Life Beyond Earth: How will It First Be Detected? Author: Chris Impey Background: With the past decade of exoplanet discoveries, we now know there are tens of billions of habitable planets in our galaxy. The next stage in astrobiology research will be the first detection of life beyond Earth, a dramatic event in the history of science. Objective: By various approaches, the objective is unequivocal evidence of biology elsewhere. All indications are that the raw chemical materials for biology are widespread in the universe, and life needs only water, carbon-rich material, and a local energy source to begin and survive. Detection will require frontier observations, working at the limits of telescopes and remote sensing. Two extreme options are possible: that life is abundant and occurs anywhere with suitable conditions, or that there are one or more difficult or unlikely steps in evolving to a cell so life on Earth is unique or a fluke. Methods: The first detection of life beyond Earth could come from three distinct research paths. One is the exploration of habitable locations in the Solar System, particularly the surface (fossilized life) or sub-surface (extant life) of Mars, but also Europa, Enceladus and Titan. Life-detecting missions to these destinations are a decade or more away. The second is a search for biosignatures, spectroscopic indicators of the alteration of atmospheres of Earth-like exoplanets due to a microbial metabolism. Such observations will be enabled by upcoming huge ground-based telescopes like GMT and TMT, and by upcoming space telescopes like JWST. The third is a search for technosignatures, evidence of technological civilizations far from Earth. SETI is the traditional means for this search, looking for narrow-bandwidth radio signals or pulsed optical signals. Other strategies involve looking for alien artifacts or sentinels in the Solar System or detecting advanced life forms by their energy footprint or waste energy emission. Results: The feasibility and timeline of each of these approaches will be discussed, along with novel methods for life detection. Conclusions: The discovery lies in the future. The conclusion will be an educated guess to the date and means of detecting Life 2.0.