• Photo by Nicolas J Leclercq on Unsplash
  • Photo by Nicolas Tissot on Unsplash
  • Photo by NASA on Unsplash
  • Photo by USGS on Unsplash

A new view of lunar magnetism

One of the enduring mysteries about the Moon is whether it ever had an internal-generated magnetic field, and if so, when the core dynamo ceased. New research by Tinghong Zhou, John Tarduno, Rory Cottrell, and Eric Blackman at the University of Rochester and collaborators from the University of Notre Dame, UC Santa Cruz, and the University of Arizona, in a study supported by NSF and NASA, have provided new insights into this lunar puzzle, narrowing down the potential lifespan of the Moon’s dynamo to its first ~140 million years. The new study focused on analyzing magnetic field intensity (called paleointensity) recorded in Apollo samples that are between 4.36 to 3.7 billion years old. Using an advanced technique known as single-crystal paleointensity analysis, the researchers were able to obtain accurate measurements of the Moon’s ancient ambient surface magnetic field environment – which indicated negligible field strengths. This evidence for the absence of a dynamo resolves the long-lasting paradox between the previously hypothesized long-lived lunar dynamo and energy considerations, namely that the tiny lunar core would have been unable to power a strong, sustained magnetic field.

Figure 1: Astronaut John Young stands on the rim of the Plum Crater on the Moon. Image source: NASA, Apollo Lunar Surface Journal, Apollo Image Library Hasselblad Magazine, 109/G (B&W), AS16-109-17804.

A key part of this new understanding of lunar magnetic history comes from a focus on magnetic carriers meeting the demanding requirements of paleointensity theory. Single-domain magnetic grains, which are very small, some 20 to 200 nm in size, are required. In contrast, larger magnetic grains are far less reliable because their internal domain walls can move with time and during laboratory treatments, corrupting any original magnetic signal. Magnetic minerals in lunar rocks are dominated by these problematic multidomain grains, making paleointensity analysis very challenging. The single-crystal paleointensity technique used in the study by Zhou and others builds on an earlier study led by the University of Rochester and focuses on silicate crystals that contain single-domain magnetic grain inclusions to meet the paleointensity recording requirement. The authors tested the fidelity of their records by CO2 laser heating in different fields and in the presence or absence of an applied field. These tests exclude thermal alteration and provide a measure of recording efficiency. The authors found high recording efficiencies, indicating that if surface fields had been present, they would have been recorded. Hence, the absence of a paleointensity indicates absence of a surface field.

In addition to the single crystal paleointensity, the study also employed whole rock paleointensity on 3.7-billion-year-old Apollo basalts using a non-thermal technique. Unlike thermal methods that measure magnetization acquired from natural cooling, non-thermal methods rely on additional assumptions and empirical calibrations. The results from the non-thermal technique showed abnormally high and inconsistent paleointensities. These anomalies could indicate shock magnetization from lunar impacts or issues with the multidomain grains and/or the applied non-thermal method. Because non-thermal analysis of whole rocks is the basis for some calls for an episodic lunar dynamo, the researchers conclude there is no robust evidence for such a phenomenon from Apollo samples.

Figure 2: Lunar magnetic history indicated by paleointensity data. Single crystals suggest a null lunar magnetic field since 4.36 Ga, while some whole rock data obtained by non-thermal methods yield abnormally high values that might be related to large multidomain magnetic grains and/or impact induced magnetic field. Figure modified from Tarduno et al., 2021 and Zhou et al., 2024.

If the Moon did not have a dynamo for most of its history, the early Earth’s (for example, during the Archean and Hadean eons) atmosphere can be transferred to the Moon, which would be unshielded by an intrinsic field, and preserved in its regolith. With a smaller Earth-Moon distance and the stronger solar wind in the Archean and Hadean, this transfer would have been enhanced. By studying the volatiles trapped in the lunar regolith, we might have opportunities to better understand the composition of the early Earth’s atmosphere and the conditions that influenced the evolution of life.



Tinghong Zhou is a postdoctoral researcher at the University of Rochester mentored by Professor John A. Tarduno. Her research focuses on the long-term evolution of the geomagnetic field and its correlation with the Earth’s deep interior, and the origin of the lunar magnetism. Email address: tzhou16@ur.rochester.edu

IAGA Sponsorship for Meetings

IAGA provides sponsorship for people interested in organising meetings under its remit, especially for students, early career researchers or scientists in developing countries. The funding can be used for various purposes such as registration fee waiver or enabling participation of participants who otherwise wouldn't be able to travel by supporting their travel/accommodation costs. There are two rounds of applications open- end of May and November- each year with outcomes aimed for June and December, respectively.

The ideal time for submitting funding request is a year before the event, with details of the meeting such as venue, dates and scientific focus. The submission is made to the Secretary General and is evaluated by the Executive Committee. The funding capacity may differ for different years but in general, the maximum amount is about 3000 EUR.

More details can be found here. Please feel free to leave your queries in the comments below and we will answer them.

IAGA 2025 Abstract Submission Closing!

The International Association of Geomagnetism and Aeronomy (IAGA) will have a joint conference with the International Association of Seismology and Physics of the Earth's Interior (IASPEI) this year from 31st August to 5th September in Lisbon, Portugal. It will be preceded by a week long summer school organised by the two associations for early career researchers in their respective fields. 

The abstracts submission as well as travel grant applications are closing soon on 12th March 2025 while the early bird registration deadline is 21st May 2025. More details about abstract submission, registration and the conference can be found on the website. The abstract and travel grant notifications will be sent out by 17th April 2025. Abstract title and text are limited to 20 and 250 words respectively.

All information, new and old will be regularly posted on our blog page including many outreach sessions planned. Stay tuned for more info to start preparing for the upcoming conference! You can see the list of blogs related to the assembly by visiting this webpage.

IUGG ECSNet Project

The IUGG ECSNet (Early Career Scientists Network) project awarded to Katia Pinheiro aims to bring together the 8 associations under IUGG through early career involvement. The project has an ECS representative from each association and organises a 'How to get involved' Day which can provide more information. The first event was held on 3rd February 2025 and the next event will be on 3rd March. We hope you take this chance to know more about the associations and participate in it! Below is the 'How to get involved' pamphlet for IAGA.



IAGA Data and Products

IAGA has a database of products and services that are free and available to use for all scientists requiring it. Here are some of the latest links/updates on them which might be useful to the community-

IGRF: A very well known model that is updated every 5 years. The 14th model is now available, the details of which can be found in our previous blog.

INTERMAGNET: All your magnetic ground observatories list and its data can be accessed here. It also offers software tools most often used within the community.

ISGI: Database and updates on the various indices used in geomagnetism. It contains the list of magnetic events that can be extracted from the data available at INTERMAGNET.

PALEOMAGIA: database of Precambrian paleomagnetic data. Its website recently got updated which can be found on clicking the link.

MagIC: Magnetic Information Consortium which is an open digital data archive primarily for rock and paleomagnetic data.

There are several other databases and products, the details of which can be found on the IAGA website or here.


Publish your Geoscience Outreach

Do you work on outreach in Geosciences and are interested in publishing your work?


Frontiers is accepting submissions for their research topic 'Bridging Geoscience and Society: Enhancing Community Awareness and Involvement' and the manuscript summary deadline is April 30th 2025! The topic aims to explore critical themes that bridge scientific knowledge with community impact and emphasise the significance of natural hazards. The role of science outreach in promoting public awareness and engagement is vital and this initiative hopes to showcase that.

This approach seeks to enhance understanding and appreciation of Earth sciences, facilitating meaningful dialogue between researchers and the public. It aims to foster interest in geosciences by linking scientific research with the general public, ultimately contributing to a more informed society. 

Several article formats are accepted and the fees can be covered by the institutions that have partnered with Frontiers. For any questions, please feel free to visit the links or email or leave your questions in the comments below! Some of our IAGA ICEO members are involved in the project and they would be happy to clear your doubts.

Results of survey on conference expectations

A thorough understanding of attendees and their specific needs is crucial for designing conferences that are both relevant and effective. Thus, in summer 2024, we conducted a survey on researchers’ perceptions of and expectations towards scientific conferences. The survey was also distributed to the IAGA community, and you might have participated in it. Thank you very much for your contribution!

Survey participants considered scientific conferences useful and important. In particular, participants expected to explore research objectives and network at their next planned conference. Participants’ expectations of what to gain at their next planned conference largely did not differ between conference formats. The only exception were participants’ networking expectations, as virtual participants had lower expectations to network than in-person participants (Figure 1). Based on this, it can be argued that differences between in-person conferences and alternative formats become marginal once virtual and hybrid conferences can enable effective networking.

Figure 1. Participants expectations of what to gain at conferences. The variables were measured on a Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). Dots represent means and error bars represent 95% confidence intervals. The five factors were measured with three to six items. Significant differences between in-person and virtual participants are marked with a *.


Participants’ conference expectations differed based on individual characteristics, such as career stage, geographical context, and personal circumstances, revealing that not all researchers need the same of conferences. Networking was the only factor that all participants expected to benefit from, highlighting that this is universally valued across all researchers and career stages.

Early-career researchers had higher expectations regarding acquiring general information, career development and securing scientific follow-up opportunities compared to senior researchers. Simultaneously, researchers from the Global South had higher expectations to acquire general information, explore research objectives and secure scientific follow-up opportunities compared to their researchers from the Global North. Furthermore, disadvantaged researchers (defined as those facing challenges with visa restrictions, childcare responsibilities, funding, and disabilities) had higher expectations for acquiring general information, career development and securing scientific follow-up opportunities compared to more privileged researchers. This highlights that researchers who are typically underrepresented and disadvantaged in traditional in-person conferences often stand to benefit the most from attending, as they pursue outcomes that go beyond networking.

Overall, the results highlight the potential of virtual and hybrid conference formats to meet the diverse expectations of researchers while significantly reducing travel-related greenhouse gas emissions and enhancing inclusivity by removing barriers like funding and visa restrictions. Virtual and hybrid formats can currently effectively address many conference objectives, except for networking, which requires innovative tools to support informal exchanges. To transition toward sustainable practices, conference organizers should define clear goals, adopt purpose-driven formats, and invest in advanced technologies that cater to diverse researcher needs. These changes can align conferences with environmental and social sustainability goals while addressing the evolving needs of the global research community.

Annex

The results of the survey will be published in a research article that is currently under review. Supplementary Table 1 provides a description of the survey sample, while Supplementary Table 2 presents regression results analysing differences in researchers’ expectations based on individual characteristics.

Supplementary Table 1. Sample description of the 820 participants working in academia and research

Variable

 

Percentage

Career stage

 

 

 

 

Scientific field

 

 

 

 

Employment continent

 

 

 

 

 

Nationality

(by continents)

Undergraduate / master’s student

Doctoral / PhD student

Postdoc / early-career researcher 

Professor / scientific group leader > 10 years

Retired researcher

Natural sciences

Engineering and technology

Medical and health sciences

Humanities and arts

Social sciences

Asia

Africa

Europe

North America

South America

Oceania

Asia

Africa

Europe

North America

South America

Oceania

1.34%

26.46%

26.34%

36.34%

1.83%

35.37%

7.32%

5.00%

6.83%

44.02%

5.24%

3.78%

66.22%

17.20%

1.46%

4.76%

7.80%

4.15%

60.61%

17.32%

4.15%

3.78%


Supplementary Table 2. Linear regression model explaining the five dependent factors for the in-person participants (N = 776)

Independent variables

Networking

Acquiring general information

Exploring research objectives

 

 

β

SE

t

p

β

SE

t

p

β

SE

t

p

Intercept

5.764

.151

38.245

< .001

4.701

.198

23.746

< .001

5.807

.134

43.331

< .001

 

 

 

 

 

 

 

 

 

 

 

 

 

Career stage

(0: ECR, 1: Seniors)

.068

.067

1.007

.314

-.659

.088

-7.447

< .001

.037

.060

.614

.539

 

 

 

 

 

 

 

 

 

 

 

 

 

Scientific field

(0: Non-STEM, 1: STEM)

-.072

.068

-1.061

.289

.276

.089

3.109

.002

.129

.060

2.141

.033

 

 

 

 

 

 

 

 

 

 

 

 

 

Employment continent

(0: Global South, 1: North)

-.052

.111

-.468

.640

-.631

.145

-4.348

< .001

-2.37

.098

-2.424

.016

 

 

 

 

 

 

 

 

 

 

 

 

 

Gender

(0: Female, 1: Male)

-.076

.067

-1.133

.258

-.118

.088

-1.334

.183

-.099

.060

-1.656

.098

 

 

 

 

 

 

 

 

 

 

 

 

 

Fieldwork involvement

(0: No, 1: Yes)

.142

.068

2.084

.038

.244

.089

2.729

.007

.075

.060

1.232

.218

 

 

 

 

 

 

 

 

 

 

 

 

 

Disadvantaged status

(0: No, 1: Yes)

.006

.079

.075

.940

.420

.103

4.071

< .001

.122

.070

1.743

.082

 

 

 

 

 

 

 

 

 

 

 

 

 

Conference scale

(0: Continental,

1: Intercontinental)

.117

.067

.075

.940

.055

.088

.619

.536

.306

.060

5.122

< .001

 

 

 

 

 

 

 

 

 

 

 

 

 

Regression Model

F(7,641) = 2.00, p = .053,

R2 adjusted = .02

F(7,641) = 17.16, p < 0.001,

R2 adjusted = .15

F(7,641) = 6.82, p < 0.001,

R2 adjusted = .06

 

Independent variables

Career development

Securing scientific follow-up opportunities

 

 

β

SE

t

p

β

SE

t

p

 

Intercept

5.631

.187

30.171

< .001

4.068

.185

21.936

< .001

 

 

 

 

 

 

 

 

 

 

 

Career stage

(0: ECR, 1: Seniors)

-.477

.083

-5.720

< .001

-.195

.083

-2.357

.019

 

 

 

 

 

 

 

 

 

 

 

Scientific field

(0: Non-STEM, 1: STEM)

-.013

.084

-.158

.874

.331

.083

3.977

< .001

 

 

 

 

 

 

 

 

 

 

 

Employment continent

(0: Global South, 1: Global North)

-.267

.137

-2.948

.052

-.703

.136

-5.172

< .001

 

 

 

 

 

 

 

 

 

 

 

Gender

(0: Female, 1: Male)

-.173

.083

-2.081

.038

.049

.083

.592

.554

 

 

 

 

 

 

 

 

 

 

 

Fieldwork involvement

(0: No, 1: Yes)

-.103

.084

-1.222

.222

.244

.084

2.919

.004

 

 

 

 

 

 

 

 

 

 

 

Disadvantaged status

(0: No, 1: Yes)

.355

.097

3.652

< .001

.318

.097

3.288

.001

 

 

 

 

 

 

 

 

 

 

 

Conference scale

(0: Continental, 1: Intercontinental)

.107

.083

1.292

.197

.223

.083

2.695

.007

 

 

 

 

 

 

 

 

 

 

 

Regression Model

F(7,641) = 8.58, p < 0.001, 

R2 adjusted = .08

F(7,641) = 11.88, p < 0.001, 

R2 adjusted = .11

 

 


The survey is conducted by Ariane Wenger, a doctoral student at the Transdisciplinarity Lab (TdLab), Department of Environmental Systems Sciences (D-USYS), ETH Zurich, Switzerland. In case of questions or comments, feel free to contact her via e-mail: ariane.wenger@usys.ethz.ch.