Linda T. Elkins-Tanton

• Ph.D. in geology and geophysics from MIT, 2002
• Managing Director at Arizona State University

One of the central questions to be addressed by the NASA Psyche mission is the composition and origin of the asteroid (16) Psyche. In preparation of the mission's planned arrival in 2029, in this work we explore how different internal structures may be expressed on (16) Psyche. We model the core size and shape that may exist at (16) Psyche given cu...

Magma ocean crystallization models that track fO2 evolution can reproduce the D/H ratios of both the Earth and Mars without the need for exogenous processes. Fractional crystallization leads to compositional evolution of the bulk oxide components. Recent work suggests that metal‐saturated magma oceans may contain near‐present‐day Fe³⁺ concentration...

Our understanding of solar system evolution is closely tied to interpretations of asteroid composition, particularly the M-class asteroids. These asteroids were initially thought to be the exposed cores of differentiated planetesimals, a hypothesis based on their spectral similarity to iron meteorites. However, recent astronomical observations have...

Our understanding of Solar System evolution is closely tied to interpretations of asteroid composition, particularly the M-class asteroids. These asteroids were initially thought to be the exposed cores of differentiated planetesimals, a hypothesis based on their spectral similarity to iron meteorites. However, recent astronomical observations have...

Plain Language Summary Asteroid (16) Psyche is the largest known metal‐rich asteroid and is a relic of the building blocks of the planets from the early solar system. We hypothesize that it is either an exposed metallic core of an asteroid or unmelted metal‐rich material. NASA's Psyche mission, launched in October 2023, aims to explore Psyche to un...

Magma ocean crystallization models that track fO2 evolution can reproduce the D/H ratios of both the Earth and Mars without the need for exogenous processes. Fractional crystallization leads to compositional evolution of the bulk oxide components. Metal-saturated magma oceans have long been thought to contain negligible ferric iron oxide (Fe3+O1.5)...

The NASA Psyche mission’s program to engage university undergraduates and the public in the mission is inspired by and built upon the extensive foundation of public engagement, educational outreach activities, and expertise of NASA and mission partner institutions. The program leverages the enthusiasm and contributions of undergraduates nationwide...

Primitive achondrites represent residual mantle material of planetesimals from which up to 20% partial melts were extracted. Melting experiments on chondritic compositions suggest that melts produced by <~20% partial melting are rich in silica and alkali elements. Such melts are highly viscous (>~10^3 Pa.s), and percolation models predict that they...

The objective of the NASA Psyche mission gravity science investigation is to map the mass distribution within asteroid (16) Psyche to elucidate interior structure and to resolve the question of whether this metal-rich asteroid represents a remnant metal core or whether it is a primordial body that never melted. Measurements of gravity will be obtai...

The solar nebula sustained a strong magnetic field that may have aided planetesimal accretion and imparted the chemical remanent magnetization (CRM) observed in some carbonaceous chondrite meteorites. The CRM thus provides a record of the magnetic field of the early Solar System at the time when carbonaceous chondrite parent bodies experienced aque...

The deuterium-to-hydrogen (D/H or ²H/¹H) ratio of Martian atmospheric water (∼6× standard mean ocean water, SMOW) is higher than that of known sources, requiring planetary enrichment. A recent measurement by NASA's Mars Science Laboratory rover Curiosity of Hesperian-era (>3 Ga) clays yields a D/H ratio ∼3×SMOW, demonstrating that most of the enric...

The deuterium-to-hydrogen (D/H or 2H/1H) ratio of Martian atmospheric water (~6x standard mean ocean water, SMOW) is higher than that of known sources, requiring planetary enrichment. A recent measurement by NASA's Mars Science Laboratory rover Curiosity of >3 Gyr clays yields a D/H ratio ~3x SMOW, demonstrating that most enrichment occurs early in...

NASA’s Discovery mission Psyche will soon be launched to visit the asteroid 16 Psyche. In this work, we model the surface temperatures of 16 Psyche. Our modeling is focused on capturing the diurnal and seasonal surface temperature variations caused by 16 Psyche’s large obliquity (95°) and moderately high eccentricity (0.134). Using a semianalytic f...

Plain Language Summary Radiation belts are regions in space filled with energetic charged particles trapped by a planetary magnetic field. To date, radiation belts were found around Earth, Jupiter, Saturn, Uranus, and Neptune. Understanding radiation belts is important because they can be hazardous to spacecraft. In addition, their emission, if det...

The asteroid (16) Psyche may be the metal-rich remnant of a differentiated planetesimal, or it may be a highly reduced, metal-rich asteroidal material that never differentiated. The NASA Psyche mission aims to determine Psyche’s provenance. Here we describe the possible solar system regions of origin for Psyche, prior to its likely implantation int...

This study explores the compositions and sizes of metallic cores that result from planetesimals forming from a range of chondritic bulk compositions. Our models examine the influence of starting bulk composition on core size and composition, how oxygen fugacity (fO2), temperature, pressure, and bulk composition affect sulfur partitioning between th...

The Main Belt Asteroid (16) Psyche is the target object of the NASA Discovery Mission Psyche. We observed the asteroid at ultraviolet (UV) wavelengths (170–310 nm) using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope during two separate observations. We report that the spectrum is very red in the UV, with a blue upturn short...

The Permian-Triassic extinction was the most severe in Earth history. The Siberian Traps eruptions are strongly implicated in the global atmospheric changes that likely drove the extinction. A sharp negative carbon isotope excursion coincides within geochronological uncertainty with the oldest dated rocks from the Norilsk section of the Siberian fl...

Large igneous province (LIP) eruptions have been linked in some cases to major perturbations of Earth's carbon cycle. However, few observations directly constrain the isotopic composition of carbon released by LIP magmas because carbon isotopes fractionate during degassing, which hampers understanding of the relative roles of mantle versus crustal...

Some years ago, the consensus was that asteroid (16) Psyche was almost entirely metal. New data on density, radar properties, and spectral signatures indicate that the asteroid is something perhaps even more enigmatic: a mixed metal and silicate world. Here we combine observations of Psyche with data from meteorites and models for planetesimal form...

The National Aeronautics and Space Administration (NASA) Psyche mission will visit the 226‐km diameter main belt asteroid (16) Psyche, our first opportunity to visit a metal‐rich object at close range. The unique and poorly understood nature of Psyche offers a challenge to the mission as we have little understanding of the surface morphology and co...

The influence of the hydrogen hydrodynamic upper atmosphere escape, driven by the solar soft X-ray and extreme ultraviolet radiation (XUV) flux, on an expected magma ocean outgassed steam atmosphere of early Venus is studied. By assuming that the young Sun was either a weak or moderate active young G star, we estimated the water loss from a hydroge...

Students don’t ask enough questions in classrooms, in person or online. Asking questions has been found to be a critical skill toward developing critical thinking abilities, improve learning performance, as well as career development. However, ‘how to ask productive questions’ as a key skill, is not well studied. Therefore, the present paper introd...

This poster presents the critical technology areas that must materialize for the development of a lunar settlement. It also details the major technology actors within each major technology category.

In January 2017, Psyche was one of two mission concepts selected by NASA for flight as part of the 14th Discovery mission competition. The project has been staffing up and maturing the spacecraft, instrument and mission system baseline designs on the path towards a 2022 launch. During much of 2018, the Project has been executing the lifecycle stage...

The tempo of Large Igneous Province emplacement is crucial to determining the environmental consequences of magmatism on the Earth. Based on detailed flow-by-flow paleomagnetic data from the most representative Permian-Triassic Siberian Traps lava stratigraphy of the northern Siberian platform, we present new constraints on the rate and duration of...

Gamma-­ray spectroscopy can be used to determine planetary elemental compositions, providing key information for understanding planet formation and evolution. Orbital gamma-­ray measurements have been collected previously from rocky or icy bodies such as Mercury, the Moon, (1) Ceres, (4) Vesta, (433) Eros, and Mars [1­6]. However, we have never vis...

Siberian Traps flood basalt magmatism coincided with the end-Permian mass extinction approximately 252 million years ago. Proposed links between magmatism and ecological catastrophe include global warming, global cooling, ozone depletion, and changes in ocean chemistry. However, the critical combinations of environmental changes responsible for glo...

Recent developments in planet formation theory and measurements of low D/H in deep mantle material support a solar nebula source for some of Earth's hydrogen. Here we present a new model for the origin of Earth's water that considers both chondritic water and nebular ingassing of hydrogen. The largest embryo that formed Earth likely had a magma oce...

Magma oceans are a common result of the high degree of heating that occurs during planet formation. It is thought that almost all of the large rocky bodies in the Solar System went through at least one magma ocean phase. In this paper, we review some of the ways in which magma ocean models for the Earth, Moon and Mars match present-day observations...

Magma oceans are a common result of the high degree of heating that occurs during planet formation. It is thought that almost all of the large rocky bodies in the Solar System went through at least one magma ocean phase. In this paper, we review some of the ways in which magma ocean models for the Earth, Moon, and Mars match present day observation...

The source of the ancient lunar magnetic field is an unsolved problem in the Moon's evolution. Theoretical work invoking a core dynamo has been unable to explain the magnitude of the observed field, falling instead one to two orders of magnitude below it. Since surface magnetic field strength is highly sensitive to the depth and size of the dynamo...

An analysis of meteoritic material from Mars provides an accurate timeline of the planet’s early history. The results have major implications for our understanding of the processes involved in rocky-planet formation. An analysis of meteoritic material from Mars provides an accurate timeline of the planet’s early history. The results have major impl...

The water content of magma oceans is widely accepted as a key factor that determines whether a terrestrial planet is habitable. Water ocean mass is determined as a result not only of water delivery and loss, but also of water partitioning among several reservoirs. Here we review our current understanding of water partitioning among the atmosphere,...

The water content of magma oceans is widely accepted as a key factor that determines whether a terrestrial planet is habitable. Water ocean mass is determined as a result not only of water delivery and loss, but also of water partitioning among several reservoirs. Here we review our current understanding of water partitioning among the atmosphere,...

The geophysics of extrasolar planets is a scientific topic often regarded as standing largely beyond the reach of near-term observations. This reality in no way diminishes the central role of geophysical phenomena in shaping planetary outcomes, from formation, to thermal and chemical evolution, to numerous issues of surface and near-surface habitab...

Highly volcanic exoplanets, which can be variously characterized as 'lava worlds', 'magma ocean worlds', or 'super-Ios' are high priority targets for investigation. The term 'lava world' may refer to any planet with extensive surface lava lakes, while the term 'magma ocean world' refers to planets with global or hemispherical magma oceans at their...

Anorthosites that comprise the bulk of the lunar crust are believed to have formed during solidification of a Lunar Magma Ocean (LMO) in which these rocks would have floated to the surface. This early flotation crust would have formed a thermal blanket over the remaining LMO, prolonging solidification. Geochronology of lunar anorthosites indicates...

Anorthosites that comprise the bulk of the lunar crust are believed to have formed during solidification of a Lunar Magma Ocean (LMO) in which these rocks would have floated to the surface. This early flotation crust would have formed a thermal blanket over the remaining LMO, prolonging solidification. Geochronology of lunar anorthosites indicates...

In January 2017, Psyche and a second mission concept were selected by NASA for flight as part of the 14th Discovery mission competition. Assigned for an initial launch date in 2023, the Psyche team was given direction shortly after selection to research the possibility for earlier opportunities. Ultimately, the team was able to identify a launch op...

The timeline of the lunar bombardment in the first Gy of the Solar System remains unclear. Some basin-forming impacts occurred 3.9-3.7Gy ago. Many other basins formed before, but their exact ages are not precisely known. There are two possible interpretations of the data: in the cataclysm scenario there was a surge in the impact rate approximately...

We create the first quantitative model for the early lunar atmosphere, coupled with a magma ocean crystallization model. Immediately after formation, the moon's surface was subject to a radiative environment that included contributions from the early Sun, a post-impact Earth that radiated like a mid-type M dwarf star, and a cooling global magma oce...

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers visc...

Processes governing the evolution of planetesimals are critical to understanding how rocky planets are formed, how water is delivered to them, the origin of planetary atmospheres, how cores and magnetic dynamos develop, and ultimately, which planets have the potential to be habitable. Theoretical advances and new data from asteroid and meteorite ob...

Processes governing the evolution of planetesimals are critical to understanding how rocky planets are formed, how water is delivered to them, the origin of planetary atmospheres, how cores and magnetic dynamos develop, and ultimately, which planets have the potential to be habitable. Theoretical advances and new data from asteroid and meteorite ob...

Processes governing the evolution of planetesimals are critical to understanding how rocky planets are formed, how water is delivered to them, the origin of planetary atmospheres, how cores and magnetic dynamos develop, and ultimately, which planets have the potential to be habitable. Theoretical advances and new data from asteroid and meteorite ob...

Processes governing the evolution of planetesimals are critical to understanding how rocky planets are formed, how water is delivered to them, the origin of planetary atmospheres, how cores and magnetic dynamos develop, and ultimately, which planets have the potential to be habitable. Theoretical advances and new data from asteroid and meteorite ob...

A working timeline for the history of ordinary chondrites includes chondrule formation as early as 0-2 Ma after our Solar System’s earliest forming solids (CAIs), followed by rapid accretion into undifferentiated planetesimals that were heated internally by ²⁶Al decay and cooled over a period of tens of millions of years. There remains conflict, ho...

Our neighborhood of planets was not created slowly, as scientists once thought, but in a speedy blur of high-energy crashes, destruction and rebuilding

Recent revisions to our understanding of the collisional history of the Hadean and early-Archean Earth indicate that large collisions may have been an important geophysical process. In this work we show that the early bombardment flux of large impactors (>100 km) facilitated the atmospheric release of greenhouse gases (particularly CO2) from Earth'...

Several new scenarios of the Moon-forming giant impact have been proposed to reconcile the giant impact theory with the recent recognition of the volatile and refractory isotopic similarities between Moon and Earth. Two scenarios leave the post-impact Earth spinning much faster than what is inferred from the present Earth-Moon system's angular mome...

With the advent of exoplanetary astronomy and the ongoing discovery of terrestrial-type planets around other stars, our own solar system becomes a key testing ground for ideas about what factors control planetary evolution. In particular, what allows a planet to be both within a potentially habitable zone and sustain habitability over long geologic...

We present a study on the influence of the upper atmosphere hydrodynamic escape of hydrogen, driven by the solar soft X-ray and extreme ultraviolet radiation (XUV), on an expected outgassed steam atmosphere of early Venus. By assuming that the young Sun was either a weak or moderately active young G star, we estimated the water loss from a hydrogen...

The origin of the Ethiopian-Yemeni Oligocene flood basalt province is widely interpreted as representing mafic volcanism associated with the Afar mantle plume head, with minor contributions from the lithospheric mantle. We reinterpret the geochemical compositions of primitive Oligocene basalts and picrites as requiring a far more significant contri...

Rocky planets are built through a series of highly energetic accretionary impacts. The accreting bodies are thought to carry small amounts of water to the growing planet, but it is debated whether the planet can retain this water through the accretionary process, or if water needs to be added largely after the planet is complete and cooled. Most of...

The Siberian Traps are one of the largest known continental flood basalt provinces and may be causally related to the end-Permian mass extinction. In some areas, a large fraction of the Siberian Traps volcanic sequence consists of mafic volcaniclastic rocks. Here, we synthesize paleomagnetic, petrographic, and field data to assess the likely origin...

Asteroid (16) Psyche is likely a metallic planetesimal core, stripped by hit-and-run impacts. It offers a unique window into core and dynamo formation.

Covering a key connection between geological processes and life on Earth, this multidisciplinary volume describes the effects of volcanism on the environment by combining present-day observations of volcanism and environmental changes with information from past eruptions preserved in the geologic record. The book discusses the origins, features and...

Covering a key connection between geological processes and life on Earth, this multidisciplinary volume describes the effects of volcanism on the environment by combining present-day observations of volcanism and environmental changes with information from past eruptions preserved in the geologic record. The book discusses the origins, features and...

Covering a key connection between geological processes and life on Earth, this multidisciplinary volume describes the effects of volcanism on the environment by combining present-day observations of volcanism and environmental changes with information from past eruptions preserved in the geologic record. The book discusses the origins, features and...

The physical processes active during the crystallization of a low-pressure, low-gravity planetesimal core are poorly understood but have implications for asteroidal magnetic fields and large-scale asteroidal structure. We consider a core with only a thin silicate shell, which could be analogous to some M-type asteroids including Psyche, and use a p...

Large igneous provinces are recognized from the Precambrian at 3.79 Ga (Ernst, 2013), and extend through well-preserved examples from the Mesozoic and Cenozoic (Ross et al., 2005; Bryan and Ferrari, 2013, and references therein). While originally inferred to consist of a layer-cake sequence of massive and laterally continuous effusive basaltic lava...

Even relatively small volcanic eruptions can have significant impacts on global climate. The eruption of El Chichón in 1982 involved only 0.38 km3 of magma (Varekamp et al., 1984); the eruption of Mount Pinatubo in 1993 involved 3-5 km3 of magma (Westrich and Gerlach, 1992). Both these eruptions produced statistically significant climate signals la...

There is little reason to believe that eruption of the Siberian Traps occurred gradually. On the contrary, trap emplacement likely occurred in the form of brief but voluminous volcanic pulses, as for example demonstrated for theDeccan Traps (Chenet et al., 2008, 2009) in India and for the Karoo Traps (Moulin et al., 2011, 2012) in South Africa. To...

The diversity of mineralogies and textures in the asteroidal meteorite collection promises a similarly diverse array of parent bodies and relatives as we continue exploring the asteroid belt. The presence of metamorphosed and igneous meteorites demonstrates that even some small bodies were heated significantly, permitting a variety of complexly int...

One possible mechanism to explain the observed variability of the short-lived and systems recorded in some early Earth rocks is crystal-liquid fractionation and overturn in an early magma ocean. This process could also potentially explain the deviation between the 142Nd isotopic composition of the accessible Earth and the chondritic average. To exa...

Over 500 quasi‐circular volcano‐tectonic features called coronae occur on Venus. They are believed to form via small‐scale mantle upwellings, lithospheric instability, or a combination thereof. Coronae and rifts commonly occur together, including many coronae that lie outside of the fracture zone. However, the genetic link between the two has remai...

Leading theories for the presence of plate tectonics on Earth typically appeal to the role of present day conditions in promoting rheological weakening of the lithosphere. However, it is unknown whether the conditions of the early Earth were favorable for plate tectonics, or any form of subduction, and thus how subduction begins is unclear. Using p...

The lack of contraction features on the Moon has been used to argue that the Moon underwent limited secular cooling, and thus had a relatively cool initial state. A cool early state in turn limits the depth of the lunar magma ocean. Recent GRAIL gravity measurements, however, suggest that dikes were emplaced in the lower crust, requiring global lun...

The history of the Hadean Earth (∼4.0-4.5 billion years ago) is poorly understood because few known rocks are older than ∼3.8 billion years old. The main constraints from this era come from ancient submillimetre zircon grains. Some of these zircons date back to ∼4.4 billion years ago when the Moon, and presumably the Earth, was being pummelled by a...

The Siberian Traps flood basalts transferred a large mass of volatiles from the Earth's mantle and crust to the atmosphere. The eruption of the large igneous province temporally overlapped with the end-Permian mass extinction. Constraints on the sources of Siberian Traps volatiles are critical for determining the overall volatile budget, the role o...

Observing the surface of Venus in the near-infrared from orbit or from an aerial platform will provide new insights into the mineralogy of Venus. In combination with a high-resolution radar mapper that provides accurate topographic data, this would allow global or regional mapping of the surface composition at a spatial scale of approximately 50km....

Planetesimals represent turning points in planetary formation, when the materials required for building planets are first incorporated into bodies with radii from tens to hundreds of kilometers or larger, and are sometimes differentiated into metallic cores and silicate mantles. These early celestial bodies are the accretionary step between the dus...

High abundances of short-lived radiogenic isotopes in the early solar system led to interior melting and differentiation on many of the first planetesimals. Petrologic, isotopic, and paleomagnetic evidence suggests that some differentiated planetesimals retained primitive chondritic material. The preservation of a cold chondritic lid depends on whe...

[1] Energy of accretion in terrestrial planets is expected to create liquid silicate magma oceans. Their solidification processes create silicate differentiation and set the initial mantle structure for the planet. Solidification may result in a compositionally unstable density profile, leading to cumulate Rayleigh-Taylor overturn if a sluggish rat...

We propose to visit an iron core by sending a mission to (16) Psyche, by far the largest exposed iron metal body in the solar system.

Venus Express VIRTIS heritage and new laboratory emissivity data provide a baseline for future Venus mission instrument concepts as the Venus Emissivity Mapper.

The HED meteorites are best modeled by melt extraction from a mush into shallow magma chambers, a model consistent with inefficient crystal settling in an interior magma ocean.