The existence of these objects had long been theorised because of the gravitational forces exerted by them on our (presumed) only satellite, Luna. However, not until new research undertaken over the past two years at the Pimba Field station of the Melbourne Observatory, just 8km west of the Woomera Rocket Range in South Australia, has their true nature been discovered.
The Pimba station was a low key endeavour, only made possible for the modest funds available, by cheaply renting two rooms at Spud's Roadhouse, one being used as sleeping quarters and the other as a research lab.
A roll-off roof observatory at the back of the roadhouse contained a C14 and ST10 CCD unit which had been specially modified with customised photomultiplier giving superb sensitivity.
The search for Apogee and Perigee was prompted by a visit by Professor Manuel Labore, director of the Madrid Observatory, who had freshly come from a lecturing stint at Oxford and had noted that possible precursors of the Shoemaker-Levy impact on Jupiter had been observed in the past without the cause being determined.
He had been particularly taken by observations by the Jupiter Section of the British Astronomical Association during the late 19th Century when several members had reported the observation of black spots on the planet, smaller, but similar to those observed during the multiple cometary impact, and wondered if similar observations of strange phenomena had been recorded without the true nature of the events being determined at the time.
When at the Melbourne Observatory recently, he had been told of a new theory being developed there that Apogee and Perigee were massive, yet very small objects capable of exerting significant forces on the Moon but so small in cross section as to have so far escaped detection.
Computation of gravitational effects using the Observatory’s turbo-charged PC suggested they were in an elliptical orbit which sometimes brought them inside the Moon's orbit and actually in notional transit across the Moon's surface without so far being detected.
The most likely candidates, he decided, were very small black holes, only a metre or so in diameter and as such too small to be observed in transit even across the bright lunar surface.
Developing this idea, he considered that such objects may well have collected their own retinues from the fine meteoric material making up that body which causes the Earth's zodiacal light, and which he computed could be as much as a kilometre in diameter.
Has such a thing been observed? Yes, he decided. The British Astronomical Society publications have for more than a century contained numerous reports of Transient Lunar Objects, recorded by many experienced Lunar observers and interpreted by them as lunar outgassing, or perhaps the melting of frozen gases as the surface warms up.
Critics have formerly dismissed such sightings as spurious or mistaken. Inspired by Professor Labore's insight, Melbourne Astronomers decided to cross-reference the dates and times of such Transient Lunar Object sightings with the times at which gravitational computations inferred that either Apogee or Perigee should be in transit and found an 87 percent match.
Following this, intensive imaging was undertaken from Pimba at all forecast transit times, with multiple exposures of the same spot taken with a variety of filters and then with images stacked, enhanced, and compared with exposures of the same areas taken at non-transit times.
Using a lunar blink comparator the results were astonishing, with faint, but detectable misty objects being revealed just where they were expected to be. A combination of sunlight and moonshine when the moon was waxing turned out to reflect the most scattered light from the almost cometary nucleus, which was best seen when contrasted against dark interiors of large craters where the Sun had not then penetrated.
One can safely speculate that that although these initial findings are not actually images of black holes, they are at least evidentiary confirmation of their existence.
