Scientists have discovered thousands of exoplanets, including dozens of terrestrial -- or rocky -- worlds in the habitable zones around their parent stars.
Over the last several years, spectroscopic observations of transiting exoplanets have begun to uncover information about their atmospheres, including atmospheric composition and indications of the presence of clouds and hazes.
Oxygen and methane are considered to be the canonical biosignatures of modern Earth, and the simultaneous detection of these gases in a planetary atmosphere is an especially strong biosignature.
In the near future we will have ground- and space-based telescopes that are designed to observe and characterize Earth-like planets. While attention is focused on exoplanets orbiting main sequence stars, more than 150 exoplanets have already been detected orbiting red giants, opening the intriguing question of what rocky worlds orbiting in the habitable zone of red giants would be like and how to characterize them.
With the first observations of debris disks as well as proposed planets around white dwarfs, the question of how rocky planets around such stellar remnants can be characterized and probed for signs of life becomes tangible.
Habitable planets are often defined as terrestrial worlds capable of maintaining surface liquid water. As a result, atmospheric water vapor can be a critical indicator of habitability. Thus, habitability-themed exoplanet investigations emphasize detection of water vapor signatures for their targets.
A Cornell University senior has come up with a way to discern life on exoplanets loitering in other cosmic neighborhoods: a spectral field guide.
A long-term goal of exoplanet studies is the identification and detection of biosignature gases. Beyond the most discussed biosignature gas O2, only a handful of gases have been considered in detail.
Scientists have found exceptionally preserved microbial remains in some of Earth's oldest rocks in Western Australia - a major advance in the field, offering clues for how life on Earth originated.
A recent study supported in part by the NASA Exobiology Program provides further details about lipid biomarkers in stromatolites. The research focuses on microbial mat communities in ponds at Guerrero Negro, Baja California Sur, Mexico.
The Atmospheric Chemistry Experiment's Fourier Transform Spectrometer on the SCISAT satellite has been measuring infrared transmission spectra of Earth during Solar occultations since 2004.
Scientists have developed a new method for detecting traces of primordial life in ancient rock formations using potassium.
When Carl Sagan observed the Earth during a Gallileo fly-by in 1993, he found a widely distributed surface pigment with a sharp reflection edge in the red part of the spectrum, which, together with the abundance of gaseous oxygen and methane in extreme thermodynamic disequilibrium, were strongly suggestive of the presence of life on Earth.
Carbon monoxide detectors in our homes warn of a dangerous buildup of that colorless, odorless gas we normally associate with death.
Thousands of planets beyond our solar system have been discovered to date, dozens of which are rocky in composition and are orbiting within the circumstellar habitable zone of their host star.
Dutch scientists have developed an instrument capable of detecting the presence of living plants kilometres away.
With the number of confirmed rocky exoplanets increasing steadily, their characterisation and the search for exoplanetary biospheres is becoming an increasingly urgent issue in astrobiology.
NASA has awarded funding for a new interdisciplinary project called the Laboratory for Agnostic Biosignatures (LAB). The award, totaling nearly $7 million dollars, will be used to develop new, non-Earth like life detection approaches for use on Mars and on Jupiter and Saturn's icy moons.
Ecosystem-bedrock interactions power the biogeochemical cycles of Earth shallow crust, supporting life, stimulating substrate transformation, and spurring evolutionary innovation.
The high reflection of land vegetation in the near-infrared, the vegetation red edge (VRE), is often cited as a spectral biosignature for surface vegetation on exoplanets.