Few professional astronomers use a telescope to explore the heavens. Geoff Watts asks whether computers have killed off a golden age

You, the telescope, the night sky and a myriad stars at which to gaze in delight. Romantic stuff, this astronomy business. Or so it was in the 19th century.

"We see a world that is, to my mind, by far the most wonderful," rhapsodises astronomer Swithin St Cleeve as he and his companion, the black-haired beauty Lady Constantine, peer through the eyepiece of his telescope in Thomas Hardy's 1882 novel Two on a Tower .

"We will get outside the solar system altogether, leave the whole group of sun, primary and secondary planets quite behind us in our flight, as a bird might leave its bush and sweep into the whole forest," the astronomer says as the couple begin an illicit liaison. As Hardy himself explains, telling a love story in the context of astronomy was "the outcome of a wish to set the emotional history of two infinitesimal lives against the stupendous background of the stellar universe".

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Whether Hardy would find the conditions under which 21st-century astronomers work as promising a setting is difficult to say. The modern St Cleeve would sit in a noisy, brightly lit operations room staring at a computer terminal. Or he might even be looking at the screen of his office PC, a global hemisphere away from the telescope. In short the romance has vanished from astronomy.

This is certainly the opinion of Roger Griffin, emeritus professor of observational astronomy at the Institute of Astronomy in Cambridge. His love affair with the sky began in childhood, and remains an essential part of his life. He has worked with the huge 200-inch instrument on Mount Palomar and now uses a more modest telescope in Cambridge. But it's still astronomy in the old-fashioned sense. "I actually sit in a cold dome that's open to the sky," he explains. "I find stars by looking through an optical eyepiece."

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This makes Griffin something of a rarity. "Other people think I'm a dinosaur," he admits.

"`Astronomy is now just like any other form of physics. Even if people do go to the observatory, they're not looking through telescopes. They're sitting in a room surrounded by banks of television screens. They don't know anything about the sky."

Changes such as this have come about not because astronomers have mysteriously lost their souls, but through developments in technology.

"Prior to about 1880, if you wanted a picture of something you had to put your eye to a telescope, get a pencil and paper, and then draw it," says David Hughes, professor of astronomy at Sheffield University. "When photography came in, the observer started to become divorced from the image; all the astronomer was doing was pointing the telescope in the right direction."

Telescopes have become vast pieces of engineering. Michael Rowan-Robinson, professor of astrophysics at Imperial College London, compares the largest of them to battleships. Maintaining and operating them has become a job in itself. But traditionally, he adds, the astronomer was there in the control room, telling the operator where to point the instrument. "You directed the whole run. You'd prepared your list of sources and your plan. You had to check the weather and decide if it was worth going ahead."

The need to look through the telescope finally vanished some 30 years ago when everything went digital, points out Simon Mitton, astronomer and fellow of St Edmund's College, Cambridge. "Computers began to control telescopes. One of the drivers was the need to position instruments that were located not on the ground but in space. All the procedures you need for observing remotely, without having to go to an observatory, had to be established," he says.

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And such procedures were applicable to ground instruments. When detector technology moved away from photography in favour of digital recordings from electronic photodetectors, the astronomer had even less reason to be present at the telescope.

Rowan-Robinson recalls some recent observing time he booked on a German instrument. "I didn't go to the telescope at all," he says. "I just got a lot of data files and a lot of e-mails. It wasn't very exciting. But of course it was much quicker."

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So what, exactly, has been lost? "The modern observational astronomer no longer has the thrill of walking in the cool night air and seeing the grandeur of the cosmos," Mitton says. "The sight of the night sky from an observatory is wonderful. You may be able to see up to 2,000 stars, and they look close enough to touch. You don't get that if you're working in a lab."

This sense of loss is shared by Rowan-Robinson: "Observing has always been a lot of fun. You go to these amazing mountain tops, and it's usually been an expedition to get there. When you have a break from observing, you can go out on the mountain and see the sky. If you spend all your day peering at computer terminals, it's hard to find the meaning in it."

Sir Martin Rees, the Astronomer Royal, has never been one of the observing fraternity; he has spent his life sifting through the data produced by others, interpreting them and using them to synthesise or test new ideas about what is happening in the distant universe. But does he get a buzz out of looking through a telescope at the stars? "I do, yes, in an amateurish way," he says. "But even without a telescope, what I know about astronomy increases my appreciation of the night sky." He concedes that "a certain immediacy in communing with nature" has been lost but he adds that it's no more the case in astronomy than in any science that has progressed from field working to lab-based experiments.

As Sir Martin points out, the flood of data has fuelled an equal outpouring of insights into the cosmos and proved an immeasurable stimulus to human imagination, generating ideas as powerful as the Big Bang, recording images as captivating as the death of a star and teasing our minds with concepts as difficult as a black hole.

And Mitton notes the continuing popularity of astronomy among students.

"They're attracted by the exciting nature of the science," he says. "Not these romantic notions of spending a night on a mountain top."

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