One night in 1781, as William Herschel was peering through his telescope, he saw "a star that appeared to be visibly larger than the rest." It turned out to be the planet that we now call Uranus.
The discovery brought Herschel fame and then a knighthood, and such was the general excitement of the populace in the years that followed that enterprising owners of a telescope could make a pretty penny by allowing passers-by to view the heavens. But according to William Wordsworth, writing in 1806, the results were often disappointing:
Whate'er the cause, `tis sure that they who pry and pore
Have little gain, and seem to be less happy than before;
One after one they take their turn - nor have I one espied
That doth not slackly go away, as if dissatisfied.
But not so nowadays. Again I am indebted to Dr Ian Elliott for bringing to my attention the euphoria that exists among those who have been "peering" at Uranus through the Hubble Space Telescope and who, for the past five years, have been making a time-lapse film of the slow advance of the Uranian spring.
The seasonal changes here on Earth are caused by our planet's axis being tilted. Consequently, the Earth's southern and northern hemispheres are alternately tipped towards the Sun and then away from it, as the Earth progresses on its orbit.
Uranus, however, is tilted completely over on its side, with its axis "horizontal", as it were, and as it proceeds on its 84-year journey around the sun each pole is first exposed to continuous sunlight for 42 years, and then languishes in the seeming endless night of a long, dark, frigid winter.
The "northern" hemisphere of Uranus is just now coming out of the grip of the winter it has been experiencing for decades. The planet does not have a solid surface, but is instead a ball of mostly hydrogen and helium, topped by an icy cloud of frozen methane. It is this methane - a gas which absorbs red light and reflects the blue and green - that gives the planet its characteristic blue-green colour.
As the sunlight reaches lower latitudes, it is warming an atmosphere which the film shows to be coming out of a frigid hibernation and stirring back to life, with warm bubbles of methane welling up from deep below.
Huge storms lash the previously tranquil regions of the planet. Uranus, once considered one of the most bland locations in our neighbourhood, is now revealed by this latest Hubble movie to be a dynamic world which boasts the brightest clouds in all the outer solar system.