Related papers: Five or six step scenario for evolution?
Recent detections of carbon-bearing molecules in the atmosphere of a candidate Hycean world, K2-18 b, with JWST are opening the prospects for characterising potential biospheres on temperate exoplanets. Hycean worlds are a recently…
Evolution is the theory that plants and animals today have come from kinds that have existed in the past. Scientists such as Charles Darwin and Alfred Wallace dedicate their life to observe how species interact with their environment, grow,…
Conventional definitions of habitability require abundant liquid surface water to exist continuously over geologic timescales. Water in each of its thermodynamic phases interacts with solar and thermal radiation and is the cause for strong…
We propose a novel definition of life in terms of which its emergence in the universe is expected, and its ever-creative open-ended evolution is entailed by no law. Living organisms are Kantian Wholes that achieve Catalytic Closure,…
The ultimate climate emergency is a "runaway greenhouse": a hot and water vapour rich atmosphere limits the emission of thermal radiation to space, causing runaway warming. Warming ceases only once the surface reaches ~1400K and emits…
The magma ocean (MO) is a crucial stage in the build-up of terrestrial planets. Its solidification and the accompanying outgassing of volatiles set the conditions for important processes occurring later or even simultaneously, such as…
The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this…
Early Mars climate research has well-defined goals (Mars Exploration Program Analysis Group 2018). Achieving these goals requires geologists and climate modelers to coordinate. Coordination is easier if results are expressed in terms of…
In a recent paper [1] Lineweaver and Davis performed a statistical analysis to claim that the rapidity of biogenesis on Earth indicates high probability of biogenesis on terrestrial- type planets. We argue that the rapid appearance of life…
It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case,…
Creating autonomous, self-supporting, self-replicating, sustainable systems is a great challenge. To some extent, understanding life means not only being able to create it from scratch, but also improving, supporting, saving it, or even…
With recent observations confirming exoplanets orbiting white dwarfs, there is growing interest in exploring and quantifying the habitability of temperate rocky planets around white dwarfs. In this work, the limits of the habitable zone of…
We address three questions regarding solar system planets. What determined their number? Why are their orbits nearly circular and coplanar? How long did they take to form? Runaway accretion in a disk of small bodies resulted in a tiny…
Ecological systems comprise an astonishing diversity of species that cooperate or compete with each other forming complex mutual dependencies. The minimum requirements to maintain a large species diversity on long time scales are in general…
Evolutionary complexity is here measured by the number of trials/evaluations needed for evolving a logical gate in a non-linear medium. Behavioural complexity of the gates evolved is characterised in terms of cellular automata behaviour. We…
We present an analytical proof assisted by computer calculations for the dynamical stability of the eight main planets and Pluto for the next 100,000 years. It means that the semi-major axes of the planets will not change significantly…
Mars is the Solar System's canonical small, rocky planet that transitioned from early geologic activity and surface liquid water to a cold and arid planet with a thin, cold, CO$_2$-dominated atmosphere. The evolution of Mars, in the context…
About 5-15% of stellar systems are at least triple. About 1% of systems with a primary of $\tgs 1 \Mscun$ are triple with a {\it longer} peri od that is less than 30y, and so may in principle be capable of Roche-lobe overflow in both the…
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…
At this point in time, there is very little empirical evidence on the likelihood of a space-faring species originating in the biosphere of a habitable world. However, there is a tension between the expectation that such a probability is…