geologia: Plate tectonics

Evidence: 64 • authority: 92

Dissecting the puzzle of tectonic lid regimes in terrestrial planets.. The surface tectonic style of rocky planets controls interior evolution, geologic activity, dynamo action, atmospheric composition, and thus, habitability. In the solar system, Earth is unique in exhibiting plate tectonics, but it also displays a protracted history of diverse tectonic regimes. To understand the dynamics of the coupled plate-mantle system, here we explore 2D hemispheric-scale thermochemical mantle convection models with self-consistent magmatism that reach the statistical steady state. By statistical analysis of model predictions, we quantitatively distinguish between six tectonic regimes, including the m…

Evidence: 58 • authority: 92

Rocky Planets as Heat Engines.. Rocky planets act as heat engines, using internal heat to drive mantle convection, tectonic activity, crustal evolution and magnetic field generation. This ultimately shapes the surface environment and long-term habitability. This article reviews the physical and chemical processes governing the interior dynamics of rocky planets in the Solar System and beyond, emphasizing how variations in heat sources, material properties, internal structure, and boundary conditions (e.g., surface temperature and stellar flux) lead to diverse evolutionary pathways. Planetary heat arises from primordial accretion, core formation, radiogenic decay, tidal dissipation, and impa…

Evidence: 64 • authority: 72

Plate tectonics (from Latin tectonicus, from Ancient Greek τεκτονικός (tektonikós) 'pertaining to building') is the scientific theory that Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of continental drift, an idea developed during the first decades of the 20th century. Plate tectonics came to be accepted by geoscientists after seafloor spreading was validated in the mid- to late 1960s. The processes that result in plates and shape Earth's crust are called tectonics. Earth's lithosphere, the rigid outer shell of the planet including the crust and upper mantle, is fractured into seve…

Evidence: 58 • authority: 72

Tectonics (from Ancient Greek τεκτονικός tektonikós 'pertaining to building' via Latin tectonicus) are the processes that result in the structure and properties of Earth's crust and its evolution through time. The field of planetary tectonics extends the concept to other planets and moons. These processes include those of mountain-building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute Earth's outer shell interact with each other. Principles of tectonics also provide a framework for understanding the earthquake and volcanic belts that directly affect much of the global population. Tectonic s…

Evidence: 52 • 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: 47 • authority: 92

Waned mantle upwelling contributes to a heavily deformed northern smooth plains on Mercury.. Recent advancements in mapping and interpretation have revealed both numerous contractional landforms and evidence that tectonic activity has persisted into geologically recent times in Mercury's northern smooth plains (NSP). To investigate the mechanisms behind these observations, we conduct a comprehensive assessment of contractional strain across the NSP. Our analysis reveals that (1) the NSP exhibits higher strain than other terranes on Mercury, and (2) the surface deformation pattern is spatially correlated with the Northern Rise (NR) at the center of the NSP, suggesting an additional driving f…

Evidence: 47 • authority: 72

A volcano is a vent or fissure in the crust of a planetary-mass object that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually nonexplosive whereas those resulting from convergent tectonic activity cause v…

Evidence: 47 • 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…

Evidence: 41 • authority: 88

Prospects for Life on Other Planets. This book describes a hypothetical process in which populations of protocells can spontaneously assemble and begin to grow and proliferate by energy- dependent polymerization. This might seem to be just an academic question pursued by a few dozen researchers as a matter of curiosity, but in the past three decades advances in engineering have reached a point where both NASA and the European Space Agency (ESA) routinely send spacecraft to other planetary objects in our solar system. A major question being pursued is whether life has emerged elsewhere than on Earth. The limited funds available to support such missions require decisions to be made about targ…

Evidence: 41 • authority: 88

Mercury's Tectonic and Geodynamic History: 1. Contractional Tectonic Landform Analysis and Tectonic Strain Using Machine Learning. Abstract Mercury's tectonic record is dominated by shortening landforms, including lobate scarps, high‐relief ridges and wrinkle ridges. Previous analyses of these structures have used displacement–length ratios to constrain the planet's global contraction to a range of either no more than 2 km or up to 7 km. This important discrepancy has strong implications for our understanding of Mercury's geodynamic history and results from different interpretations of the tectonic record. Studies in favor of less contraction do not include wrinkle ridges and other small‐sc…

Evidence: 41 • 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: 35 • authority: 88

Long‐Lived and Continual Volcanic Eruptions, Tectonic Activity, Pit Chains Formation, and Boulder Avalanches in Northern Tharsis Region: Implications for Late Amazonian Geodynamics and Seismo‐Tectonic Processes on Mars. Abstract Tharsis is the largest volcanic province on Mars. It consists of a few large shield volcanoes, one of which is Alba Mons (AM), located in northern Tharsis, with the Ceraunius Fossae (CF) graben system to the south of it. Previous workers argued in favor of episodic building of Tharsis volcanoes. In contrast, we show that volcanism in the AM and CF regions occurred continually, at least in the last few hundred million years, based on ages of >1,000 stratigraphically…