Casadastraphobia is the fear of falling into the sky. It is a relatively recently identified fear, having first appeared on urbandictionary.com on December 11th, 2006, having not previously been recorded or coined anywhere else. It is defined as an irrational or pathological fear of falling into the sky. "Cas-" is a Latin morpheme meaning "to fall," while "ad" is a Latin preposition meaning "to" or "toward." And most people recognize "-astra-" as the Latin morpheme for "star," and "phobia" as a greek word meaning "fear of." Thus, Casadastraphobia is "a fear of falling toward the stars," which is interpreted in this sense to mean, more broadly, a fear of falling toward the sky. But "-astra-" is not a etymological mistake, as many people report that their casadastraphobia is worse while they are viewing a night sky. Casasdastraphobia is, by its nature, a fantasy phobia, or a phobia for which the probability of the event described in the fear happening is zero, or near zero. This means that there is some amount of fantastical thinking involved in the precipitation of this phobia, which points to possible psychosis, as might be observed in schizotypal or schizophrenic thinking (or in bipolar disorder with psychotic features). Obsessive rumination is not beyond the realm of these disorders, and the two symptoms together can result in potentially traumatic experiences. There also seems to be some comorbidity between this phobia and vertigo, suggesting that vertigo might provoke the thinking which then becomes obsessively ruminated on, and thereby traumatizing. This is by its nature speculative, and not empirical, however, as casadastraphobia is a rather novel description of irrational fear, and has not yet made its way into broader medical discourse.