Category: 7. Science

  • Bioplastics for Life Beyond Earth

    Key takeaways

    • SEAS researchers grew green algae inside shelters that recreated pressure conditions on Mars.
    • The shelters were made from bioplastics derived from algae.
    • The experiments demonstrate the possibility of closed-loop, sustainable habitats in space.

    If humans are ever going to live beyond Earth, they’ll need to construct habitats. But transporting enough industrial material to create livable spaces would be incredibly challenging and expensive. Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) think there’s a better way, through biology. 

    An international team of researchers led by Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering and Professor of Earth and Planetary Sciences, have demonstrated that they can grow green algae inside shelters made out of bioplastics in Mars-like conditions. The experiments are a first step toward designing sustainable habitats in space that won’t require bringing materials from Earth.

    “If you have a habitat that is composed of bioplastic, and it grows algae within it, that algae could produce more bioplastic,” explained Wordsworth. “So you start to have a closed-loop system that can sustain itself and even grow through time.”

    The research is published in Science Advances.

    Growing algae in Mars-like conditions

    In lab experiments that recreated the thin atmosphere of Mars, Wordsworth’s team grew a common type of green algae called Dunaliella tertiolecta. The algae thrived inside a 3D-printed growth chamber made from a bioplastic called polylactic acid, which was able to block UV radiation while transmitting enough light to allow the algae to photosynthesize.

    The algae was kept under a Mars-like 600 Pascals of atmospheric pressure – over 100 times lower than Earth’s — and in a carbon dioxide-rich environment, as opposed to mostly nitrogen and oxygen like on Earth. Liquid water cannot exist at such low pressures, but the bioplastic chamber created a pressure gradient that stabilized water within it. The experiments point to bioplastics as potentially key to creating renewable systems for maintaining life in a lifeless environment.

    The concept the researchers demonstrated is closer to how organisms grow naturally on Earth, and it contrasts with an industrial approach using materials that are costly to manufacture and recycle.

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  • Ancient Life Locked Arsenic Away To Survive Environmental Changes

    Ancient Life Locked Arsenic Away To Survive Environmental Changes

    A 3D image obtained by X-ray microtomography of a macroscopic multicellular organism dated to 2.1 billion years ago (Francevillian Basin, Gabon). Scale bar = 1 cm. Credit Arnaud Mazurier and Abderrazak El Albani.

    Earth’s earliest life forms developed ways to survive the harmful effects of arsenic to cope with dramatic changes in their environment, a new study suggests.

    The researchers found the complex life forms, called eukaryotes, stored arsenic inside special compartments within their cells, a strategy that helped neutralise the toxic poison.

    Using advanced X-ray technology, the international team was able to detect and map arsenic within 2.1-billion-year-old fossils from the Francevillian Basin in Gabon.

    The arsenic found in the fossils was not due to later contamination but part of a biological response to environmental stress, according to the team.

    a Lobate fossil with imprint showing dispersed pyrite grains at the radial fabrics (RF) and coagulated pyrite towards the dome (D) (b). c Elongate fossil (E) in a matrix (M) with imprint surrounded by bacterial mat33 showing mainly coagulated pyrite crystals (d). e Tubular fossil (T) having an ovoid diameter filled with coagulated pyrite in a matrix (M) (f). g Pyritized abiotic concretion (C) found in the same location and containing massive pyrite (h). The diameter of the coin in (g) is 3.6 cm. Scanning electron microscope is used in back-scattered electron mode in b, d, f and h. It shows pyrite grains filling the specimens in a vertical transect — Nature Communications.

    This is revealed by distinct patterns formed from the arsenic preservation process in the fossils when compared to structures left by non-living mineral structures; it is further evidence the fossils were once complex living organisms with more advanced cells, they argue.

    Their study, published in Nature Communications, reshapes current understandings of how early life faced environmental challenges, highlighting the critical role adaptation played in the evolution of life.

    “The ability to cope with arsenic was not something eukaryotes developed randomly,” said Dr Ernest Chi Fru, one of the paper’s co-authors and Reader at Cardiff University’s School of Earth and Environmental Sciences.

    “It coincided with a period of significant environmental change, when oxygen levels in the Earth’s atmosphere first rose. This increase in oxygen also led to a rise in arsenate, a particularly toxic form of arsenic which competes with phosphate, a vital nutrient for all life, making Earth’s oceans a dangerous place.”

    a Oxidized As—arsenate or As5+ (red dots) is released into the ocean by the chemical and oxidative weathering of the continental crust. b During life, As enters the cell, and is detoxified first by reduction to As3+ (c) then extruded by cell membrane transporters or sequestered in intracellular compartments (d). e After death and burial, As is released from intracellular bodies into a localized reduced environment rich in iron (purple dots) where sulfate (green dots) is reduced to sulfides (yellow dots). f Pyrite is formed by microbial sulfate reduction with As acting as a catalyzer of pyrite nucleation. g Arsenic is rapidly consumed in low environmental concentrations. h Pyrite growth led to As depletion away from the core — Nature Communications.

    The study builds on the team’s previous work on the 2.1-billion-year-old Francevillian biota, which they argue appeared after a local underwater volcanic event brought a sudden surge of nutrients into a small, enclosed sea.

    This nutrient boost helped these early life forms thrive locally, according to the team led by Université de Poitiers and Cardiff University.

    Dr Chi Fru added: “We looked at the evolution of arsenic in the Francevillian basin’s seawater before and after the fossils. It was actually quite low in arsenic concentration at the time when these primitive eukaryotes evolved, leading us to think they should have lived there quite happily.

    “However, the surprisingly high levels of arsenic stored in their bodies, revealed in our analysis, suggest that they were extremely sensitive to even low levels of arsenic in seawater.”

    These organisms later became extinct when volcanic activity returned to the area, and oxygen levels in the seawater dropped, according to the team.

    They say their disappearance suggests the ability of complex life to protect itself from toxic substances like arsenic, by safely storing it inside cells, may have evolved more than once in Earth’s history.

    “All living things have ways to protect themselves from arsenic, which is toxic to life,” Dr Chi Fru said.

    “In the ocean, tiny plankton near the surface — the same ones that make about half the oxygen in the air we breathe — are always working to get rid of arsenic from their bodies. They can’t avoid it because arsenic is naturally in the water, and their cells can’t easily tell the difference between arsenate and phosphate, a nutrient they actually need. This was true even in ancient times, just like it is today.

    “We know these ancient organisms went extinct, so the way modern life handles arsenic didn’t come directly from them.”

    The paper, ‘A battle against arsenic toxicity by Earth’s earliest complex life forms’, is published in Nature Communications. (open access)

    Astrobiology

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  • The NEID Earth Twin Survey. III. Survey Performance After Three Years on Sky

    The NEID Earth Twin Survey. III. Survey Performance After Three Years on Sky

    Time series of relative FWHM measurements for all NETS stars with multiple nights of data collected prior to August 2021. We observe a sharp decrease in FWHM in August 2021 for all Solar-type stars, and we interpret this as a break in the RV time series necessitating the definition of a new NEID RV era prior to this date. A sharp FWHM change is also observed for HD 95735, an M-dwarf, but this change does not follow that of the other stars, suggesting a chromatic dependence. Though the ∆FWHM time series for HD 170657 and HD 201091 stand out from the other Solartype stars, these variations reflect changing stellar activity levels rather than an instrumental effect. — astro-ph.EP

    The NEID Earth Twin Survey (NETS) has been delivering a rich set of precise radial velocity (RV) measurements for 41 bright, nearby main sequence stars.

    Here, we describe the status of the survey after three years on sky and we present the full set of RV measurements and accompanying stellar activity indicators. We discuss intermediate survey diagnostics, including calibration of the known RV zero point offset introduced following the Contreras fire in 2022 and the identification of an undiagnosed and previously unknown zero point offset in 2021.

    An analysis of our data set using RVSearch demonstrates that for these target stars, NEID is independently sensitive to nearly all known planets with periods shorter than the NETS observing baseline. We also highlight a number of newly detected RV signals, which present exciting opportunities for future investigations.

    Arvind F. Gupta, Evan Fitzmaurice, Suvrath Mahadevan, Paul Robertson, Jacob K. Luhn, Jason T. Wright, Sarah E. Logsdon, Daniel M. Krolikowski, Leonardo A. Paredes, Chad F. Bender, Mark R. Giovinazzi, Andrea S. Lin, Cullen H. Blake, Caleb I. Cañas, Eric B. Ford, Samuel P. Halverson, Shubham Kanodia, Michael W. McElwain, Joe P. Ninan, Jayadev Rajagopal, Arpita Roy, Christian Schwab, Guðmundur Stefánsson, Ryan C. Terrien

    Comments: Submitted to the Astronomical Journal. 27 Pages, 12 Figures (including 5 Figure sets which are included in the source files)
    Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
    Cite as: arXiv:2506.23704 [astro-ph.EP](or arXiv:2506.23704v1 [astro-ph.EP] for this version)
    https://doi.org/10.48550/arXiv.2506.23704
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    Submission history
    From: Arvind Gupta
    [v1] Mon, 30 Jun 2025 10:27:04 UTC (14,846 KB)
    https://arxiv.org/abs/2506.23704
    Astrobiology,

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  • Thermal Inertia Controls on Titan’s Surface Temperature and Planetary Boundary Layer Structure

    Thermal Inertia Controls on Titan’s Surface Temperature and Planetary Boundary Layer Structure

    On 15 October 1997, NASA’s Cassini orbiter embarked on an epic, seven-year voyage to the Saturnian system. Hitching a ride was ESA’s Huygens probe, destined for Saturn’s largest moon, Titan. The final chapter of the interplanetary trek for Huygens began on 25 December 2004 when it deployed from the orbiter for a 21-day solo cruise toward the haze-shrouded moon. Plunging into Titan’s atmosphere, on 14 January 2005, the probe survived the hazardous 2 hour 27 minute descent to touch down safely on Titan’s frozen surface. Larger image — ESA

    Understanding Titan’s planetary boundary layer (PBL) — the lowest region of the atmosphere influenced by surface conditions — remains challenging due to Titan’s thick atmosphere and limited observations.

    Previous modeling studies have also produced inconsistent estimates of surface temperature, a critical determinant of PBL behavior, often without clear explanations grounded in surface energy balance.

    In this study, we develop a theoretical framework and apply a three-dimensional dry general circulation model (GCM) to investigate how surface thermal inertia influences surface energy balance and temperature variability across diurnal and seasonal timescales. At diurnal timescales, lower thermal inertia surfaces exhibit larger temperature swings and enhanced sensible heat fluxes due to inefficient subsurface heat conduction.

    In contrast, at seasonal timescales, surface temperature variations show weak sensitivity to thermal inertia, as atmospheric damping tends to dominate over subsurface conduction. The PBL depth ranges from a few hundred meters to 1,000 m on diurnal timescales, while seasonal maxima reach 2,000–3,000 m, supporting the interpretation from a previous study that the Huygens probe captured the two PBL structures.

    Simulated seasonal winds at the Huygens landing site successfully reproduce key observed features, including near-surface retrograde winds and meridional wind reversals within the lowest few kilometers, consistent with Titan’s cross-equatorial Hadley circulation.

    Simulations at the planned Dragonfly landing site predict shallower thermal PBLs with broadly similar wind patterns. This work establishes a physically grounded framework for understanding Titan’s surface temperature and boundary layer variability, and offers a unified explanation of Titan’s PBL behavior that provides improved guidance for future missions.

    Sooman Han, Juan M. Lora

    Comments: 25 pages, 11 figures
    Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph)
    Cite as: arXiv:2506.23477 [astro-ph.EP] (or arXiv:2506.23477v1 [astro-ph.EP] for this version)
    https://doi.org/10.48550/arXiv.2506.23477
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    Submission history
    From: Sooman Han
    [v1] Mon, 30 Jun 2025 02:46:00 UTC (6,806 KB)
    https://arxiv.org/abs/2506.23477
    Astrobiology,

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  • Characterizing the Dynamics and Chemistry of Transiting Exoplanets with the Habitable World Observatory

    Characterizing the Dynamics and Chemistry of Transiting Exoplanets with the Habitable World Observatory

    To understand where the measured flux from the planet is coming from we need to capture both reflected and thermal components of the light from the planet. This requires broad wavelength coverage from <0.5 to >1 micron. Predicted planetary reflected signal vs. thermal emission for archetypal planets (letters correspond to planet properties shown in the inset plot) identified by Mayorga et al. (2019). Top: the total planetary flux as measured in flux units. Bottom: the percent contribution of reflected light to the total flux as a function of wavelength (R 300). Colored bands in the top panel show the photometric (hashed) and spectroscopic (solid) coverage from current and future facilities over this wavelength range. Figure courtesy of L. C. Mayorga. — astro-ph.EP

    The primary scientific objective of this Habitable Worlds Observatory (HWO) Science Case Development Document (SCDD) is to measure planetary rotation rates of transiting exoplanets to determine the structure, composition, circulation, and aerosol properties of their planetary atmospheres.

    For this analysis, HWO would obtain spectroscopic phase curves for planets with orbital periods of 5 – 20+ days, to assess tidal locking radius assumptions. Extending phase curve studies out to longer orbital periods than accessible with current and near-future telescopes will enable detailed investigation of atmospheric structure, composition, and circulation for planets that are much cooler than the more highly irradiated planets accessible with JWST phase curve observations (i.e., Teq < 500 K for HWO versus 1400 K <= Teq <= 2600 K for JWST).

    Broad wavelength coverage extending from the UV to the NIR would capture both reflected light and thermal emission, enabling HWO to conduct comprehensive characterization of planetary atmospheres. UV observations would probe high altitudes, thereby providing valuable insights into atmospheric (dis)equilibrium, aerosol properties, and the effects of photochemical processes on atmospheric composition.

    We also discuss the role of polarimetry in the classification of aerosols and the associated role they play in the atmospheric energy budget that directly ties them to the chemistry and circulation structure of the atmosphere.

    Hannah R. Wakeford, Laura C. Mayorga, Joanna K. Barstow, Natasha E. Batalha, Ludmila Carone, Sarah L. Casewell, Theodora Karalidi, Tiffany Kataria, Erin M. May, Michiel Min

    Comments: Towards the Habitable Worlds Observatory: Visionary Science and Transformational Technology SCDD, to be presented at HWO2025 and submitted to Astronomical Society of the Pacific following community comments. Feedback welcomed
    Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
    Cite as: arXiv:2506.22839 [astro-ph.EP] (or arXiv:2506.22839v1 [astro-ph.EP] for this version)
    https://doi.org/10.48550/arXiv.2506.22839
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    Submission history
    From: Hannah R Wakeford
    [v1] Sat, 28 Jun 2025 10:40:20 UTC (1,037 KB)
    https://arxiv.org/abs/2506.22839
    Astrobiology,

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  • Science Unveils Young Anaconda’s Slithering Secrets

    Science Unveils Young Anaconda’s Slithering Secrets

    The motion of snakes has long fascinated humans: they undulate, they sidewind, they crawl, they even fly .

    Together with herpetologists, researchers in the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have discovered and quantified a new type of locomotion in juvenile anacondas.

    As adults, these large snakes are better known for their slow, lumbering gait, but the researchers discovered that young anacondas are much more spry — capable of a quick, one-off, skating movement the researchers dubbed the “S-start” due to the shape the snake makes with its body.

    A team led by SEAS professor L. Mahadevan , the Lola England de Valpine Professor of Applied Mathematics, Physics and Organismic and Evolutionary Biology in SEAS and the Faculty of Arts and Sciences, is the first to describe this peculiar movement using a mathematical model that quantifies exactly how the snake executes it. The research is published in Nature Physics .

    “This movement is the serpentine analog of the moonwalk – a fast, graceful glide that seems to defy common sense,” Mahadevan said. “We used observations to create a mathematical framework, in order to understand under what conditions movements like this are possible, and why they are lost as the snake gets older, heavier, and relatively less strong.”

    Study co-author and Missouri herpetologist Bruce Young first noticed several years ago that young anacondas, when gently prodded, displayed what he could only describe as a startle reflex. “This behavior involved not only forming the body into a very characteristic shape, and moving using a gait previously undescribed from snakes, but also moving remarkably fast,” Young said, noting that anacondas are known for their mass and strength, but not for their speed. “It was clear to me that this was something new, involving different biophysics, than what had been described in snakes.”

    Young had at this point never met Mahadevan but was a “big fan” of his work – “He has such a mastery of describing and modeling shape and movement” – that Young pitched to Mahadevan a collaborative analysis. The result was the Nature Physics study, co-authored by former Harvard graduate student Nicholas Young and Indian Institute of Technology Bombay researcher Raghu Chelakkot, who developed the computational model to quantify the movement, along with Mattia Gazzola from the University of Illinois.

    In their computational analysis, backed up by experiment and observation, the Harvard researchers found that the S-start is present in a “goldilocks” zone of an anaconda’s weight and relative strength. An adult snake is too heavy to execute the movement, while a newborn snake is too strong and tends to either flail upward or unravel. A youthful anaconda has just the right physical attributes to perform the S-start, in which it neither flies off the ground, nor is it overwhelmed by ground friction.

    In describing the S-start, Mahadevan’s team helped correct misconceptions about the better-known sidewinding – the continuous, sideways motion snakes use to slide down sandy hills. In their analysis they found that the S-starts are “non-planar,” as in, some segments of the snake are off the ground, almost as if the snake were walking. “We realized that the sidewinding motion is very similar to this S-motion, in that it consists of S-starts that are repeated again and again,” Mahadevan said.

    “Perhaps, from an evolutionary point of view, this transient movement was taken up and then repeated, and this became the origin of sidewinding,” Mahadevan said. Overall, the findings seed new insights into how the S-start reflex works in snakes and could serve to inspire new robotic systems or other innovations.

    The research was supported by National Science Foundation grants: BioMatter Division of Material Research 1922321, Materials Research Science and Engineering Centers Division of Materials Research 2011754, and Emerging Frontiers of Multidisciplinary Activities 1830901.

    /Public Release. This material from the originating organization/author(s) might be of the point-in-time nature, and edited for clarity, style and length. Mirage.News does not take institutional positions or sides, and all views, positions, and conclusions expressed herein are solely those of the author(s).View in full here.

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  • Synthetic proteins are being built with the help of AI models

    Synthetic proteins are being built with the help of AI models

    Making biofuels is messy, inefficient and expensive. Vast quantities of crops such as maize and soyabeans must be grown, harvested and processed before their energy, accumulated slowly through natural photosynthesis, can be put to use. Nate Ennist of the Institute for Protein Design (IPD) at the University of Washington, in Seattle, thinks that synthetic proteins can boost the rate of return.

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  • A new project aims to synthesise a human chromosome

    A new project aims to synthesise a human chromosome

    WHEN THE first draft of the DNA sequence that makes up the human genome was unveiled in 2000, America’s president at the time, Bill Clinton, announced that humankind was “learning the language with which God created life”. His assessment was a little quick off the mark. For one thing, the full sequence would not be completed until 2022. For another, whereas scientists can use sequencing tools to read DNA, and CRISPR technology to make small edits, actually writing the genomic language has proved trickier.

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  • Astronomy enters its digital age

    Astronomy enters its digital age

    The Vera Rubin Observatory is about to start a decade-long survey of the night sky. In the process, it will generate hundreds of petabytes of astronomical data. Hidden within that firehose of information will be clues about some of the universe’s deepest mysteries—from dark matter and dark energy to the evolution of galaxies. To help scientists unlock those new celestial tales, the Rubin Observatory’s team had to invent a bespoke way to organise, analyse and share the data. That technology, which will usher in a new, automated era for astronomy, may be one of the observatory’s most important and enduring legacies.

    In the second of two episodes, we visit the Rubin Observatory, 2,700m high in the Chilean Andes, to uncover how the telescope’s data travel from the summit to astronomers’ desks around the world. Listen to the first episode here.

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  • Possible Interstellar Object Zooming Through Solar System: ESA – Barron's

    Possible Interstellar Object Zooming Through Solar System: ESA – Barron's

    1. Possible Interstellar Object Zooming Through Solar System: ESA  Barron’s
    2. A11pl3Z: Interstellar visitor spotted hurtling through the solar system  New Scientist
    3. Astronomers may have found a third interstellar object  Ars Technica
    4. BREAKING: New interstellar object candidate heading toward the sun  EarthSky
    5. We May Have Our Third Interstellar Visitor And It’s Nothing Like The Previous Two  IFLScience

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