SPACE/COSMOS
Molten Martian core could explain red planet’s magnetic quirks
University of Texas at Austin
image:
Computer simulation of a one-sided magnetic field on early Mars based on data from a study led by the University of Texas Institute for Geophysics. The study could explain the unusual magnetic imprint found on Mars today.
view moreCredit: Ankit Barik/Johns Hopkins University
Like Earth, Mars once had a strong magnetic field that shielded its thick atmosphere from the solar wind. But now only the magnetic imprint remains. What’s long baffled scientists, though, is why this imprint appears most strongly in the southern half of the Red Planet.
A new study from the University of Texas Institute for Geophysics (UTIG) could help explain the one-sided imprint. It presents evidence that the planet’s magnetic field covered only its southern half.
The resulting lopsided magnetic field would match the imprint we see today, said the study’s lead author Chi Yan, a UTIG research associate at the UT Jackson School of Geosciences. It would also make Mars’ magnetic field different from Earth’s, which covers the entire globe.
Yan said that the one-sided magnetic field could arise if Mars’ inner core was liquid.
“The logic here is that with no solid inner core, it’s much easier to produce hemispheric (one-sided) magnetic fields,” Yan said. “That could have implications for Mars’ ancient dynamo and possibly how long it was able to sustain an atmosphere.”
In the study, published in the journal Geophysical Research Letters, the researchers used a computer simulation to model this scenario.
Until now, most studies of early Mars had relied on magnetic field models that gave the Red Planet an Earth-like inner core that’s solid and surrounded by molten iron.
The researchers were inspired to try simulating a fully liquid core after NASA’s InSight lander found that Mars’ core was made of lighter elements than expected. That means the core’s melting temperature is different from Earth’s and therefore quite possibly molten, said study co-author Sabine Stanley, a Bloomberg Distinguished Professor at Johns Hopkins University.
If Mars’ core is molten now, it almost certainly would have been molten 4 billion years ago when Mars’ magnetic field is known to have been active, Stanley said.
To test the idea, the researchers prepared simulations of early Mars with a liquid core and ran them a dozen times on supercomputers. With each run the researchers made the planet’s northern half of the mantle a little hotter than the south.
Eventually, the temperature difference between the hotter mantle in the north and the cooler mantle in the south led to the heat escaping from the core to be released only at the southern end of the planet. Channeled in such a way, the escaping heat was sufficiently vigorous to drive a dynamo and generate a strong magnetic field focused in the southern hemisphere.
A planetary dynamo is a self-sustaining mechanism that generates a magnetic field, typically through movement in the molten metallic core.
“We had no idea if it was going to explain the magnetic field, so it's exciting to see that we can create a (single) hemispheric magnetic field with an interior structure that matches what InSight told us Mars' interior is like today,” Stanley said.
According to UTIG planetary researcher Doug Hemingway, the finding offers a compelling alternative theory to a common assumption that involves asteroid impacts obliterating evidence of a planet-wide magnetic field in northern hemisphere rocks.
“Mars is naturally interesting to look at because it's like Earth in some ways and it’s the closest planet that we can imagine actually setting up shop on,” said Hemingway, who was not part of the study. “But then, it’s got this dramatic hemispheric dichotomy where the topography, the terrain and the magnetic field of the northern hemisphere and southern hemisphere are dramatically different. Anything that gives a clue at what could account for some of that asymmetry is valuable.”
The study was funded by the NASA InSight program. The simulations were conducted at the Maryland Advanced Research Computing Center.
Journal
Geophysical Research Letters
Method of Research
Computational simulation/modeling
Subject of Research
Not applicable
Article Title
Mars' Hemispheric Magnetic Field From a Full-Sphere Dynamo
An illustration of NASA's InSight spacecraft. The lander’s instruments found that Mars may have a fully molten core. That could explain Mars’ one-sided magnetic field according to research by the University of Texas Institute for Geophysics.
Credit
NASA/JPL-Caltech
How flexible wearables protect astronauts' health in space
image:
Fig. 1. The effects of microgravity on an astronaut's musculoskeletal system.
view moreCredit: Yi Wang, et al.
A review published recently in Wearable Electronics examines the current applications and persistent challenges of flexible wearable technologies in aerospace medicine. As human space exploration progresses toward extended-duration missions, the imperative for real-time monitoring of astronauts' physiological and psychological well-being has become increasingly critical. The unique space environment characterized by microgravity conditions, cumulative radiation exposure, and extreme thermal fluctuations presents multifaceted health risks to crew members.
Flexible wearable systems, equipped with multimodal sensor arrays, enable comprehensive and continuous health surveillance. These integrated platforms include inertial measurement units, biosignal electrodes, and environmental detectors, among others. They have proven to be indispensable for early anomaly detection in cardiopulmonary functions, neuromuscular performance, and circadian rhythm regulation, thereby facilitating timely personalized countermeasures.
Nonetheless, despite recent advancements in materials science and miniaturized electronics, three notable technical barriers persist: 1) device reliability under combined space stressors, 2) secure data management protocols addressing confined spacecraft privacy concerns, and 3) multi-parametric data fusion challenges involving temporal-spatial synchronization of heterogeneous bio-signals.
Breakthrough development trajectories emphasize future research in the field of flexible wearable devices, particularly for astronaut applications, will focus on several key areas and their interdisciplinary collaborations. These research areas will cover advanced materials science, new materials and sensor technology, intelligent algorithms, data processing and device integration. Interestingly, the development of technologies in the field will still rely on material innovation, the creation of intelligent algorithms, the improvement of user experience and interdisciplinary cooperation. In particular, continuous development and maturity of the technology, together with flexible electronic devices, will play an important role in enhancing astronauts' health monitoring capabilities and promoting the progress of human space exploration in the future.
Fig. 2. Integrated smart wearables with advanced features
Credit
Yi Wang, et al.
Fig. 3. To develop more advanced astronaut health monitoring devices in the future, interdisciplinary collaborations are needed, including but not limited to new materials and sensor technology, intelligent algorithms and data processing as well as device integration.
Credit
Yi Wang, et al.
Contact the author: Yi Wang, Corresponding author at: Department of Physical Education, Renmin University of China, Beijing 100872, China., wyi@bsu.edu.cn
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Journal
Wearable Electronics
Method of Research
Systematic review
Subject of Research
Not applicable
Article Title
Flexible wearable device applications for monitoring astronaut health: Current status and challenges
Scientists may have solved a puzzling space rock mystery
Carbon-rich asteroids are abundant in space yet make up less than 5 per cent of meteorites found on Earth. An international team of scientists scoured the globe to find an answer
Curtin University
An international team of researchers may have answered one of space science’s long-running questions – and it could change our understanding of how life began.
Carbon-rich asteroids are abundant in space yet make up less than 5 per cent of meteorites found on Earth.
An international team of scientists from Curtin University’s School of Earth and Planetary Sciences, the International Centre for Radio Astronomy (ICRAR), the Paris Observatory and more scoured the globe to find an answer.
Published today in Nature Astronomy, researchers analysed close to 8500 meteoroids and meteorite impacts, using data from 19 fireball observation networks across 39 countries — making it the most comprehensive study of its kind.
Co-author Dr Hadrien Devillepoix from Curtin’s Space Science and Technology Centre and Curtin Institute of Radio Astronomy (CIRA) said the team discovered Earth’s atmosphere and the Sun act like giant filters, destroying fragile, carbon-rich (carbonaceous) meteoroids before they reach the ground.
“We’ve long suspected weak, carbonaceous material doesn’t survive atmospheric entry,” Dr Devillepoix said.
“What this research shows is many of these meteoroids don’t even make it that far: they break apart from being heated repeatedly as they pass close to the Sun.
“The ones that do survive getting cooked in space are more likely to also make it through Earth’s atmosphere.”
Carbonaceous meteorites are particularly important because they contain water and organic molecules — key ingredients linked to the origin of life on Earth.
Paris Observatory’s Dr Patrick Shober said the findings reshape how scientists interpret meteorites collected so far.
“Carbon-rich meteorites are some of the most chemically primitive materials we can study — they contain water, organic molecules and even amino acids,” Dr Shober said.
“However, we have so few of them in our meteorite collections that we risk having an incomplete picture of what’s actually out there in space and how the building blocks of life arrived on Earth.
“Understanding what gets filtered out and why is key to reconstructing our solar system’s history and the conditions that made life possible.”
The study also found meteoroids created by tidal disruptions — when asteroids break apart from close encounters with planets — are especially fragile and almost never survive atmospheric entry.
“This finding could influence future asteroid missions, impact hazard assessments and even theories on how Earth got its water and organic compounds to allow life to begin,” Dr Shober said.
Other institutions involved in the study were the Astronomical Institute of the Romanian Academy, National Museum of National History and Aix-Marseilles University.
The study was supported by funding from the International Centre for Radio Astronomy Research.
Perihelion history and atmospheric survival as primary drivers of the Earth’s meteorite record was published in Nature Astronomy.
Journal
Nature Astronomy
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
Perihelion history and atmospheric survival as primary drivers of the Earth’s meteorite record
Article Publication Date
14-Apr-2025
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