Every person is a competent witness unless a statute or a rule of evidence provides otherwise.

United States v. Mitchell, 365 F.3d 215, 243 n. 22 (3d Cir. 2004) ("[N]o no one would argue that the commercial popularity of astrology for non-judicial use makes it fit for admission under Rule 702.").Astrology is not a valid science and "expert" astrological evidence does not satisfy the admissibility requirements under Federal Rule of Evidence 702 or comparable State rules; astrology is "junk science."

Threadgill v. Armstrong World Industries, Inc., 928 F.2d 1366, 1375 (3d Cir. 1991) (holding, in plaintiffs widow and children's action against defendants for asbestos-related negligence, that the trial court erroneously excluded into evidence....Federal Rule of Evidence 803(16) and comparable State rules create a hearsay exception for statements in an authenticated document that is more than a certain number of years old, typically twenty years.

Fed. R. Evid. 804.Statements that fall within an exception to the hearsay rule are admissible to prove the truth of the matter asserted by the declarant (the maker of the statement).