Search for evidence concerning the existence of extrasolar planets will involve both indirect detection as well as direct (imaging). Indirect detection may be possible using ground based instrumentation on the Keck telescope, Imaging probably will require an orbiting system. Characterizing other planets for complex molecules will require a large orbiting or lunar-based telescope or inteferometer. Cryogenic infrared techniques appear to be necessary. Planning for a NASA ground and space-based program, Toward Other Planet Systems (TOPS), is proceeding.
Aden B. Meinel,
Marjorie P. Meinel,
"Infrared and the search for extrasolar planets", Proc. SPIE 1540, Infrared Technology XVII, (1 December 1991); doi: 10.1117/12.48730; https://doi.org/10.1117/12.48730