Results 11 to 20 of about 8,849 (202)

Surface and Temporal Biosignatures [PDF]

, 2018
Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal exoplanet biosignatures, reviewing Earth analogues and proposed applications based on observations and models.
arxiv   +9 more sources

Alternative Methylated Biosignatures I: Methyl Bromide, A Capstone Biosignature [PDF]

ApJ 938 6 (2022), 2022
The first potential exoplanet biosignature detections are likely to be ambiguous due to the potential for false positives: abiotic planetary processes that produce observables similar to those anticipated from a global biosphere. Here we propose a class of methylated gases as corroborative `capstone' biosignatures.
Michaela Leung, Edward W. Schwieterman, Mary N. Parenteau, Thomas J. Fauchez   +3 more
arxiv   +6 more sources

Exoplanets: Possible Biosignatures [PDF]

Proceedings of Frontier Research in Astrophysics – II — PoS(FRAPWS2016), 2017
The ancestor philosophers' dream of thousands of new worlds is finally realised: about 3500 extrasolar planets have been discovered in the neighborhood of our Sun. Most of them are very different from those we used to know in our Solar System.
Claudi, R.
core   +3 more sources

Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment [PDF]

Astrobiology, 2017
Here we review how environmental context can be used to interpret whether O2 is a biosignature in extrasolar planetary observations. This paper builds on the overview of current biosignature research discussed in Schwieterman et al. (2017), and provides an in-depth, interdisciplinary example of biosignature identification and observation that serves as
Karl R. Stapelfeldt, Edward W. Schwieterman, Heike Rauer, Christopher T. Reinhard, Christopher T. Reinhard, Victoria S. Meadows, Victoria S. Meadows, Siddharth Hegde, Timothy W. Lyons, Timothy W. Lyons, Russell Deitrick, Russell Deitrick, Shiladitya DasSarma, J. Lee Grenfell, M. N. Parenteau, M. N. Parenteau, Giada Arney, Giada Arney, Jacob Lustig-Yaeger, Jacob Lustig-Yaeger, N. Siegler, Shawn Domagal-Goldman, Shawn Domagal-Goldman, Andrew P. Lincowski, Andrew P. Lincowski, Norio Narita   +25 more
arxiv   +9 more sources

A Review of Exoplanetary Biosignatures [PDF]

Physics Reports, 2017
We review the field of exoplanetary biosignatures with a main focus upon atmospheric gas-phase species. Due to the paucity of data in Earth-like planetary atmospheres a common approach is to extrapolate knowledge from the Solar System and Early Earth to Earth-like exoplanets. We therefore review the main processes (e.g.
arxiv   +5 more sources

Atmospheric Seasonality as an Exoplanet Biosignature [PDF]

Olson S.L, Schwieterman E.W., Reinhard C.T., Ridgwell A., Kane S.R., Meadows V.W., Lyons T.W. (2018) Atmospheric Seasonality as an Exoplanet Biosignature. Astrophysical Journal Letters 858: L14, 2018
Current investigations of exoplanet biosignatures have focused on static evidence of life, such as the presence of biogenic gases like O2 or CH4. However, the expected diversity of terrestrial planet atmospheres and the likelihood of both false positives and false negatives for conventional biosignatures motivate exploration of additional life ...
Victoria S. Meadows, Victoria S. Meadows, Andy Ridgwell, Andy Ridgwell, Stephanie L. Olson, Stephanie L. Olson, Stephen R. Kane, Stephen R. Kane, Christopher T. Reinhard, Christopher T. Reinhard, Edward W. Schwieterman, Timothy W. Lyons, Timothy W. Lyons   +12 more
arxiv   +8 more sources

Biosignatures Associated with Freshwater Microbialites [PDF]

Life, 2020
Freshwater microbialites (i.e., lithifying microbial mats) are quite rare in northern latitudes of the North American continent, with two lakes (Pavilion and Kelly Lakes) of southeastern BC containing a morphological variety of such structures.
Richard Allen White, Sarah A. Soles, Allyson L. Brady, Gordon Southam, Darlene S.S. Lim, Greg F. Slater   +5 more
doaj   +4 more sources

An Overview of Exoplanet Biosignatures [PDF]

arXiv
This chapter reviews proposed exoplanet biosignatures, including their biological origins, observable features, atmospheric sinks, and potentially confounding abiotic sources. Emphasis is placed on material published since past comprehensive reviews while providing a foundational understanding of each named biosignature. Topics include possible gaseous
Schwieterman, Edward W., Leung, Michaela
arxiv   +3 more sources

On biosignatures for Mars [PDF]

International Journal of Astrobiology, 2021
AbstractIn this work, we address the difficulty of reliably identifying traces of life on Mars. Several independent lines of evidence are required to build a compelling body of proof. In particular, we underline the importance of correctly interpreting the geological and mineralogical context of the sites to be explored for the presence of ...
Westall, Frances, Hickman-Lewis, Keyron, Cavalazzi, Barbara, Foucher, Frédéric, Clodoré, Laura, Vago, Jorge   +5 more
openaire   +3 more sources

Is There Such a Thing as a Biosignature?

Astrobiology, 2023
The concept of a biosignature is widely used in astrobiology to suggest a link between some observation and a biological cause, given some context. The term itself has been defined and used in several ways in different parts of the scientific community involved in the search for past or present life on Earth and beyond. With the ongoing acceleration in
Malaterre, Christophe, ten Kate, Inge Loes, Baqué, Mickael, Debaille, Vinciane, Grenfell, John Lee, Javaux, Emmanuelle J., Khawaja, Nozair, Klenner, Fabian, Lara, Yannick J., McMahon, Sean, Moore, Keavin, Noack, Lena, Patty, C.H. Lucas, Postberg, Frank   +13 more
openaire   +7 more sources