October 13 – Earth-grazing meteoroid of 13 October 1990: A 44 kilogram, 41.5 km/s meteoroid passes above Czechoslovakia and Poland at 97.9 km. It is the first time calculations of the orbit of such a body based on photographic records from two distant places is made.
^Spurný, P.; Ceplecha, Z.; Borovicka, J. "Earth-grazing fireball: Czechoslovakia, Poland, October 13, 1990, 03h27m16sUT". WGN. 19 (1): 13. Bibcode:1991JIMO...19...13S. Aphelion of its orbit changed from 2.80 AU to 1.80 AU.
^Foote, Jennifer (1990-02-05). "Trying to Take Back the Planet". Newsweek.
^Colman, Andrew M. A Dictionary of Psychology (3 ed.). Oxford University Press. ISBN9780191726828. The illusion was first presented by the US psychologist Roger N(ewland) Shepard (born 1929) in his book Mind Sights: Original Visual Illusions, Ambiguities, and Other Anomalies (1990, p. 48), Shepard commented that 'any knowledge or understanding of the illusion we may gain at the intellectual level remains virtually powerless to diminish the magnitude of the illusion' (p. 128).