Proof of extraterrestrial intelligence in space may be quite close to home. The Cydonia region on our closest planetary neighbour, Mars, seems to meet all the requirements. In this area, several artefacts of extraterrestrial origin have been discovered. These include, amongst others:

Mars Odyssey 2001 Themis Infrared pictures, published in the fall of 2002 indeed confirm the existence of a whole city. (See:

Even though the first pictures that revealed these artefacts were only made by the Viking probe in 1972, there are strong indications that the US Government and NASA already knew of their existence in 1961, when the so-called Brookings Report referred to possible discovery of such artefacts on the moon, Mars and Venus. (Brookings Report, p. 215 - See Brookings Report for more information).