Now there is a new image, equally profound and startling. Taken by the Hubble Space Telescope, it is our deepest ever look into space. The scientists in charge of the Hubble kept the telescope's "shutter" open for an unprecedented ten-day exposure. In the postage-stamp-size patch of space they surveyed, they discovered thousands of galaxies - star-cities like our Milky Way - that are millions of times fainter than the naked eye can see. Their light has taken so long to reach us that we see them, not as they are today, but billions of years ago, when they were cosmic babes-in-arms. The picture which ordinary earthlings saw just a few weeks ago on television and the front pages of newspapers spoke of so many things: beauty, the scale of space, origins. It took the world by storm.
A generation or two ago, many intelligent, arts-educated people saw astronomy as an arcane subject that at least kept white-bearded old men off the streets. It was all right for children, but it was "something you grew out of". I have found that many adults are in fact frightened of astronomy. But the excitements of space technology, and the need to set the world in a wider context, have overcome that fear. A growing number of people have developed a fascination with the surrounding cosmos, and are asking the questions that are raised by our existence in it.
In the recent history of cosmic sensations, some very public failures have interrupted that upswing of enthusiasm. About ten years ago, Halley's Comet came on the brief visit to the inner Solar System that it makes every 75 years. Astronomers knew that Halley, passing far from the earth this time, would be a damp squib (and said so). But the media, and those out to make a fast buck, hyped things up. Most people felt cheated that they hadn't seen the celestial sight of the century, and, naturally, blamed the astronomers.
Then it was discovered that the supposedly-perfect mirror on the $1.4 billion Hubble Space Telescope was warped - returning images that, in the words of one expert, looked like "squashed spiders". The explosion of space shuttle Challenger a few years earlier - although not strictly an astronomical event - had also contributed to the public's disaffection. Astronomy is only exciting when it's onwards and upwards.
I can remember when the tide against those disappointments began to turn. It was December 1993, and I was in Houston, covering the Hubble Space Telescope repair mission for television. The images of the astronauts on the screen were pure Dan Dare - and we had space heroes again.
Seven months later, we had another space spectacular - this time a natural event. For the first time in history the world watched, gobsmacked, as 21 separate pieces of the dismembered comet Shoemaker-Levy 9 cannoned into Jupiter. Although by far the biggest of the planets, Jupiter did not get off lightly. If it had happened to us, it would literally have been the end of the world.
More daring space exploits came in 1995: the well-televised docking of the US shuttle and the Russian Mir space station, and the descent of NASA's Galileo atmosphere probe into the churning clouds of Jupiter. And the Hubble managed to capture one of the most aesthetically beautiful pictures of all time: eerie stalactites of gas surrounding a star being born.
This year has got off to a flying start. Hot on the heels of their ten- day gaze into the depths of the universe, the Hubble scientists released more glorious images - this time of stars in their death-throes. A couple of days later, astronomers in California announced the discovery of planets around two nearby sun-like stars, reviving the whole debate on whether there is life out there. Coinciding with this hubbub of activity, BBC Radio 4 ran a two-month-long "Journeys into Space" season, featuring fiction, fact, drama and discussion, all loosely based around space and astronomy. The programmes were a runaway hit. It was definitely OK to be interested in astronomy.
Apart from the era of the moon landings, I have never known a time when public enthusiasm for matters celestial has run so high. Even acquaintances of mine among the chattering classes are now asking questions - without a cynical gleam in their eye.
Why this upsurge of interest? For a start, I think it comes down to brilliant pictures in the papers and riveting images on the screen. Secondly, people are now ready to look beyond the Earth, and to wonder how they fit into the cosmic scheme of things. Most important of all, they now feel that they can understand what is going on out there. Thanks to space technology, the inaccessible has been made accessible.
The "new astronomers" out there are not anoraks who log sky-sights like train numbers. Some of them may stargaze - I hope they do, for the sight of a truly dark, star-filled sky is one of the most beautiful in the world - but, in the approach to the millennium, they also want answers to the Big Questions. They read astronomy to discover philosophy on its grander scale.
The pace of interest in heavenly matters will not slacken. There are two total eclipses of the moon (April and September); a storm of shooting stars (August); and a major new comet (late March) that promises to be the brightest for 20 years. Next year will bring what may be an even brighter comet. And there's always the chance of the completely unexpected. Just watch this space.
Heather Couper is Gresham Professor of Astronomy and a former president of the British Astronomical Association. She also runs Pioneer TV Productions; recent 'Equinox' successes include 'On Jupiter', 'Avalanche', and 'Electric Skies'Reuse content