The majority of ancient Greeks believed that the physical world was a tapestry of overlapping mystical and physical phenomena. To them, the fabric of reality was a combination of the Tangible and the Ethereal where Cause and Effect could be interchanged to facilitate an acceptable explanation for worldly events.
We are like the ancient Greeks in that respect. Although we have more scientific information to explain the mechanical aspects of the universe, we still rely on myth and superstition to explain a variety of strange phenomena. Ghosts, UFOs, Near Death Experiences, and Human Intuition are just a few examples of phenomena which seem to defy rational explanations. Of course, the easiest way to explain these irrational events is to simply say that the observers are: lying, crazy, stupid or intoxicated. But for anyone who has had a personal paranormal experience, the easy explanations seem to be concocted by people who are: lying, crazy, stupid or intoxicated. A mere 300 years ago, anyone who reported seeing a meteor or meteorite was placed in the lying-crazy-stupid-intoxicated category and the subject was laughably ignored by a scientific community who knew, without doubt, that rocks did not fall from the sky in our harmonious, god-willed universe.
The Greek biographer, Plutarch (46-120 CE), relates a story (Lives; Lysander; section 12) of a giant stone which fell from the sky circa 405 BCE. The fiery object was thought to be an Omen of impending doom for the Athenian navy which was preparing to fight their Spartan counterpart in the waters of the Hellespont. The Spartan leader, Lysander, was a clever commander who, by his well calculated lack of aggressive action, convinced the Athenians that he was unwilling (or afraid) to engage them in a naval battle. As Lysander continually refused to engage the Athenian navy, they became over confident and somewhat arrogant. When Lysander finally took the offensive the Athenians were caught off-guard and were utterly defeated. To any rational Greek at that time, the reason for the Athenian defeat was a combination of clever military strategy and divine intervention. The entire affair had been preordained and predicted by an Omen in the heavens. Lysander's victory over the Athenians was in accord with the will of the Immortals on Mount Olympos (Olympus) and he was simply an instrument of their divine will.
According to Plutarch, a fiery celestial body of enormous size was seen in the sky at Aegospotami in the northern Greek province of the Chersonese prior to the defeat of the Athenians. The fiery object was seen for seventy-five consecutive days before it fell to earth. It resembled a flaming cloud and followed an erratic and intricate course through the sky. As it passed overhead, flaming portions of the object were scattered in all directions but the inhabitants of the territory could find no traces of the burning fragments. People who observed the object related that the falling fragments resembled shooting stars. That conclusion seems to indicate that the Greeks knew what a meteor looked like and that the object they saw night after night was not an ordinary phenomena.
The reason that this fiery rock was considered to be an Omen is not as simple as you might assume. Lysander's victory was not just another naval battle in the long and brutal Peloponnesian War (431-404 BCE). This particular battle was the last major sea battle of the war and left the Athenian navy in ruins. It can be argued that the Athenian surrender one year later (404 BCE) was a direct result of this decisive naval battle. When Lysander attacked, with the exception of one commander, the Athenians were caught completely off-guard. As the disorganized Athenian sailors scrambled to their ships, Lysander boarded, rammed and trapped the majority of the Athenian fleet. Only nine of the 180 Athenian triremes were able to get off the beach and reach the safety of open water. Some of the Athenian sailors fled inland only to be killed or captured by the Spartans. Lysander captured 171 ships and 3,000 men in this brilliant maneuver.
There are other indications that the Athenian defeat was divinely ordained and that the fiery object was indeed sent by the Immortals to demonstrate their intentions: 1) Of the nine Athenian ships to escape the slaughter, one was the ceremonial ship, Paralos. We can assume that the fact that this ship was spared was not lost on the Athenians or the Spartans. Among its other state duties, the Paralos was used to carry emissaries to the oracle of Apollon at Delphi and thus earned the god's divine protection. 2) The fiery omen finally crashed to earth on the eastern side of the Hellespont which was the side of the waterway that the Athenians used as their encampment. It seemed obvious at the time that the fiery crash on the Athenian side of the channel meant that the doom of the Immortals was directed at Athens.
Aside from the Omen theory, one explanation which was put forth at the time was that the object was snatched from a mountain top by a storm and hurled through the upper atmosphere like a spinning top until the stone finally quit spinning and fell to earth. We are to assume that the spinning motion ignited the stone and caused the fiery display. Another, more progressive, explanation stated that the object was composed entirely of fire and when the flames were extinguished, the change in the atmosphere caused a stone to be dislodged and fall into the fields at Aegospotami. Whether the stone was dislodged from a mountain or the sky is unclear.
What is clear is that the ancient Greeks saw things which defied common sense explanations. We are like the ancient Greeks in that respect. We can perceive a mere ten percent of the Universe with our instrument-enhanced human senses and we populate the remainder of the void with figments of our imagination or assumptions based on our speculations. In the absence of tangible proof, the mystical and supernatural become, not only acceptable, but essential.