The two podcast episodes provided, 'The Drake Equation (Encore)' from the 'Everything Everywhere Daily' podcast and 'Where Are All the Aliens?' from the 'Conspiracy Theories' podcast, both discuss the topic of SETI and the search for extraterrestrial intelligence.

The 'The Drake Equation (Encore)' episode explains the Drake equation, which was developed to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy. This equation is a fundamental tool used in SETI research.

The 'Where Are All the Aliens?' episode explores the Fermi paradox, which is the conflict between the high likelihood of alien life and the lack of evidence for it, a key question in SETI research.