lotnictwo: Solar System

Evidence: 86 • authority: 72

Extraterrestrial liquid water is water in its liquid state that naturally occurs outside Earth. It is a subject of wide interest because it is recognized as one of the key prerequisites for life as we know it and is thus surmised to be essential for extraterrestrial life. Although many celestial bodies in the Solar System have a hydrosphere, Earth is the only celestial body known to have stable bodies of liquid water on its surface, with oceanic water covering 71% of its surface, which is essential to life on Earth. The presence of liquid water is maintained by Earth's atmospheric pressure and stable orbit in the Sun's circumstellar habitable zone; however, the origin of Earth's water remai…

Evidence: 76 • authority: 88

Atmospheric escape from rocky M-dwarf planets orbiting within the habitable zone. <p>In the last two decades, the field of exoplanets has witnessed a tremendous creative surge. Research in exoplanets now encompasses a wide range of fields ranging from astrophysics to heliophysics and climate science. One of the primary objectives of studying exoplanets is to determine the criteria for habitability, and whether certain exoplanets meet these requirements. The classical definition of the Habitable Zone (HZ) is the region around a star where liquid water can exist on the planetary surface given sufficient atmospheric pressure. However, this definition largely ignores the impact of the stellar w…

Evidence: 73 • authority: 72

In astronomy and astrobiology, the habitable zone (HZ), also known as the circumstellar habitable zone (CHZ), or as the Goldilocks zone, is the range of orbits around a star within which a planetary surface could potentially support liquid water. Liquid water is considered by many scientists as necessary for a planet to be habitable. The range depends upon the brightness of the star interacting with a planet's atmosphere. At the inner edge the star's light, trapped by greenhouse gases in a planet's atmosphere, boils off the planet's water. At the outer edge light from the star is insufficient even with help from atmospheric gas and the planet's water freezes. Many other factors are added in…

Evidence: 61 • authority: 72

The habitability of natural satellites is the potential of moons to provide habitats for life. Natural satellites are expected to outnumber planets by a large margin and the study of their habitability is therefore important to astrobiology and the search for extraterrestrial life. Planetary mass, atmosphere, and geology are all important factors but there are significant environmental variables specific to moons. All planetary mass moons of the Solar System are tidally locked, the most significant difference in comparison to the planetary habitability of bodies that have "cleared their neighbourhood." They also tend to have more surface area relative to volume, thus dissipating heat and at…

Evidence: 61 • authority: 92

Euhabitability: A New Term to Aid in the Search for Life in Addition to the Habitable Zone Framework.. The search for life on exoplanets is difficult due to observational limitations stemming from vast separating distances. The Habitable Zone (HZ) is a simplifying framework for identifying exoplanets that may be suitable for life, given our observational limitations. The HZ framework is built on many simplifying assumptions and only attempts to bound the circumstellar regions where surface oceans are not precluded. In other words, HZ exoplanets are where surface oceans are possible, not necessarily where life is possible. Water is essential for life as we know it, however, life requires add…

Evidence: 54 • authority: 92

Flare-driven habitability: Expanding life's potential around low-mass stars.. The traditional definition of the circumstellar habitable zone (HZ) focuses on liquid water, but neglects the crucial role of ultraviolet (UV) radiation in prebiotic chemistry. Low-mass stars typically emit insufficient UV radiation for photochemistry throughout the liquid water HZs (LW-HZs) during quiescent states. However, frequent flares can provide substantial UV fluxes, potentially fostering habitable conditions. We refine the concept of a UV radiation HZ (UV-HZ) by incorporating a temperature-dependent model for RNA precursor synthesis. Furthermore, we explore a parameterized spectral energy distribution mod…

Evidence: 54 • authority: 72

The following list includes potentially habitable exoplanets. It is mostly based on estimates of habitability by the Habitable Worlds Catalog (HWC), and data from the NASA Exoplanet Archive. The HWC is maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. Surface planetary habitability is thought to require an orbit at the right distance from the host star for liquid surface water to be present, in addition to various geophysical and geodynamical aspects, atmospheric density, radiation type and intensity, and the host star's plasma environment.

Evidence: 48 • authority: 92

The chemistry of habitable oceans in the Solar system.. Liquid water exists on the Earth and several other planetary bodies in our solar system. The chemical character of these aqueous reservoirs is central to evaluating their habitability. Here, we synthesize the chemical features of water reservoirs and their biological implications on the modern Earth. We then outline constraints on the evolutionary history of Earth's ocean chemistry and discuss its interplay with the biosphere. Furthermore, we examine the inferred chemical environments of water bodies on early Mars, dwarf planet Ceres, Jupiter's moon Europa and Saturn's moons Enceladus and Titan. We conclude by outlining priority questi…

Evidence: 48 • authority: 92

What the Solar System Can Teach Us About Rocky Exoplanets.. The number of rocky extrasolar planets being discovered continues to increase, but so too does the apparent diversity of such worlds. As we work to understand the likely bulk properties and thermal, geological, and climatological attributes we might expect of rocky exoplanets, we can look to the Solar System for guidance. Here, we review the interior, surface, and atmospheric characteristics of modern Earth, and discuss how our homeworld has changed through Solar System history. We then visit in turn Venus, Mars, Mercury and Earth's Moon, and Io, noting how these terrestrial planets are alike, how they are different, and how they h…

Evidence: 42 • authority: 88

Search for Earth-like planets in the habitable zone of M-dwarfs. Recherche de planètes habitables autour de naines M Depuis la première détection d'une planète extrasolaire autour d'une étoile de type solaire par Mayor et Queloz (1995), plus de 1500 planètes ont été découverts. Actuellement il existe un énorme intérêt à découvrir et caractériser des planètes semblables à la Terre, en particulier celles situées dans la zone habitable de leur étoile hôte (définie comme la distance à l'étoile hôte où la température de la planète permet l'existence d'eau liquide à la surface). La détection de planètes de type terrestre, et la recherche de biomarqueurs dans leurs atmosphères sont parmi les princ…

Evidence: 36 • authority: 92

Evolution and Observable Properties of Rocky Planet Atmospheres.. The atmospheric composition of rocky exoplanets offers an important tool for constraining the properties of the interior of this type of planet, beyond what is possible from measurements of their mass and radius alone. However, the interpretation of these observations requires an understanding of the complex interplay of a larger number of coupled planetary and atmospheric processes. This review provides an overview of the current state of knowledge regarding rocky exoplanet atmospheres, beginning with their formation and escape mechanisms. We specifically highlight the importance of long-term interaction between the atmosphe…

Evidence: 36 • authority: 72

An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detected in 1988, was confirmed in 2003. In 2016, it was recognized that the first possible evidence of an exoplanet had been noted in 1917, a precovery. As of 8 October 2026, there are 6,445 confirmed exoplanets in 4,834 planetary systems, with 1,070 systems having more than one planet. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias fa…