Recently in the Biosignatures & Paleobiology Category


The habitable zone (HZ) describes the range of orbital distances around a star where the existence of liquid water on the surface of an Earth-like planet is in principle possible.

The Earth's albedo, or reflectance, is a fundamental atmospheric parameter having deep implications for temperature and climate change. For that reason, experiments have been performed to monitor it over the past two decades to reveal how it evolves.

Carbon, nitrogen, and oxygen (CNO) are key elements in stellar formation and evolution, and their abundances should also have a significant impact on planetary formation and evolution. We present a detailed spectroscopic analysis of 74 solar-type stars, 42 of which are known to harbour planets.

In 1990, Voyager 1 captured the most distant portrait of our planet ever taken, revealing that from beyond Pluto's orbit, Earth appears as nothing more than a "pale blue dot."

Using Clouds to Map Life

Clouds may seem like distant, ephemeral features that have little to do with life on Earth. In fact, they affect everything from the viability of ecosystems, to how much carbon plants absorb, to the reproductive success of reptiles.

The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the Martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually.

Circumstellar debris disks are the extrasolar analogues of the asteroid belt and the Kuiper belt. They consist of comets and leftover planetesimals that continuously collide and produce circumstellar dust that can be observed as infrared excess or in resolved imaging.

In order to identify inhabited worlds beyond the Solar System, scientists are exploring the possibility of detecting gases that could serve as biosignatures in the atmospheres of extrasolar planets.

Are we alone in the universe? To answer this question, astronomers have been using a variety of methods in the past decades to search for habitable planets and for the signals from extraterrestrial observers.

The planned launch of the James Webb Space Telescope in 2018 will herald a new era of exoplanet spectroscopy. JWST will be the first telescope sensitive enough to potentially characterize terrestrial planets from their transmission spectra.