova was not present in any of them.

"Nature has decided to be particularly devious in this case," said Bruce Margon of the University of Washington. The peculiar color turned out to be the result of the sum of the six images. In other words, scientists have been fooled for years.

This means there will be "extreme chaos in the study of peculiar objects with funny color," he said gleefully. "That will be fun!"

The "bad news," he added, "is that we're still not sure which of about 15 or 20 objects is the nova."

Further analysis may reveal it. "This is clearly a project that would be hopeless from the ground," Margon said.

The Hubble's view of Saturn, comparable to some of the Voyager spacecraft's long-distance shots as it passed the planet from a different angle, shows a break in Saturn's rings that has never been captured in ground-based photographs, although it has been seen by observers.

The image of Saturn "demonstrates the superb image detail the telescope is potentially capable of. . . using computer processing to compensate for the defect," said William Baum of the University of Washington.

But he added, "It can only be done effectively for bright objects. Therefore it is urgent that we fix the telescope so that faint distant objects in the universe can be explored in the same exquisite detail."