kosmos: Extraterrestrial liquid water

Evidence: 100 • 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: 45 • authority: 72

The presence of water on the terrestrial planets of the Solar System (Mercury, Venus, Earth, Mars, and the closely related Earth's Moon) varies with each planetary body, with the exact origins remaining unclear. Additionally, the terrestrial dwarf planet Ceres is known to have water ice on its surface.

Evidence: 45 • authority: 72

The Earth is unique among known planets in having oceans of liquid water on its surface. It was long thought that Earth's water did not originate from the planet's region of the protoplanetary disk. Instead, it was hypothesized that water and other volatiles must have been delivered to Earth from the outer Solar System later in its history. Recent research, however, indicates that hydrogen inside the Earth played a role in the formation of the ocean. The two ideas are not mutually exclusive, as there is also evidence that water was delivered to Earth by impacts from icy planetesimals similar in composition to asteroids in the outer edges of the asteroid belt. Liquid water, necessary for all…

Evidence: 41 • authority: 90

Water in the Solar System. Abstract Over the past half century, numerous research space missions have been launched to explore various objects in the Solar System, primarily to find surface or subsurface water or water ice (in particular, to discover extraterrestrial oceans or their traces and to study their evolution in light of Earth’s hydrospheric history). This paper briefly reviews the subject with an emphasis on the terrestrial planets to find out why it is that, while liquid water oceans once formed and still exist on Earth, the surfaces of other planets turned into arid deserts. Also reviewed are issues related to the origin and observation of water ice in the outer part of the Sola…

Evidence: 40 • authority: 90

Hydrogen, Hydrocarbons, and Habitability Across the Solar System. The ingredients to make an environment habitable (e.g., liquid water, chemical disequilibria, and organic molecules) are found throughout the solar system. Liquid water has existed transiently on some bodies and persistently as oceans on others. Molecular hydrogen occurs in a plume on Saturn’s moon Enceladus. It can drive the reduction of CO2 to release energy. Methane has been observed in many places: from the dusty plains of Mars, to the great lakes of the Saturnian moon Titan, to the glacial wonderland that is Pluto. Organic molecules are common where volatile elements and reducing conditions prevail: these organic molecul…

Evidence: 40 • authority: 72

Vapor, water vapour, or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor is transparent, like most constituents of the atmosphere. Under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is less dense than most of the other constituents of air and triggers convection currents that can lead to clouds and fog. Being a component of Earth's hydrosphere and hydrologic cycle, it is particularly abundant in Earth's atmosphere, where it acts as a greenhouse gas and warmi…

Evidence: 40 • authority: 72

Extraterrestrial life, or alien life (colloquially aliens), is life that originates from another world rather than on Earth. No extraterrestrial life has yet been detected. Such life might range from simple forms such as microbes to intelligent beings, possibly bringing forth civilizations that might be far more, or far less, advanced than humans. The Drake equation speculates about the existence of sapient life elsewhere in the universe. The science of extraterrestrial life is known as astrobiology. Speculation about inhabited worlds beyond Earth dates back to antiquity. Early Christian writers, including Augustine, discussed ideas from thinkers like Democritus and Epicurus about countless…

Evidence: 34 • 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: 34 • authority: 90

Extraterrestrial Water. Research Article| January 01, 2005 Extraterrestrial Water Michael E. Zolensky Michael E. Zolensky 1Astromaterials Research and Exploration Science NASA Johnson Space Center, Houston, TX 77058 USA E-mail: michael.e.zolensky@nasa.gov Search for other works by this author on: GSW Google Scholar Elements (2005) 1 (1): 39–43. https://doi.org/10.2113/gselements.1.1.39 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Michael E. Zolensky; Extraterrestrial Water. Elements 2005;; 1 (1): 39–43. doi: https://doi.org/10.2113/gselements.1…

Evidence: 29 • authority: 92

Viruses in Extreme Marine Environments and Their Potential Existence in Extraterrestrial Environments.. Viruses are abundant and widespread in extreme marine environments, such as sea ice, hydrothermal vents, and ocean trenches. They occur at temperatures up to 122 °C and down to -30 °C and pressures exceeding 100 MPa. Their distribution in these environments is closely correlated with that of their extremophile hosts, which are mostly bacteria, archaea, and microeukaryotes. Viruses have been shown to be capable of long-term survival in conditions simulating interstellar conditions. However, for them to reproduce, they would still need a host. Many recent astro-biological investigations hav…

Evidence: 27 • authority: 80

Water Worlds in the Solar System: Exploring Prospects of Extraterrestrial Habitability & Life

Evidence: 27 • authority: 80

Wonder of the Solar System: Icy Geysers and Liquid Water on Enceladus. Source: Springer eBooks. Year: 2016