Michael J Malaska

Michael J Malaska
California Institute of Technology | CIT · Jet Propulsion Laboratory

PhD

About

162
Publications
22,242
Reads
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1,726
Citations
Citations since 2016
92 Research Items
1443 Citations
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Introduction
My research uses laboratory experimentation, planetary mapping, and field research to understand the geological and chemical processes occurring on the surface of Saturn's moon Titan.
Additional affiliations
July 2015 - present
Jet Propulsion Laboratory / California Institute of Technology
Position
  • Researcher
October 2012 - present
California Institute of Technology
Position
  • Senior NASA Postdoctoral Fellow

Publications

Publications (162)
Article
Full-text available
Nearly half a century ago, two papers postulated the likelihood of lunar lava tube caves using mathematical models. Today, armed with an array of orbiting and fly-by satellites and survey instrumentation, we have now acquired cave data across our solar system—including the identification of potential cave entrances on the Moon, Mars, and at least n...
Article
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We provide the first solar system wide compendium of speleogenic processes and products. An examination of 15 solar system bodies revealed that six cave‐forming processes occur beyond Earth including volcanic (cryo and magmatic), fracturing (tectonic and impact melt), dissolution, sublimation, suffusion, and landslides. Although no caves (i.e., con...
Article
Full-text available
We propose that cycling hydrocarbon rains on Saturn's moon Titan are likely to create subsurface conduits through dissolution geology of the extensive organic and largely‐soluble substrate. In this work we inventory different terrains and locations on Titan that could host potential subsurface access points or caves. Using Cassini data, we identifi...
Article
Full-text available
Titan is a sedimentary world, with lakes, rivers, canyons, fans, dissected plateaux, and sand dunes. Sediments on Saturn's moon are thought to largely consist of mechanically weak organic grains, prone to rapid abrasion into dust. Yet, Titan's equatorial dunes have likely been active for 10s-100s kyr. Sustaining Titan's dunes over geologic timescal...
Article
Full-text available
Cassini revealed that Saturn's Moon Enceladus hosts a subsurface ocean that meets the accepted criteria for habitability with bio-essential elements and compounds, liquid water, and energy sources available in the environment. Whether these conditions are sufficiently abundant and collocated to support life remains unknown and cannot be determined...
Article
Full-text available
In response to ESA’s “Voyage 2050” announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn’s largest moon Titan. Titan, a “world with two oceans”, is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. T...
Article
Earth’s ocean comprises 99% of the habitable volume of our planet and contains the largest biomass and species diversity in the known universe. Perhaps unsurprisingly, recent advances in the search for life elsewhere in our solar system have increasingly pointed to potentially viable niches for life on other dynamic ocean worlds such as Titan, Euro...
Article
Mountain formation and evolution on Titan is poorly understood, due in part to a lack of high-resolution topographic data. By applying advanced processing techniques, we are able to increase the along-track spatial resolution of the Cassini RADAR altimeter by up to a factor of ten, enabling more detailed analysis. A survey of mountainous and hummoc...
Preprint
Full-text available
In response to ESA Voyage 2050 announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn largest moon Titan. Titan, a "world with two oceans", is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan i...
Article
Full-text available
The Arctic cryosphere is collapsing, posing overlapping environmental risks. In particular, thawing permafrost threatens to release biological, chemical and radioactive materials that have been sequestered for tens to hundreds of thousands of years. As these constituents re-enter the environment, they have the potential to disrupt ecosystem functio...
Article
Full-text available
Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integration...
Preprint
Full-text available
Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integration...
Article
Full-text available
Cassini Synthetic Aperture Radar (SAR) images of Titan’s surface revealed river networks strikingly similar to those on Earth. However, Cassini SAR has low spatial resolution and image quality compared to data used to map channels on Earth, so traditional methods for characterizing river networks might not yield accurate results on Titan. We mapped...
Article
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Titan is unique in the solar system: it is an ocean world, an icy world, an organic world, and has a dense atmosphere. It is a geologically active world as well, with ongoing exogenic processes, such as rainfall, sediment transportation and deposition, erosion, and possible endogenic processes, such as tectonism and cryovolcanism. This combination...
Article
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Enceladus is unique as an astrobiology target in that it hosts an active plume sourced directly from its habitable subsurface ocean. Ice particles from the plume contain geochemical constituents that are diagnostic of the ocean conditions, and may hold traces of life and/or biosignatures, if they exist. Up to 93% of the plume particles fall back on...
Article
Full-text available
Thanks to the Cassini–Huygens mission, Titan, the pale orange dot of Pioneer and Voyager encounters, has been revealed to be a dynamic, hydrologically shaped, organic-rich ocean world offering unparalleled opportunities to explore prebiotic chemistry. And while Cassini–Huygens revolutionized our understanding of each of the three “layers” of Titan—...
Article
We mapped in detail Titan's South Belet region which spans from longitude 60°E to 120°E and from latitude 60°S to 0°, encompassing both equatorial and southern mid-latitude regions. We used Cassini RADAR in its Synthetic Aperture Radar (SAR) mode data as our basemap, which covers 31.8% of the region, supplemented with data from the RADAR's radiomet...
Article
Full-text available
The Enceladus plume is a target of astrobiological interest in planetary science since it may carry signs of extraterrestrial life entrapped in ice grains formed from the subsurface ocean of this moon of Saturn. Fly-by mission concepts have been proposed to perform close investigations of the plume, including detailed in situ measurements of chemic...
Article
Full-text available
Enceladus’s long-lived plume of ice grains and water vapor makes accessing oceanic material readily achievable from orbit (around Saturn or Enceladus) and from the moon’s surface. In preparation for the National Academies of Sciences, Engineering and Medicine 2023–2032 Planetary Science and Astrobiology Decadal Survey, we investigated four architec...
Article
The atomic-scale fragmentation processes involved in molecules undergoing hypervelocity impacts (HVIs; defined as >3 km/s) are challenging to investigate via experiments and still not well understood. This is particularly relevant for the consistency of biosignals from small-molecular-weight neutral organic molecules obtained during solar system ro...
Article
Full-text available
The Science Case for a Titan Flagship-class Orbiter with Probes White paper #325 submitted to the Planetary Science and Astrobiology Decadal Survey 2023-2032. Topics: giant planets systems; ocean worlds; other: Mission Studies by Conor Nixon, James Abshire, Andrew Ashton, Jason W. Barnes, Nathalie Carrasco, Mathieu Choukroun, Athena Coustenis, Lo...
Article
Full-text available
Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integrati...
Article
Full-text available
As one of two planetary objects (other than Earth) that have solid surfaces, thick atmospheres, and astrobiological significance, Titan, like Mars, merits ongoing study with multiple spacecraft. We propose that a Titan orbiter dedicated to geophysics, geology, and atmospheric science be added to the New Frontiers menu for the coming decade.
Article
From orbit, the visibility of Titan’s surface is limited to a handful of narrow spectral windows in the near-infrared (near-IR), primarily from the absorption of methane gas. This has limited the ability to identify specific compounds on the surface—to date Titan’s bulk surface composition remains unknown. Further, understanding of the surface comp...
Preprint
Full-text available
Thanks to the Cassini-Huygens mission, Titan, the pale orange dot of Pioneer and Voyager encounters has been revealed to be a dynamic, hydrologically-shaped, organic-rich ocean world offering unparalleled opportunities to explore prebiotic chemistry. And while Cassini-Huygens revolutionized our understanding of each of the three layers of Titan--th...
Article
Full-text available
As one of two planetary objects (other than Earth) that have solid surfaces,thick atmospheres, and astrobiological significance, Titan, like Mars, merits ongoing studywith multiple spacecraft. We propose that a Titan orbiter dedicated to geophysics, geology,and atmospheric science be added to the New Frontiers menu for the coming decade.
Preprint
From orbit, the visibility of Titan's surface is limited to a handful of narrow spectral windows in the near-infrared (near-IR), primarily from the absorption of methane gas. This has limited the ability to identify specific compounds on the surface -- to date Titan's bulk surface composition remains unknown. Further, understanding of the surface c...
Article
Acetylene and ammonia are known to form a stable orthorhombic co-crystal under the surface conditions of Saturn's moon Titan (1.5 bar = 150 kPa, 94 K). Such a material represents a potential new class of organic minerals that could play an important role in Titan's geology. In this work, the thermal expansion of this co-crystalline system has been...
Preprint
Full-text available
We outline a flagship-class mission concept focused on studying Titan as a global system, with particular emphasis on the polar regions. Investigating Titan from the unique standpoint of a polar orbit would enable comprehensive global maps to uncover the physics and chemistry of the atmosphere, and the topography and geophysical environment of the...
Article
We investigate the spectral behavior of nine Titan impact craters in order to constrain their composition. Past studies that have examined the chemical composition of impact craters on Titan have either used qualitative comparisons between craters or combined all craters into a single unit, rather than separating them by geographic location and/or...
Article
Titan, the largest satellite of Saturn, possesses a complex photochemical cycle producing a broad inventory of organic molecules in its thick atmosphere and on its surface. Two of the most common molecules in this inventory include acetylene (C2H2) and acetonitrile (CH3CN). We have previously demonstrated that certain organic molecules (such as ben...
Article
Full-text available
We used a deep-ultraviolet fluorescence mapping spectrometer, coupled to a drill system, to scan from the surface to 105 m depth into the Greenland ice sheet. The scan included firn and glacial ice and demonstrated that the instrument is able to determine small (mm) and large (cm) scale regions of organic matter concentration and discriminate spect...
Preprint
Full-text available
Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integration...
Article
The inelastic scattering dynamics of the isobaric molecules, naphthalene (C10H8) and 2-octanone (C8H16O), on highly oriented pyrolytic graphite (HOPG) have been investigated as part of a broader effort to inform the inlet design of a mass spectrometer for the analysis of atmospheric gases during a flyby mission through the atmosphere of a planet or...
Article
Full-text available
Titan has an active methane-based hydrologic cycle¹ that has shaped a complex geologic landscape², making its surface one of most geologically diverse in the Solar System. Despite the differences in materials, temperatures and gravity fields between Earth and Titan, many of their surface features are similar and can be interpreted as products of th...
Conference Paper
Titan, the largest moon of Saturn, contains a vast inventory of org. mols. on the surface of a water-ice-dominated ocean world, making it a prebiotic chem. lab. on a planetary scale. Many of the org. mols. on Titan's surface appear to assoc. in a manner akin to minerals on Earth, forming mol. solids, co-crystals, and hydrates. These 'mol. minerals'...
Conference Paper
The Cassini-Huygens mission has revealed a wide variety of Earth-like landforms on Titan's surface: plains, mountains, dunes, lakes, seas and rivers. Titan's surface appears to be constructed from org. mols., rather than rocks and minerals that make up Earth's surface. At a surface temp. of ~92 K, the non-covalent interactions are sufficiently stro...
Conference Paper
The Saturnian moon Enceladus is thought to be one of the most ideal places to search for extraterrestrial, aq.-based life. Enceladus has a global, subsurface ocean that is sandwiched between an outer, icy shell and the moon's rocky core. Fractures in the ice shell at the southern pole of Enceladus give rise to the now-famous plume, which expresses...
Article
The Cassini/Huygens mission revealed a terrain type on Saturn's moon Titan of dissected, elevated plateaux with a high density of valleys named labyrinth terrain. We define four subtypes of labyrinth terrains: valleyed, polygonal, finely-dissected, and the possible outlier Kronin Labyrinth. We mapped the locations of all labyrinths imaged by Cassin...
Conference Paper
Full-text available
Titan's dense atmosphere, low gravity, and high winds at high altitudes create descent times of >90 minutes with standard entry/descent/landing (EDL) architectures and result in large unguided landing ellipses, with 99% values of ⇠110x110 km and 149x72 km in recent Titan lander proposals. Enabling precision landing on Titan could increase science r...
Article
Titan hosts a complex chemical engine producing a rich inventory of organic molecules in its thick atmosphere and on its surface. Some of these organics may be deposited in the liquid hydrocarbon lakes in the polar regions, and form evaporite features when the lakes dry out as part of Titan’s methane/ethane cycle that is analogous to Earth’s hydrol...
Conference Paper
Full-text available
Precision landing on planetary bodies uses terrain relative navigation (TRN) to estimate position during descent, by performing real-time, onboard registration of descent imagery to maps of the terrain created from prior orbital reconnaissance [1]. This is used to guide divert maneuvers to land close to desired targets or to avoid landing hazards t...
Article
Full-text available
We perform a systematic survey of Titan's sharp‐edged depressions (SEDs) using a combination of Cassini synthetic aperture radar images and delay‐Doppler processed altimetry. We identify a characteristic bright‐dark pattern around 172 SEDs that correlates with elevated features only resolved with the highest resolution topographic data. We find tha...
Article
Some of Titan's small northern hemisphere lakes show raised rampart features (which are distinct from raised rims), and appear as SAR-bright mound-like annuli extending away from the lake for up to tens of kilometers from the shoreline. We investigate the infrared and microwave characteristics of these features using Cassini Visual and Infrared Map...
Article
Full-text available
Titan was a mostly unknown world prior to the Cassini spacecraft’s arrival in July 2004. We review the major scientific advances made by Cassini’s Titan Radar Mapper (RADAR) during 13 years of Cassini’s exploration of Saturn and its moons. RADAR measurements revealed Titan’s surface geology, observed lakes and seas of mostly liquid methane in the p...
Article
Terrestrial icy environments have been found to preserve organic material and contain habitable niches for microbial life. The cryosphere of other planetary bodies may therefore also serve as an accessible location to search for signs of life. The Wireline Analysis Tool for the Subsurface Observation of Northern ice sheets (WATSON) is a compact dee...
Article
Full-text available
The surface of Mars has been well mapped and characterized, yet the subsurface — the most likely place to find signs of extant or extinct life and a repository of useful resources for human exploration — remains unexplored. In the near future this is set to change.