相关论文: Predicting biosignatures for nutrient limited bios…
The Habitable Worlds Observatory (HWO) is the first NASA Astrophysics flagship mission with a key science goal of searching for signs of life on rocky habitable exoplanets beyond our solar system. The Living Worlds Community Working Group…
The thermodynamic dissipation theory for the origin of life asserts a thermodynamic imperative for the origin of life, suggesting that the fundamental molecules of life originated as self-organized molecular photon dissipative structures…
The astrobiology is an interdisciplinary science, combining the methods and the means of physics, biology, chemistry and astronomy. Its main purpose is to find out if the exoplanets are habitable and if so, to confirm life on them. The…
Telescope missions are currently being designed which will make direct imaging of habitable exoplanets possible in the near future, and studies are needed to quantify the detectability of biosignature features in the planet's reflectance…
A long-term goal of exoplanet studies is the identification and detection of biosignature gases. Beyond the most discussed biosignature gas O$_2$, only a handful of gases have been considered in detail. Here we evaluate phosphine (PH$_3$).…
We study the prospects for life on planets with subsurface oceans, and find that a wide range of planets can exist in diverse habitats with ice envelopes of moderate thickness. We quantify the energy sources available to these worlds, the…
An important future goal in exoplanetology is to detect and characterize potentially habitable planets. Using nulling interferometry, LIFE will allow us to constrain the radius and effective temperature of (terrestrial) exoplanets, as well…
Life as we know it requires the presence of liquid water and the availability of nutrients, which are mainly based on the elements C, H, N, O, P, and S (CHNOPS) and trace metal micronutrients. We aim to understand the presence of these…
Phosphorus is an essential element for life, and the phosphorous cycle is widely believed to be a key factor limiting the extent of Earth's biosphere and its impact on remotely detectable features of Earth's atmospheric chemistry.…
Potentially habitable exoplanets are targets of great interest for the James Webb Space Telescope and upcoming mission concepts such as the Habitable Worlds Observatory. Clouds strongly affect climate and habitability, but predicting their…
Ozone is a potential biosignature and disambuguator between Earth-like and Venus-like exoplanets due to its association on Earth with photosynthetically produced oxygen (O$_2$). However, the existence of ozone in Venus's observable…
M dwarfs have long been prime targets in the search for habitable exoplanets, owing to their abundance in the galaxy and the relative ease of detecting Earth-sized worlds within their narrower habitable zones. Yet, these low-mass stars can…
The evolution of different forms of photosynthetic life has profoundly altered the activity level of the biosphere, radically reshaping the composition of Earth's oceans and atmosphere over time. However, the mechanistic impacts of a…
Some sub-Neptune planets may host habitable conditions; for example "Hycean" worlds with H2 envelopes over liquid water oceans can maintain potentially hospitable pressures and temperatures at their surface. Recent JWST observations of…
Atmospheric characterization of Earth-like exoplanets through reflected light spectroscopy is a key goal for upcoming direct imaging missions. A critical challenge in this endeavor is the accurate determination of planetary mass, which may…
Nutrient gradients and limitations play a pivotal role in the life of all microbes, both in their natural habitat as well as in artificial, microfluidic systems. Spatial concentration gradients of nutrients in densely packed cell…
(abridged abstract) Theoretical arguments indicate that close-in terrestial exoplanets may have weak magnetic fields. As described in the companion article (Paper I), a weak magnetic field results in a high flux of galactic cosmic rays to…
Future astrophysics missions will seek extraterrestrial life via transmission and direct imaging observations. To assess habitability and biosignatures, we need robust retrieval tools to analyze observed spectra, and infer surface and…
The search for habitable environments and biomarkers in exoplanetary atmospheres is the holy grail of exoplanet science. The detection of atmospheric signatures of habitable Earth-like exoplanets is challenging due to their small…
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…