In Scientific American magazine for 25 August 1906 appears this letter, written just before H. P. Lovecraft turned sixteen years old:
To the Editor of the Scientific American:
In these days of large telescopes and modern astronomical methods, it seems strange that no vigorous efforts are being made to discover planets beyond the orbit of Neptune, which is now considered the outermost limit of the solar system. It has been noticed that seven comets have their aphelia at a point that would correspond to the orbit of a planet revolving around the sun at a distance of about 100 astronomical units (9,300,000,000 miles).
Now several have suggested that such a planet exists, and has captured the comets by attraction. This is probable, as Jupiter and others also mark the aphelia of many celestial wanderers. The writer has noticed that a great many comets cluster around a point 50 units out, where a large body might revolve. If the great mathematicians of the day should try compute orbits from these aphelia, it is doubtful if they could succeed; but if all the observatories that possess celestial cameras should band together and minutely photograph the ecliptic, as is done in asteroid hunting, the bodies might be revealed on their plates. Even if no discoveries were made, the accurate star photographs would almost be worth the time and trouble.
H. P. LOVECRAFT
There exists, at least in hypothetical fancy, an alternate time-track wherein Howard Phillips Lovecraft (1890-1937) concentrated his lifelong scientific interests into a career as gentleman-astronomer rather than gentleman-writer. Science was a major interest of Lovecraft's, and in his youth, astronomy above all.
In the Introduction to Lovecraft's Miscellaneous Writings, his modern editor S. T. Joshi says:
... masses of Lovecraft's juvenile scientific journals, notably The Scientific Gazette (1899-1904) and The Rhode Island Journal of Astronomy (1903-07), survive ...
Science was at the foundation of Lovecraft's entire nonfictional writing — perhaps even his literary work as a whole — for a strain of scientific logic and reasoning is evident even in his literary essays.
On our local worldline, Lovecraft became a highly original and imaginative fantasist. Others with a different bent for patient detail concentrated on astronomy. The young amateur astronomer Clyde W. Tombaugh, using a blink comparator on pairs of starfield photographs, in 1930 discovered elusive Pluto out beyond Neptune. (The New Solar System has some fascinating detail on Pluto and its satellite Charon.)
In the introduction to the "Epistolarian" section of Miscellaneous Writings, Joshi says of the 1906 Scientific American letter above:
A quarter of a century later Lovecraft would utilize in fiction the new planet that had been discovered by means not entirely dissimilar to those outlined in this letter: Pluto becomes the dark planet Yuggoth in "The Whisperer in Darkness" (1930).
That story is included in The Dunwich Horror and Others. In a science-minded philosophical essay, Lovecraft wrote:
It seems [...] that all matter is in a state of balance betwixt formation and disintegration — evolution and de-volution — and that the infinite cosmos is like a vast patch of summer sky out of which little cirrus clouds gather here and there, presently to be dissolved into blankness again. The universes we know correspond to the little cirrus clouds of that summer sky [...]
"The Materialist Today", 1926
Almost certainly we gained a far greater writer in Lovecraft's known career as reporter of the outre and macabre underpinnings of existence, than we lost in his not becoming a gentleman-astronomer of the spacious skies. But if he had stuck with astronomy, what might he have seen out there?