Evolution in real time

ISTA scientists predict—and witness—evolution in a 30-year marine snail experiment

Institute of Science and Technology Austria

 

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Crab-ecotype snails (1992) evolved to strikingly resemble the lost Wave-ecotype snails on a skerry.

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Credit: ISTA, images by Kerstin Johannesson

It is 1988. The Koster archipelago, a group of islands off the Swedish west coast near the border with Norway, is hit by a particularly dense bloom of toxic algae, wiping out marine snail populations. But why would anyone care about the fate of a bunch of snails on a three-square-meter rock in the open sea? As it turns out, this event would open up the opportunity to predict and see evolution unfolding before our eyes.

Before, the islands and their small intertidal skerries—rocky islets—were home to dense and diverse populations of marine snails of the species Littorina saxatilis. While the snail populations of the larger islands—some of which were reduced to less than 1%—were restored within two to four years, several skerries could not seem to recover from this harsh blow.

Marine ecologist Kerstin Johannesson from the University of Gothenburg, Sweden, saw a unique opportunity. In 1992, she re-introduced L. saxatilis snails to their lost skerry habitat—starting an experiment that would have far-reaching implications more than 30 years later. It allowed an international collaboration led by researchers from the Institute of Science and Technology Austria (ISTA), Nord University, Norway, the University of Gothenburg, Sweden, and The University of Sheffield, UK, to predict and witness evolution in the making.

Wave snails and Crab snails

L. saxatilis is a common species of marine snails found throughout the North Atlantic shores, where different populations evolved traits adapted to their environments. These traits include size, shell shape, shell color, and behavior. The differences among these traits are particularly striking between the so-called Crab- and Wave-ecotype. These snails have evolved repeatedly in different locations, either in environments exposed to crab predation or on wave-exposed rocks away from crabs. Wave snails are typically small, and have a thin shell with specific colors and patterns, a large and rounded aperture, and bold behavior. Crab snails, on the other hand, are strikingly larger, have thicker shells without patterns, and a smaller and more elongated aperture. Crab snails also behave more warily in their predator-dominated environment.

The Swedish Koster archipelago is home to these two different L. saxatilis snail types, often neighboring one another on the same island or only separated by a few hundred meters across the sea. Before the toxic algal bloom of 1988, Wave snails inhabited the skerries, while nearby shores were home to both Crab and Wave snails. This close spatial proximity would prove crucial.

Rediscovering old traits

Seeing that the Wave snail population of the skerries was entirely wiped out due to the toxic algae, Johannesson decided in 1992 to reintroduce snails to one of these skerries, but of the Crab-ecotype. With one to two generations each year, she rightfully expected the Crab snails to adapt to their new environment before scientists’ eyes. “Our colleagues saw evidence of the snails’ adaptation already within the first decade of the experiment,” says Diego Garcia Castillo, a graduate student in the Barton Group at ISTA and one of the authors leading the study. “Over the experiment’s 30 years, we were able to predict robustly what the snails will look like and which genetic regions will be implicated. The transformation was both rapid and dramatic,” he adds.

However, the snails did not evolve these traits entirely from scratch. Co-corresponding author Anja Marie Westram, a former postdoc at ISTA and currently a researcher at Nord University, explains, “Some of the genetic diversity was already available in the starting Crab population but at low prevalence. This is because the species had experienced similar conditions in the recent past. The snails’ access to a large gene pool drove this rapid evolution.”

Diversity is key to adaptation

The team examined three aspects over the years of the experiment: the snails’ phenotype, individual gene variabilities, and larger genetic changes affecting entire regions of the chromosomes called “chromosomal inversions”.

In the first few generations, the researchers witnessed an interesting phenomenon called “phenotypic plasticity”: Very soon after their transplantation, the snails modified their shape to adjust to their new environment. But the population also quickly started to change genetically. The researchers could predict the extent and direction of the genetic changes, especially for the chromosomal inversions. They showed that the snails’ rapid and dramatic transformation was possibly due to two complementary processes: A fast selection of traits already present at a low frequency in the transplanted Crab snail population and gene flow from neighboring Wave snails that could have simply rafted over 160 meters to reach the skerry.

Evolution in the face of pollution and climate change

In theory, scientists know that a species with high enough genetic variation can adapt more rapidly to change. However, few studies aimed to experiment with evolution over time in the wild. “This work allows us to have a closer look at repeated evolution and predict how a population could develop traits that have evolved separately in the past under similar conditions,” says Garcia Castillo.

The team now wants to learn how species can adapt to modern environmental challenges such as pollution and climate change. “Not all species have access to large gene pools and evolving new traits from scratch is tediously slow. Adaptation is very complex and our planet is also facing complex changes with episodes of weather extremes, rapidly advancing climate change, pollution, and new parasites,” says Westram. She hopes this work will drive further research on maintaining species with large and diverse genetic makeups. “Perhaps this research helps convince people to protect a range of natural habitats so that species do not lose their genetic variation,” Westram concludes.

Now, the snails Johannesson brought to the skerry in 1992 have reached a thriving population of around 1,000 individuals.

Two ecotypes of Littorina saxatilis marine snails, adapted to different environments. 

The Crab ecotype (left) is larger and wary of predators. The Wave ecotype (right) is smaller and has bold behavior.

Credit

David Carmelet

The donor shore of the transplanted snail population (foreground) and the experimental skerry (little dot in the sea to the right).

The experimental skerry in the Koster archipelago off the Swedish west coast. 

Crab-ecotype L. saxatilis snails were brought here in 1992 after toxic algae wiped out the original Wave-ecotype population.

Credit

Kerstin Johannesson

Kerstin Johannesson on the experimental skerry 

Johannesson is a marine ecologist at the University of Gothenburg, Sweden.

Credit

Bo Johannesson

First author Diego Garcia Castillo, graduate student at ISTA, visiting the experimental skerry.

Credit

Pierre Barry

Swedish L. saxatilis marine snails.

Credit

Daria Shipilina

Information on animal studies

To better understand fundamental processes, for example, in the fields of neuroscience, immunology, or genetics, the use of animals in research is indispensable. No other methods, such as in silico models, can serve as an alternative. The animals are raised, kept, and treated according to the strict regulations of the respective countries. The research with animals was conducted in Sweden.

About ISTA

The Institute of Science and Technology Austria (ISTA) is a PhD-granting research institution located in Klosterneuburg, 18 km from the center of Vienna, Austria. ISTA employs professors on a tenure-track model, post-doctoral researchers and PhD students. The Graduate School of ISTA offers fully funded PhD positions to highly qualified candidates with a Bachelor’s or Master’s degree in biology, mathematics, computer science, physics, chemistry, and related areas. While dedicated to the principle of curiosity-driven research, ISTA aims to deliver scientific findings to society through technological transfer and science education. President of the Institute is Martin Hetzer, a renowned molecular biologist and former Senior Vice President at The Salk Institute for Biological Studies in California, USA. www.ista.ac.at

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Journal

Science Advances

DOI

10.1126/sciadv.adp2102 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Predicting rapid adaptation in time from adaptation in space: A 30-year field experiment in marine snails

Article Publication Date

11-Oct-2024

 

Coffee during pregnancy safe for baby’s brain development

A University of Queensland-led study has failed to find any strong links between drinking coffee during pregnancy and neurodevelopmental difficulties in children

University of Queensland

A University of Queensland-led study has failed to find any strong links between drinking coffee during pregnancy and neurodevelopmental difficulties in children, but researchers are advising expectant mothers to continue following medical guidelines on caffeine consumption.  

Dr Gunn-Helen Moen and PhD student Shannon D’Urso from UQ’s Institute for Molecular Bioscience (IMB) led an in-depth genetic analysis of data from tens of thousands of families in Norway.  

“Scandinavians are some of the biggest coffee consumers in the world, drinking at least 4 cups a day, with little stigma about drinking coffee during pregnancy,” Dr Moen said.

“Our study used genetic data from mothers, fathers and babies as well as questionnaires about the parents’ coffee consumption before and during pregnancy.

“The participants also answered questions about their child’s development until the age of 8, including their social, motor, and language skills.”

“Our analysis found no link between coffee consumption during pregnancy and children’s neurodevelopmental difficulties.”

The researchers said physiological changes during pregnancy prevent caffeine breaking down easily and it can cross the placenta and reach the foetus, where there are no enzymes to metabolise it.

Caffeine accumulation was thought to impact the developing foetal brain, but Dr Moen said previous observational studies couldn’t account for other environmental factors such as alcohol, cigarette smoke or poor diet.

“We used a method called Mendelian randomisation which uses genetic variants that predict coffee drinking behaviour and can separate out the effect of different factors during pregnancy,” she said.

“It mimics a randomised controlled trial without subjecting pregnant mothers and their babies to any ill effects.

“The benefit of this method is the effects of caffeine, alcohol, cigarettes and diet can be separated in the data, so we can look solely at the impact of caffeine on the pregnancy.”

The researchers use genetic analysis to understand complex traits and diseases especially in early life, with a previous study by Dr Moen showing that drinking coffee in pregnancy did not affect birth weight, risk of miscarriage or stillbirth.

They emphasise the importance of following advice from healthcare providers to limit caffeine consumption during pregnancy, as caffeine may influence other pregnancy outcomes.

The researchers are now looking to apply similar analyses to understand more about genetic and environmental causes of neurodiversity, and the effect of it from other factors on brain development during pregnancy.

The research team included international collaborators in Norway including Professor Alexandra Havdahl from PsychGen Center for Genetic Epidemiology and Mental Health, Norwegian Institute of Public Health, Oslo and England as well as IMB’s Caroline Brito Nunes, Dr Daniel Hwang and Professor David Evans. The research was conducted using data from the Norwegian Mother, Father and Child Cohort Study (MoBa).

The research was published in Psychological Medicine.

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Journal

Psychological Medicine

DOI

10.1017/S0033291724002216 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Mendelian Randomization Analysis of Maternal Coffee Consumption During Pregnancy on Offspring Neurodevelopmental Difficulties in the Norwegian Mother, Father and Child Cohort Study (MoBa)

Article Publication Date

9-Oct-2024

 SPACE/COSMOS

The european project ‘ZEUS’ seeks to collect in-space solar energy in an efficient, long-lasting way

It has been granted almost €4 million for the development of a new photovoltaic technology over the next 4 years

University of Malaga

 

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Specifically, ‘ZEUS’ will focus on advancing the development of nanowire solar cells, a highly innovative, radiation-resistant photovoltaic technology capable of absorbing solar energy in space, where the environment is highly aggressive.

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Credit: University of Malaga

The University of Malaga, through the Materials and Surfaces Laboratory, participates in an international consortium that has received one of the eight grants ‘Horizon EIC Pathfinder Challenges - In-space solar energy harvesting for innovative space applications’ that have been awarded this year at European level, with the aim of achieving significant advances in the fields of in-space solar energy collection and transmission and the new concepts of propulsion that will be used by the energy obtained.

 

Coordinated by the University of Lund (Sweden), the ‘ZEUS’ -Zero-loss energy harvesting using nanowire solar cells in space- project has been granted almost €4 million (€3,998,622.50) for its development over the next four years. The other participants that, together with the UMA, make up this project are the Fraunhofer Institute for Solar Energy Systems ISE (Germany), the Polytechnic University of Valencia and the Technological Institute of Packaging, Transport and Logistics.

 

An innovative, radiation-resistant photovoltaic technology 

Specifically, ‘ZEUS’ will focus on advancing the development of nanowire solar cells, a highly innovative, radiation-resistant photovoltaic technology capable of absorbing solar energy in space, where the environment is highly aggressive.

Nanowires are needle-shaped structures with a diameter of 200 nanometers –that is, a thousand times thinner than human hair–, explains Enrique Barrigón, Professor of the Department of Applied Physics I, the researcher who will lead this project at the UMA. Their nanometric scale and careful geometric distribution make them behave as “hollow” devices from the point of view of radiation damage, which significantly increases their resistance to radiation, while effectively collecting nearly one hundred percent of the possible incoming light, due to the improved optical absorption that occurs in these cells. 

“Covering approximately 10 percent of a surface with active material is all that is needed to absorb as much light as a thin layer covering the entire surface of the same material would do,” says the UMA researcher.

Greater efficiency

In this respect, Enrique Barrigón explains that while current space-tested nanowire solar cells offer around 15% efficiency, ZEUS aims to significantly enhance this efficiency by employing triple junction nanowire cells with a carefully selected set of III-V semiconductor materials, potentially reaching 47% theoretical efficiency. 

Likewise, this project will investigate the transfer of these solar cells onto lightweight, flexible substrates, which would enable the creation of large deployable photovoltaic panels.

Environmental sustainability

Additionally, the project underscores its commitment to sustainability by focusing on two key aspects: decarbonization and the efficient use of critical raw materials. “ZEUS aims to demonstrate not only the commercial potential of the technology, but also the environmental benefits by means of a life cycle assessment of nanowire solar cells, particularly for space energy generation”, says Professor Enrique Barrigón. Thus, increasing the electrical power of communications satellites is one of its possible applications, among others.

The main tasks of the University of Malaga in this international research will be the advanced characterization of these solar cells and the execution of the necessary tests to evaluate their resistance in the space environment.

The other participants that, together with the UMA, make up this project are the Fraunhofer Institute for Solar Energy Systems ISE (Germany), the Polytechnic University of Valencia and the Technological Institute of Packaging, Transport and Logistics. 

Enrique Barrigón, Professor of the Department of Applied Physics I, the researcher who will lead this project at the UMA

Credit

University of Malaga

The european project ‘ZEUS’ se [VIDEO] | 

Revolutionary technology

The Horizon EIC Pathfinder Challenges program  awards grants to projects that explore new technological areas, especially ‘deep-tech’ –based on a scientific discovery or a significant engineering innovation– which may become radically innovative technologies in the future, capable of creating new market opportunities. The overall goal is to feed the innovation market with revolutionary technologies and get them to the proof-of-concept stage.

 

So far, within the current Horizon Europe framework, the University of Malaga has another project of this same program. This is ‘BioRobot-MiniHeart’, whose principal researcher is Juan Antonio Guadix, from the Department of Animal Biology. In the previous H2020 program, another proposal from the UMA was also recognized: ‘SONICOM’ -Transforming auditory-based social interaction and communication in AR/VR-, by Professor Arcadio Reyes, Department of Electronic Technology.

This project has been funded through the European Union Research and Innovation Program, Horizon Europe, with Grant Agreement 101161465.

"Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.”

SwRI-led instrument aboard Jupiter-bound spacecraft nails in-flight test

The Ultraviolet Spectrograph demonstrated its accuracy and reliability

Southwest Research Institute

 

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The UVS instrument recorded spatial information produced by hydrogen atoms radiating from the Earth. In the background a number of individual stars are identified along with the Pleiades star cluster. Juice-UVS plans to similarly observe hydrogen atoms radiating from Ganymede and Jupiter’s other icy moons.

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Credit: Southwest Research Institute

SAN ANTONIO — October 9, 2024 —As European Space Agency (ESA)’s Jupiter Icy Moons Explorer (Juice) spacecraft hurtled past the Moon and Earth in mid-August to provide its first gravity assist maneuver to the Jovian system, the Southwest Research Institute-led Ultraviolet Spectrograph (UVS) instrument imaged the UV emissions radiating from the Earth and Moon.

It was a successful test of one of three science instrument projects comprising NASA’s contribution to ESA’s Juice mission. The UVS data collected were then analyzed and found to be consistent with expectations for the Moon and the Earth. This confirmation that the instrument works within specifications was not able to be fully achieved during pre-launch testing in a laboratory setting.

“This high-fidelity test confirmed what the instrument is supposed to do. We can now be confident that the data we will get from Jupiter’s moons will be just as accurate,” said SwRI’s Steven Persyn, Juice-UVS project manager (PM).

Weighing just over 40 pounds and drawing only 7.5 watts of power, UVS is smaller than a microwave oven, yet this powerful instrument will determine the relative concentrations of various elements and molecules in the atmospheres of Jupiter’s moons once in the Jovian system.

Aboard Juice, UVS will get close-up views of the Galilean moons Europa, Ganymede and Callisto, all thought to host liquid water beneath their icy surfaces. UVS will record ultraviolet light emitted, transmitted and reflected by these bodies, revealing the composition of their surfaces and tenuous atmospheres and how they interact with Jupiter and its giant magnetosphere. Additional scientific goals include observations of Jupiter itself as well as the gases from its volcanic moon Io that spread throughout the Jovian magnetosphere.

The Juice spacecraft is now on its way to Venus, where it will complete a gravity assist maneuver before heading back to Earth for another gravity assist to attain the momentum needed for its journey to the Jovian system.

The mission’s science goals focus on Jupiter and its system, making multiple flybys of the planet’s large, ocean-bearing satellites with a particular emphasis on investigating Ganymede as a potentially habitable planetary body. Being the only moon in the solar system known to have an internal magnetic field, Ganymede has auroral ovals like the northern and southern lights on Earth. The UV emissions from Earth’s atmosphere observed during the recent gravity assists provide an especially good test of the plans for Juice-UVS to observe Ganymede’s UV aurora and other atmospheric features.  It will also study the system as an archetype for gas giants in our solar system and beyond.

UVS is one of 10 science instruments and 11 investigations on the Juice spacecraft. As it begins an approximately 4.1-billion-mile (6.6-billion-kilometer), eight-year journey to the Jupiter system, the spacecraft has been busy deploying and activating its antennas, booms, sensors and instruments to check out and commission all its important subsystems. SwRI’s UVS instrument is the latest to succeed in this task.

A similar instrument, Europa-UVS, will travel aboard NASA’s Europa Clipper, which will take a more direct route to arrive at the Jupiter system 15 months before Juice and focus on studying the potential habitability of Europa.

“Our UVS instrument will complement the work that will be done by Europa-UVS allowing us to learn even more at the same time,” said SwRI’s Dr. Kurt Retherford, principal investigator (PI) of Europa-UVS and deputy PI for Juice-UVS. “Having both teams working with the UVS instruments based here at SwRI will make that coordination all the more efficient.”

The Juice spacecraft and science instruments were built by teams from 15 European countries, Japan and the United States. SwRI’s UVS instrument team includes additional scientists from the University of Colorado Boulder, the SETI institute, the University of Leicester (U.K.), Imperial College London (U.K.), the University of Liège (Belgium), the Royal Institute of Technology (Sweden) and the Laboratoire Atmosphères, Milieux, Observations Spatiales (France). The Planetary Missions Program Office at NASA’s Marshall Space Flight Center oversees the UVS contribution to ESA through the agency’s Solar System Exploration Program. The Juice spacecraft was developed by Airbus Defence and Space.  

For more information, visit https://www.swri.org/planetary-science.

Leicester spinout company Perpetual Atomics to transform power generation in space

Space Park Leicester and the University of Leicester to launch new space nuclear power systems, space science and exploration spin-out company at International Astronautical Congress (IAC) – Perpetual Atomics Ltd

University of Leicester

 

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The space nuclear power programme team.

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Credit: University of Leicester/Space Park Leicester

Transformative technology that harnesses the power of nuclear material for space missions is set to enable a whole range of new space missions as Space Park Leicester launches Perpetual Atomics, a bold new start-up to commercialise its research.

The University of Leicester is excited to announce the launch of a new spin-out company, Perpetual Atomics, which is set to revolutionise the application of nuclear technology in space.

Perpetual Atomics is a space nuclear power systems, space science and exploration business that will commercialise the know-how and expertise in space nuclear power developed over more than 20 years at the University of Leicester.

Perpetual Atomics, will aim to bring innovative solutions to power challenges in space missions, ensuring sustainability and reliability in some of the harshest environments known to humanity.

Perpetual Atomics will be announced to visitors of International Astronautical Congress 2024 on the UK Space Agency stand, MS-B05, on Tuesday 15 October.

Professor Richard Ambrosi, Executive Director of Space Park Leicester, said: “Since Space Park Leicester last attended the International Astronautical Congress we’ve seen some exciting developments in space nuclear power, and we are delighted to be able to share more on those at 75th International Astronautical Congress (IAC) in Milan this October.

“We are entering a new chapter in our journey, one that will see us harness the potential of nuclear technology to power deep space exploration and to pioneer new frontiers and are ready to bring others with us on that journey. The use of nuclear power in space is not just a concept for the future—it’s happening now.”

Building on the success of attendance in Paris in 2022, a team of leading experts from the University of Leicester’s space nuclear division will be present in Milan, showcasing cutting-edge advancements and discussing the future of nuclear power in space exploration.

The technology at the heart of the new venture has the potential to enable longer, more ambitious missions beyond Earth’s orbit in some of the harshest environments of deep space. Perpetual Atomics aims to establish a new global market leader in mature radioisotope power solutions based on research from the University of Leicester.

Perpetual Atomics’ mission builds on two decades work in developing radioisotope power systems by the Space Nuclear Power group at the University of Leicester. These power systems use the heat generated from the decay of radioisotopes, and can be used to provide heat to spacecraft, or converted to electricity to power key subsystems. Their Radioisotope Heater Units (RHUs) and Radioisotope Thermoelectric Generator or RTG (also sometimes referred to as a 'space battery') use americium fuel, which can provide stable power outputs to spacecraft for many decades.

Based at Space Park Leicester, the University of Leicester’s £100 million science and innovation park, where a space nuclear power community is being developed, the team are the main developer of radioisotope thermoelectric generators in Europe. The technology development has been funded by the European Space Agency (ESA) European Devices Using Radioisotope Energy (ENDURE) program, as well as the UK Space Agency.

The Perpetual Atomics team is looking forward to working with a number of national and international partners to expand the use of radioisotope power technologies in space.

The investment in Perpetual Atomics has been made by Reef Global, the impact investment division within Reef Origin. Piers Slater, Reef Global Executive Chairman & Chief Executive Officer at Perpetual Atomics commented: “We are very excited that our first investment in the space sector is in Perpetual Atomics a business aligned with Reef Global’s goal to deliver a sustainable earth and space economy.  We thank both University of Leicester and the co-founders for giving us the opportunity to invest in and support the commercialisation and scale up of Perpetual Atomics an innovative and exciting business led by a talented team with the shared ambitions of building a pioneering global space company from the UK.” 

Professor Sarah Davies, Pro Vice-Chancellor and Head of the College of Science and Engineering at the University of Leicester said: “Perpetual Atomics is an exemplar of the type of business that Space Park Leicester was established to create: originating from world-leading research that has been nurtured at the University of Leicester for many years, and enabled by the dedicated, highly skilled and innovative community at our flagship Space Park Leicester. The spin-out launch will seize an opportunity that is already pushing new frontiers for the space industry globally, and we are excited to see it do the same for humanity’s exploration beyond our world. It also further cements Leicester’s place as the UK’s Space City, building on our city’s long heritage in space and its contribution to the region’s economy.”

Julie Black, Director of Missions and Capabilities at the UK Space Agency, said: "The University of Leicester has long been at the forefront of world leading research into innovative space technologies. This addition of an exciting new start-up to Space Park Leicester continues this tradition of innovation and highlights the skilled workforce in the region.

"The cutting-edge technology that the team at Perpetual Atomics are developing could not only harness nuclear power to sustain exploration of space for longer periods of time but allow us to venture further into space than ever before, enabling more science and bringing more benefits back to Earth.”

William Wells, Deputy Director Research and Enterprise at the University of Leicester, said: “At the University of Leicester we are committed to seeing our globally leading research deliver real world impact, Perpetual Atomics will transform power solutions for space and will form part of a growing community of innovative energy businesses at Space Park.  In addition it becomes a further business at Space Park spun out of research at Leicester.”

Professor Sarah Davies, Pro Vice-Chancellor and Head of the College of Science and Engineering, and Professor Richard Ambrosi, Executive Director of Space Park Leicester.

Shock Test (IMAGE)

University of Leicester

 

Radioisotope Thermoelectric Generator being subjected to extreme shock levels to test its resilience for the harsh environment of a launch or planetary surface landing.

Lunar rover powered by an Radioisotope Thermoelectric Generator.

Credit

University of Leicester/Space Park Leicester

NASA’s Hubble, New Horizons team up for a simultaneous look at Uranus

NASA/Goddard Space Flight Center

 

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NASA's Hubble Space Telescope (left) and NASA's New Horizon's spacecraft (right) image the planet Uranus.

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Credit: NASA, ESA, STScI, Samantha Hasler (MIT), Amy Simon (NASA-GSFC), New Horizons Planetary Science Theme Team; Image Processing: Joseph DePasquale (STScI), Joseph Olmsted (STScI)

NASA's Hubble Space Telescope and New Horizons spacecraft simultaneously set their sights on Uranus recently, allowing scientists to make a direct comparison of the planet from two very different viewpoints. The results inform future plans to study like types of planets around other stars.

Astronomers used Uranus as a proxy for similar planets beyond our solar system, known as exoplanets, comparing high-resolution images from Hubble to the more-distant view from New Horizons. This combined perspective will help scientists learn more about what to expect while imaging planets around other stars with future telescopes.

"While we expected Uranus to appear differently in each filter of the observations, we found that Uranus was actually dimmer than predicted in the New Horizons data taken from a different viewpoint," said lead author Samantha Hasler of the Massachusetts Institute of Technology in Cambridge and New Horizons science team collaborator.

Direct imaging of exoplanets is a key technique for learning about their potential habitability, and offers new clues to the origin and formation of our own solar system. Astronomers use both direct imaging and spectroscopy to collect light from the observed planet and compare its brightness at different wavelengths. However, imaging exoplanets is a notoriously difficult process because they're so far away. Their images are mere pinpoints and so are not as detailed as the close-up views that we have of worlds orbiting our Sun. Researchers can also only directly image exoplanets at "partial phases," when only a portion of the planet is illuminated by their star as seen from Earth.

Uranus was an ideal target as a test for understanding future distant observations of exoplanets by other telescopes for a few reasons. First, many known exoplanets are also gas giants similar in nature. Also, at the time of the observations, New Horizons was on the far side of Uranus, 6.5 billion miles away, allowing its twilight crescent to be studied—something that cannot be done from Earth. At that distance, the New Horizons view of the planet was just several pixels in its color camera, called the Multispectral Visible Imaging Camera.

On the other hand, Hubble, with its high resolution, and in its low-Earth orbit 1.7 billion miles away from Uranus, was able to see atmospheric features such as clouds and storms on the day side of the gaseous world.

"Uranus appears as just a small dot on the New Horizons observations, similar to the dots seen of directly-imaged exoplanets from observatories like Webb or ground-based observatories," added Hasler. "Hubble provides context for what the atmosphere is doing when it was observed with New Horizons."

The gas giant planets in our solar system have dynamic and variable atmospheres with changing cloud cover. How common is this among exoplanets? By knowing the details of what the clouds on Uranus looked like from Hubble, researchers are able to verify what is interpreted from the New Horizons data. In the case of Uranus, both Hubble and New Horizons saw that the brightness did not vary as the planet rotated, which indicates that the cloud features were not changing with the planet’s rotation.

However, the importance of the detection by New Horizons has to do with how the planet reflects light at a different phase than what Hubble, or other observatories on or near Earth, can see. New Horizons showed that exoplanets may be dimmer than predicted at partial and high phase angles, and that the atmosphere reflects light differently at partial phase.

NASA has two major upcoming observatories in the works to advance studies of exoplanet atmospheres and potential habitability.

“These landmark New Horizons studies of Uranus from a vantage point unobservable by any other means add to the mission’s treasure trove of new scientific knowledge, and have, like many other datasets obtained in the mission, yielded surprising new insights into the worlds of our solar system,” added New Horizons principal investigator Alan Stern of the Southwest Research Institute.

NASA's upcoming Nancy Grace Roman Space Telescope, set to launch by 2027, will use a coronagraph to block out a star’s light to directly see gas giant exoplanets. NASA’s Habitable Worlds Observatory, in an early planning phase, will be the first telescope designed specifically to search for atmospheric biosignatures on Earth-sized, rocky planets orbiting other stars.

“Studying how known benchmarks like Uranus appear in distant imaging can help us have more robust expectations when preparing for these future missions,” concluded Hasler. “And that will be critical to our success.”

Launched in January 2006, New Horizons made the historic flyby of Pluto and its moons in July 2015, before giving humankind its first close-up look at one of these planetary building block and Kuiper Belt object, Arrokoth, in January 2019. New Horizons is now in its second extended mission, studying distant Kuiper Belt objects, characterizing the outer heliosphere of the Sun, and making important astrophysical observations from its unmatched vantage point in distant regions of the solar system.

The Uranus results are being presented this week at the 56th annual meeting of the American Astronomical Society Division for Planetary Sciences, in Boise, Idaho.

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

The Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, built and operates the New Horizons spacecraft and manages the mission for NASA's Science Mission Directorate. Southwest Research Institute, based in San Antonio and Boulder, Colorado, directs the mission via Principal Investigator Alan Stern and leads the science team, payload operations and encounter science planning. New Horizons is part of NASA's New Frontiers program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama.

@NASAHubble

@NASAHubble

@NASAHubble

Method of Research

Observational study

Lightning strikes kick off a game of electron pinball in space

University of Colorado at Boulder

When lightning strikes, the electrons come pouring down.

In a new study, researchers at the University of Colorado Boulder led by an undergraduate student have discovered a new link between weather on Earth and weather in space. The group used satellite data to show that lightning storms on our planet can knock especially high-energy, or “extra-hot,” electrons out of the inner radiation belt—a region of space filled with charged particles that surrounds Earth like an inner tube.

The team’s results could help satellites and even astronauts avoid dangerous radiation in space. This is one kind of downpour you don’t want to get caught in, said lead author and undergraduate Max Feinland.

“These particles are the scary ones or what some people call ‘killer electrons,’” said Feinland, who received his bachelor’s degree in aerospace engineering sciences at CU Boulder in spring 2024. “They can penetrate metal on satellites, hit circuit boards and can be carcinogenic if they hit a person in space.”

The study appeared Oct.8 in the journal Nature Communications.

The findings cast an eye toward the radiation belts, which are generated by Earth’s magnetic field. Lauren Blum, a co-author of the paper and assistant professor in the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder, explained that two of these regions encircle our planet: While they move a lot over time, the inner belt tends to begin more than 600 miles above the surface. The outer belt starts roughly around 12,000 miles from Earth. These pool floaties in space trap charged particles streaming toward our planet from the sun, forming a sort of barrier between Earth’s atmosphere and the rest of the solar system.

But they’re not exactly airtight. Scientists, for example, have long known that high-energy electrons can fall toward Earth from the outer radiation belt. Blum and her colleagues, however, are the first to spot a similar rain coming from the inner belt.

Earth and space, in other words, may not be as separate as they look.

“Space weather is really driven both from above and below,” Blum said.

Bolt from the blue

It’s a testament to the power of lightning.

When a lightning bolt flashes in the sky on Earth, that burst of energy may also send radio waves spiraling deep into space. If those waves smack into electrons in the radiation belts, they can jostle them free—a bit like shaking your umbrella to knock the water off. In some cases, such “lightning-induced electron precipitation” can even influence the chemistry of Earth’s atmosphere.

To date, researchers had only collected direct measurements of lower energy, or “colder,” electrons falling from the inner radiation belt.

“Typically, the inner belt is thought to be kind of boring,” Blum said. “It’s stable. It’s always there.”

Her team’s new discovery came about almost by accident. Feinland was analyzing data from NASA’s now-decommissioned Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) satellite when he saw something odd: clumps of what seemed to be high-energy electrons moving through the inner belt.

“I showed Lauren some of my events, and she said, ‘That’s not where these are supposed to be,’” Feinland said. “Some literature suggests that there aren’t any high-energy electrons in the inner belt at all.”

The team decided to dig deeper. 

In all, Feinland counted 45 surges of high-energy electrons in the inner belt from 1996 to 2006. He compared those events to records of lightning strikes in North America. Sure enough, some of the spikes in electrons seemed to happen less than a second after lightning strikes on the ground.

Electron pinball

Here’s what the team thinks is happening: Following a lightning strike, radio waves from Earth kick off a kind of manic pinball game in space. They knock into electrons in the inner belt, which then begin to bounce between Earth’s northern and southern hemispheres—going back and forth in just 0.2 seconds.

And each time the electrons bounce, some of them fall out of the belt and into our atmosphere.

“You have a big blob of electrons that bounces, and then returns and bounces again,” Blum said. “You’ll see this initial signal, and it will decay away.”

Blum isn’t sure how often such events happen. They may occur mostly during periods of high solar activity when the sun spits out a lot of high-energy electrons, stocking the inner belt with these particles.

The researchers want to understand these events better so that they can predict when they may be likely to occur, potentially helping to keep people and electronics in orbit safe.

Feinland, for his part, is grateful for the chance to study these magnificent storms.

“I didn't even realize how much I liked research until I got to do this project,” he said.

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Other co-authors of the new study included Robert Marshall, associate professor in the Ann and H.J. Smead Department of Aerospace Engineering Sciences at CU Boulder, Longzhi Gan of Boston University, Mykhaylo Shumko of the Johns Hopkins University Applied Physics Laboratory and Mark Looper of The Aerospace Corporation.

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Journal

Nature Communications

DOI

10.1038/s41467-024-53036-4 

Article Title

Lightning-induced relativistic electron precipitation from the inner radiation belt

Article Publication Date

8-Oct-2024