The starlings have been evicted, and the Maryland Science Center's long-neglected rooftop observatory in Baltimore is once again providing dramatic views of whatever stars and planets manage to shine through the city's nighttime glare.
"It's working like crazy. It's really great," said Jim O'Leary, director of the Davis Planetarium.
A $100,000, year-long restoration of the observatory climaxed last week with the re-mounting of the science center's refurbished and updated 1927 Alvan Clark & Sons refracting telescope. Excited staffers have followed that with a series of pre-dawn tests of the system's 71-year-old optics and modern electronics.
"We had an absolutely beautiful image of the planet Jupiter, with all the banded stripes and some cloud details," O'Leary said. "We also looked at the moon, which is visible as a nice crescent at sunset. There were great craters rising out of the darkness, and mountains half in shadow and half in brightness. The moon's a very familiar thing in the sky, but through the telescope, it makes me go, 'Wow!' "
Further tests and staff training should be finished by Aug. 26, officials say. By September, science center visitors should be getting a good look at the sun, moon, galaxies, bright stars and planets.
City smog and bright lights blot out most of the night sky. "If you were a professional astronomer doing Ph.D research, you would be out of your mind" to mount a telescope in Baltimore, O'Leary said.
"But we're not doing any research here," he said. "We're looking at things that are visible all the time. And here, we've got the location, the crowds are coming and we need to take advantage of it."
Those who can't climb the 25 steps to the dome, and groups that can't fit onto its 20-foot-diameter observing floor, will be able to watch via live TV links to the planetarium downstairs.
The 8-inch diameter telescope was purchased by the Maryland Academy of Sciences in 1927 for $1,500. For many years it was a popular attraction for Baltimoreans who climbed to the roof of the Enoch Pratt Free Library's main branch.
But in the 1950s, its 10-foot tube, glass lenses, brass fittings and knobs were put into storage. Joe Halley ("like the comet"), chief technician for the planetarium, first encountered the telescope in a storefront storage room on Howard Street.
"It was actually laying on the floor in a million pieces. It had been taken apart by a Boy Scout troop," he said. He restored it, and in 1980 installed it in the observatory of the Inner Harbor's then-new Maryland Science Center.
Visitors and staff alike used to troop up to the dome for a look at the sky and other attractions. "We used to watch the peregrine falcons on the USF&G; building," Halley said, "and I first saw Mars through this telescope."
But access to the dome was limited and, as a consequence, it fell into disuse. Rust and nesting materials left by generations of starlings jammed the rollers vital to the movement of both the dome and its hand-cranked sliding doors. By 1990, the dome was inoperable.
The observatory needed an angel. Last year it found two in Monica and Richard Coleman, natural history enthusiasts from Pasadena who donated the $100,000 for its restoration.
At first, science center officials debated whether to salvage or replace the old Alvan Clark telescope. After all, many amateurs today have more powerful instruments in their back yards.
But the telescope was "the sentimental favorite," Halley said.
It is powerful enough for the bright objects visible from downtown Baltimore. And best of all, it looks the way people expect it to look -- a long tube with lots of brass.
Alvan Clark and his son, Alvan Graham Clark, of Cambridge, Mass., were among the nation's premier telescope manufacturers in the 19th and early 20th centuries. Their instruments remain in use at many observatories around the country.
All are refractors, meaning they use glass lenses rather than mirrors to collect and focus the light from stars and planets. And Clarks came in all sizes.
"They made the two largest telescopes of this type," O'Leary said. The biggest -- a 40-inch diameter refractor -- is still used at the University of Chicago's Yerkes Observatory in Wisconsin.
The diameter of the glass lens determines how much light can enter the telescope, and how much detail can be seen. Its magnifying power depends on which eyepiece lens its operators choose to install.
The science center's telescope has an 8-inch lens at the far end of its 10-foot tube. A selection of new eyepieces has been acquired for the near end.
Most of the time, O'Leary said, the telescope will be operated at low to medium magnification. That's plenty for the sun, the moon, planets and any comets that cross Baltimore's sky.
Restoring the observatory required both functional and cosmetic repairs.
On the roof, the dome was cleaned and lubricated; the observing room was carpeted, furnished and wired for modern electronics.
In the planetarium workshop, the telescope was rebuilt. Brass knobs, nuts, bolts and washers were cleaned and sent out to be polished and lacquered. The telescope's vital objective lens -- made of two precisely shaped pieces of glass sandwiched together -- showed some signs of age, but not enough to affect its performance. So it was left untouched.
"The two elements were ground and aligned to work together, and we don't want to get them out of alignment," O'Leary said.
Live video images
Less critical was the telescope's black metal tube of rolled sheet steel. It was repainted red "for marketing purposes," Halley said. It's a little like painting Ford's Model-T red, and the idea divided the staff. But red prevailed. What's newest and most exciting about the old telescope will be its many technological updates.
"We're still going to be able to point and shoot," O'Leary said. "We want people to experience what it's like to look through a telescope."
But to serve those who can't climb the 25 steps to the dome, and groups that won't fit, the science center will transmit live video images from the telescope to the planetarium theater two floors below. Images recorded on clear days and nights will be replayed for visitors who arrive on cloudy days.
Off-the-shelf software and computerized controls enable planetarium staff to move the telescope from one target to the next by remote control.
"We never have to touch this telescope to find something in the sky," O'Leary said. "We can say, 'Let's go find the bright star Arcturus,' and magically it goes there." You name it, and we can find it."
A selection of filters will help to screen out as much nighttime light pollution as possible, or to filter the sun's light in daytime to safely reveal its hidden features.
The reopened observatory will likely give many visitors their first intimate glimpses of the moon's craters, spots and flares on the sun, and Saturn's rings.
"And it's that first personal connection with the sky that makes it so special," O'Leary said. "We hope it will get kids and adults excited enough that they will go out and do it themselves."
Pub Date: 6/30/98