Il diametro di Hubble è di circa 2,40 metri, e sulla Luna non riesce a distinguere oggetti inferiori ai 100 metri. Per poter "vedere" oggetti della dimensione dei resti del LEM sulla Luna dovrebbe avere un diametro di circa 40 metri. Per vedere dettagli come la bandiera o altri strumenti così piccoli dovrebbe avere un diametro di 20 km!
The main mirror in the HST has a diameter of 2.4 meters. Visible light has an average wavelength of about 0.5E-6 meters. The Moon is at a distance of 3.8E8 meters. Putting these numbers into the formula gives the size of the smallest feature that the Hubble Space Telescope can resolve on the Moon's surface. It is just under 100 meters. Flags are seldom this big, so Hubble Space Telescope images of the Moon can not resolve the flags or other objects left behind by the Apollo astronauts. To recognize a flag and see details, such as stars and stripes, would require resolving details as small as about a centimeter. This resolution would require a space telescope with a diameter of about 20 kilometers.