A description (with a little rationalization and expansion) of Philip Reeve's rah-ther delightful "Larklight" trilogy universe. en.wikipedia.org/wiki/Larkligh…
The Aether currents circle around the sun, a jolly good thing, too, because if the Aether were a static medium, the planets would soon fall into the sun. As it is, the currents help move the planets in their orbits, and ease the passage of space ships travelling clockwise rather than counterclockwise around the sun. The Aether is an energetic medium, the basis for the Alchemical drive, and sustains the fauna of space much as air sustains terrestrial life; however, the traveler should keep in mind it cannot substitute for oxygen for long, and one needs to bring a supply along when venturing into space.
The solar system is well supplied with suns and planets: as in many other solar systems,  this is not a natural phenomenon but the work of a member of the ancient and slightly eldritch super-race known as the Shapers, tasked billions of years ago by the unknowable to create the conditions necessary for life to flourish in the greatest richness and variety.
(This Solar System’s Shaper, rather than expiring as normal upon the completion of her task, stuck around to watch things develop, and eventually, after four and a half billion years, ended up settling down as Mrs. Edward Mumby, wife and mother, a fact so hard to believe that although she has told several important personages of the fact, they have assumed it was a mere joke hiding some probably Sinister Truth).
Anyway, she did a bang-up job, since solar system is well populated out to the limits of present exploration, which now extends as far as the seventh planet, even Mercury having its own curious plants and animals in the twilight zone between the fiery and frozen hemispheres. Earth, the Moon, Venus, Mars, the Asteroid Belt, Jupiter and its Moons, Saturn’s Moons and Rings, and the damp and soggy air/water boundary of Uranus (Georgium Sidus for those who worry about mispronunciation) all possess intelligent life, in most cases more than one kind of intelligent life (a minimum of nine, with a couple more doubtful cases, for Jupiter’s moons alone). The level of intelligence is of course always debatable but then the British always find reports of other intelligent life on the other side of the channel, let alone across the sea of space, debatable. What natives of the Washington-Roosevelt-Obama timeline call Neptune is here known “Hades” (A gloomy planet with a gloomy moon and home mostly to lichen, it has recently been settled by a race arriving from interstellar space: what they call it is not exactly pronounceable in proper British, but will probably eventually be reinterpreted in a more useable form, like all those Frenchie-named places about London). Recent evidence indicates a still further planet or possibly outsized asteroid, as yet barely resolvable by telescope.
The dominant planet is currently Earth, which is to say, the British Empire, ruler of the waves both aquatic and aetheric, thanks to the genius of Isaac Newton, who after figuring out gravity, the spectrum, and calculus went on to master the principles of Alchemy (or did he?). Much to his disappointment, he failed to discover the secrets of immortality, but as a consolation prize he created the Alchemical Engine, which when combined with the development of the artificial gravity enhancer or diminisher, combining alchemical principles with the Laws of Gravitation, opened Outer Space to Great Britain, with the first expedition to the Moon, led by Captain Frobisher, taking place as early as 1703.
While the Gravity Generator is a simple device, requiring a few basic elements, some magnetic materials, and a coal or phlogiston stoked furnace, the alchemical drive is a far more complicated matter, which is why it has long been successfully kept secret by the British government and the Government-controlled Guild of Alchemists, requiring many complex elements, complicated mechanical contrivances, and a keen understanding of such things as the temperature of your alchemical furnace, the local aether flux, the positions of the nearest planets, and various other factors which act to influence the alchemical reaction. These things make the difference between a working alchemist and a smear of jam dispersing in space.
When all is functioning, an alchemical engine sings with the Music of the Spheres, and emits a golden glow, as the ship is propelled through space at amazing speeds. Once the engine has reached a certain power level, the alchemical glow will form a luminous bubble around the ship, carrying it from the purely physical world to the plane of Alchemical space, which besides sounding mighty impressive protects the passengers from the forces of acceleration and makes the ship largely impalpable to objects in its path, allowing it to pass right through anything smaller than a fair-sized asteroid (or another alchemically driven ship. What exactly happens when two alchemical craft “riding Sir Newton’s Golden Roads”, as it is often called, collide at speed is unknown, since nobody has survived to report on the situation). At current maximum speeds, a ship can reach Georgium Sidus in a matter of weeks – although theoretically the top speed of an alchemically driven ship is limited only by the speed of light- and according to some admittedly eccentric theorists, perhaps not even that.
As far as terrestrial historians and archaeologists can tell, although other races have developed other methods of crossing space, and may have visited Earth in the distant past, all Britons are pleased as punch to know that we appear to be the first to perfect travel through the use of alchemical principles (well, except for the White Spiders. But they’ve had over four billion years to work it out, and being the scoundrels that they are, they probably stole it from someone else, anyway).
Given that it appears almost impossible to work out Alchemy from first principles – which makes Newton even more of a demigod in the eyes of his countrymen - it would be a long time – nearly a century’s worth of spying, theft, bribery, and the occasional traitorous British alchemist (colonials and Welshmen all, no doubt) - before the other nations of Europe succeeded in developing alchemical science of their own, and even as of the mid-1850s, the Alchemical Engines used by the French and Russians are of inferior quality to those used by the British, making their space ships terribly slow and lumbering by British ships, taking months to reach Jupiter, and unable to achieve the true Golden Roads, leaving them at perpetual risks of colliding with a space manatee or something similar. Combined with the impossibility of coordinating naval forces with such long spans of time and poor communications, the British space navy has so far remained almost unchallenged. While Britain rules Mercury, Mars, the Moons of Jupiter and the more colorful asteroids, and lays as yet unchallenged (mostly) claim to Venus, France, Russia, and Greater Austria are largely confined to minor specks and flecks of rock here and there in space, or are forced to lease areas on the British-controlled planets. (Such states as Holland and Prussia don’t even try to compete, being satisfied with access to the markets of British worlds).
As well as the planets, Britain also rules much of the earth, its ability to reach anyplace on the planet unchallenged for many years allowing it to gain control of such rich prizes as India, the East Indies, and most of North America. Later, the ferocious self-policing and government control of the British Alchemists Guild meant that aside from a handful of traitors, there was nobody in the American colonies able to control a flying warship, giving Britain virtually total mastery of the skies and crushing the foolish Rebellion of ’76.There has also been some colonization of Africa, mastery of gravity allowing the British to circumvent pestilent lowlands and settle healthier highlands, but generally speaking the returns have been low enough that the Crown has decided to let the other European nations do what they can with the majority of the Dark Continent.
Today, the world is divided between the British Empire, the Franco-Russian alliance, and everyone else. Prussia, the sociopathic genius of OTL having been butterflied away, remains a middling power of strictly regional importance, while the Austrians play a long game of influence and dynastic roulette in the German and Italian states, always with one eye on the French Republic and its dangerously radical notions. Control of the Black Sea straits having become somewhat pointless when the Russians developed their own (initially rather dangerous to the user) version of the alchemical engine, Britain tolerated the Austrians and the Russians breaking up the Ottoman Empire, although it insisted upon (and got) its own "Lion's share" of the cake.
China found it could not stop British armed merchant ships landing in even their most remote provinces and cutting out the middle man, and after a series of utterly humiliating conflicts with an enemy that could wreck Chinese cities without even being touched, became a virtual British protectorate: the collapse of the dynasty that followed once the people decided the Manchu (less secure than they would have been a century later) had lost the Mandate of Heaven eventually scattered Chinese refugees across the solar system. China remains disunited, although in the last couple decades a government has emerged in the north which, if not able to effective enforce its authority through all of the country, at least is reliable enough to deal with. Initially friendly, relations have cooled since the Chinese began deploying some crude Aether ships of their own, most likely with French and/or Russian help.  The notion of China being reunified as a cat’s paw of their almost effective enemies sends chills through the British ruling classes.
India is similar to OTL, although with easier transport there has been more European settlement (still a drop in the bucket), and the British are even more insufferably superior than OTL. The order and stability of the Japanese Shogunate was interrupted by large numbers of ships filled with heavily armed Cossacks dropping out of the sky: Russia has made a protectorate of Japan, if an undeniably troublesome and restless one.
France, in spite of the US revolution turning out to be a bit of a damp squib, still had its own Revolution, with plenty of head-chopping: it avoided Napoleonic rule (and France thereby avoided bombardment by the British air and space navy ), and after a brief flirtation with the Bourbon ex, returned to the follies of Republicanism. It currently leads an oddball alliance of minor Republican regimes in Germany, Italy and those parts of Latin America the Spaniards were unable to hold onto. It is an authoritarian semi-democracy, and is always ready to stir up trouble in British America and elsewhere, although out of strategic considerations it is allied to autocratic Russia , power politics and British global dominance making for strange bedfellows.
Spain was unable to duplicate the British alchemical drive, and a knockoff of the Russian version really wasn’t enough to turn the tide when their colonies started rising in revolt over efforts by the Spanish government to centralize and modernize colonial administration. As of 1853, much of Latin America has been lost, and the Crown still holds a disparate bunch of bits and bobs of territory whose main unifying factor that they’re much easier to get to even with a crappy Aether ship than they are by colonials with boats and horses and ox carts (and the occasional balloon).
The British continue to have some trouble with the American colonies: the old revolutionaries were dying off, the economy booming and things looking better than they had in decades when the whole abolition thing broke, and the southern colonials raised strident and occasionally projectile-driven objections to a 20-year program for replacing the old, immoral, backwards system of slavery with the new, modern, scientific system of debt indenture, long-term labor contracts, and pass laws. All in all, the “southern rising” was only a minor challenge to the power of the empire, given that few northerners and of course none of the blacks in question supported it, and was all over by ’48 (a well known German comic called it “history replayed as farce”), but it has brought all the weirdoes out of the woodwork, encouraged the bomb-throwing anarchists and radical republicans, shaken the Imperial economy, and led to many irate letters to the Times by property rights fundamentalists.
(Socialism is still jelling as a phenomenon, but anarchism, given some intellectual coherence by Russian thinkers and some extremist Republicans in France, is an energetic if mostly underground movement across Europe and beyond)
Many British still take the Grand Tour of Europe, to enjoy the quaint sights of that somewhat antiquated continent: those who do not fancy air travel will find their trip facilitated by the web of rails that crisscrosses the continent, and now that the Channel Bridge has been completed, one may travel from London to Vienna in the comfort of a British-made railcar. (Alas, the Russians
still insist that you change over to one of their distressingly primitive and malodorous trains once one reaches their border, so generally only those accustomed to roughing it go on to St. Petersburg or Moscow. And, unless one is actually participating in a military invasion of that benighted nation, there is no choice but to take one their own rather unsafe air machines to pass over their territory.).
Britain, and more specifically London, is the center of the Empire, and, at least in British eyes, of the solar system. Thanks to the development of air travel (and early railways as well- phlogiston powered steam machinery was in operation several decades before OTL), transportation in and out of the city has become a lot easier than it was in the first half of other people’s 19th centuries, and the population has exceeded five million nearly forty years earlier. (Although a fair number of people are now moving out of the city, in nervous expectation of further alien attacks). The air is cleaner with the increasing use of phlogiston stoves and the movement of much industry off-world or to the colonies, and the sky swarms with flying machines. Another notable sight is the Space Elevator: rather than a landing field that would take up expensive land, Isambard Brunel has made an ingenious use of antigravity to create an almost weightless tower three miles high at the mouth of the Thames, so ships can unload their passengers at docks ranged vertically. A great deal of damage was done by first the White Spider’s giant mechanical spider (cleverly assembled under British noses in its disguise as the Crystal Palace) and then by the Mothstorm/Sssnilth invasion, but plucky Londoners (those who aren’t running away) are once again busy with reconstruction, and given the size of the city, the actual percentage of it lying in rubble is really quite low. (Admittedly, it is a bit less architecturally notable than before, in that the spider-machine’s pilot was quite enthusiastic about attacking anything that looked like a prominent public building).
In spite of Doubting Thomases pointing out all the new discoveries not anticipated by the Bible, the British remain a religious people, and the Church has been fired up by the prospects of converting the heathen masses of outer space (although at this point, somewhat embarrassingly, the only race showing any signs of converting en masse to Anglicanism is one of the more minor Jovian ones). The Catholics also have been doing their best, with even less luck, while the Russian Orthodox still hold that aliens have no souls (making a good excuse for enslaving and/or slaughtering any races the Russians get an exclusive hold over. God bless the British space-navy!). Technology and industry work to support the modern preacher, with the waterproof, toxic-gas proof, and corrosion-resistant bible now distributable in any environment, while for the preacher with limited space aboard ship, a variety of new Portable Pulpits have been devised which can be ingeniously folded and packed into a very small space, and easily reassembled into a proper preacher’s perch both high and elegantly ornamented with arches, vines, leaves, grapes, etc.
Orthodox Jews remain divided on whether all alien life forms are treif or not, so it remains to be seen whether aliens will have to worry about being eaten by Jews (Christians they already worry about: in the history of space exploration there have been some unfortunate incidents involving stranded crews of starving rough-hewn space-sailors and not immediately obviously sentient natives.)
Terrestrial women have advanced in their status in recent decades, and now may pursue a variety of careers, such as teachers, nurses, housekeepers, magazine editors, and teachers, but traditional roles still dominate, in spite of reports of the peculiar gender relations of alien species. Ethics remain perhaps a trifle shaky by pan-dimensional standards: if mechanical urchins now clean the harder to access chimneys, many biological ones still live off what they can find to sell while sorting through sewer waste. Although slavery has been eliminated, the government’s treatment of its subject peoples does not always match up with what it metes out to the average male Londoner with a guaranteed income, very few of which are forced into corvee labor or impressed to serve on distant planets or become the subject of medical experimentation without permission: and blacks and Arabs, being human beings, are more likely to be protected by the law than, say, a savage Anemone-person from the wilds of Ganymede.
Before we explore the various planetary and sub-planetary bodies, a note on space: it is most definitely not empty. It is indeed a vast sea, the Aether and the radiance of the sun sustaining a great variety of space-plants, upon which a variety of space-dwelling animals feed where they do not feed upon each other. Icthyomorphs are the most commonly seen animals, so named due to their fairly inexplicable resemblance to Earth fish (some attribute this to God running out of ideas): their fins are charged with negative Aetheric energies which they use to propel themselves through the Aetheric currents, similarly to the wing designs of the most advanced new space ships (Wings are of course not used by alchemically powered ships in space for speed, but for maneuvering and landings – admittedly, some crude anti-gravity and coal-furnace atmosphere-only ships sans alchemists do use wings for propulsion, and jolly slow they are). Space plants are usually limited in size due to the shortage of raw material in space, with the larger specimens usually rooted in some space rock, comet, or asteroid. Certain Space Pests are a problem to those who choose to build their castles in the Aether. Space barnacles and Space weed will of course take root in any ship which travels through the more life-rich parts of the solar system. The dreaded Pudding Worm (which does not, in fact, looks like a worm at any stage of its life) has happily made the transition from parasitizing and mimicking the Space Pudding (the fruit of the asteroidal Bong-Bong tree) to infecting and devouring all forms of pudding-type confections known to British cooks. Space Bats of an alien sort can also be a nuisance.
In some areas, space-weed or space-reefs may be dense enough to offer a serious danger to those not travelling at full alchemical speed, as mentioned earlier: such areas are carefully plotted and charted. For foreign ships, heavy prow armor is a must (which of course makes them even slower and more lumbering). Many space plants and animals are of economic value: there is a considerable space-fishing industry, and the cultivation of the singing varieties of space flowers is the current botanical frenzy. Of course, there are some dangerous space-animals, although aside from the Sun Dogs (a monstrous space-snake composed of transparent jelly, fortunately only found well within the orbit of Venus) few are a risk to a fair-sized alchemical ship, although there are some parts of the solar system where dawdling off the Golden Road is not encouraged.
Although diminishing near the sun where the radiation is too intense, and out past the farthest planets, where light is dim and the Aether is thin and cold, total mass of space-dwelling life is estimated to greatly exceed that of planetary life, leading some to suggest that space, not planetary surfaces, is the true center of creation: most scientists and philosophers consider this view to be a bunch of dingoes kidneys. As far as is known, there are no purely space-dwelling intelligences, although there are all sorts of spooky old spacemen’s tales.
 Some solar systems form just fine on their own, it is true. But others need a little tinkering to prevent such silliness as forming gas giants so close to the sun that they boil, planets with rains of molten glass, etc. And certain early-bird species will think that just because they’re first evolvers they get to hog all the mass in the universe…
 The Chinese claim that the alchemical engine was independently duplicated by Chinese alchemists: British scholars scoff at the notion that a bunch of superstitious Asiatics could duplicate the work of the great Newton. They're half right, but not for the reasons they think.
 The Greatest Empire That Ever Was was not particularly alarmed by the armies of the Revolution, and felt it could tolerate wee France doing a wee bit of expansion of its pinched borders in Europe, as long as they didn’t make a habit of it.