Extraterrestrial Life

A Non-specialist's Comment on Extraterrestrial Life

The affirmative statement of the existence of extraterrestrial life is tentatively raised to the status of a principle. Accordingly, Fermi's question is answered and the anthropic principle is shown to be fal-sifiable. The timescale for the development of life on Earth and the age of the universe are the fundamental quantities upon which the arguments are framed.

Concepts for Detection of Extraterrestrial Life

Microlensing and the Search for Extraterrestrial Life

Are microlensing searches likely to discover planets that harbor life? Given our present state of knowledge, this is a difficult question to answer. We therefore begin by asking a more narrowly focused question: are conditions on planets discovered via microlensing likely to be similar to those we experience on Earth? In this paper I link the microlensing observations to the well-known “Goldilo...

Extremophiles and the search for extraterrestrial life.

Extremophiles thrive in ice, boiling water, acid, the water core of nuclear reactors, salt crystals, and toxic waste and in a range of other extreme habitats that were previously thought to be inhospitable for life. Extremophiles include representatives of all three domains (Bacteria, Archaea, and Eucarya); however, the majority are microorganisms, and a high proportion of these are Archaea. Kn...

Extraterrestrial life: Life on Mars –  then and now

The recent claim to have discovered evidence of extraterrestrial life on a meteorite from Mars is not compelling, but the study nevertheless has useful heuristic value.