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The Martian Residual Crustal Magnetic Fields: A Mitigation Measure Against Space Radiation to Astronauts?

Joshua Anthony22 October 2021

Author: Shiba Rabiee, recent postgraduate student from IRDR, UCL. Shiba.rabiee.20@ucl.ac.uk | Linked In

Mars is approximately half of the size of Earth and is the fourth planet from the Sun. Due to its many similarities with Earth, Mars is argued to be the second most habitable planet in our solar system. The definitive goal has, therefore, always been a human exploration mission on Mars. After decades of research and space agencies working towards this goal, the founder of SpaceX, Elon Musk, announced in an interview that by 2026 they would be able to send astronauts to Mars in cooperation with NASA [1].

However, in deep space astronauts are exposed to dangerous levels of space radiation (i.e. Galactic Cosmic Radiation and Solar Energetic Particles), and Mars is no exception despite its similarities with Earth. In contrast to Earth’s dense atmosphere enabled by its global dipole magnetic field, Mars has residual crustal magnetic fields that cause a very thin atmosphere (~1% of Earth’s) [see Illustration 1] [2, 3]. This creates a highly radioactive and complex environment on Mars that has detrimental, and ultimately lethal, effects for astronaut’s health [3-5].

(Illustration 1. Source: Shiba Rabiee [panel a., created in Microsoft Word]; Kevin M. Gill [panel b., with modifications by Shiba Rabiee]. Cartoon illustrating the global dipole magnetic field of Earth (panel a.) and the residual crustal magnetic fields of Mars (panel b.)).

Throughout the years of sending astronauts into Low Earth Orbit (160-1000 km altitude above Earth), medical doctors and psychiatrists working with astronauts have noticed a decrease in their holistic health when operating a space mission [6, 7]. Space agencies have, therefore, several times encouraged engineers to develop mitigation measures for high radiation exposure but without much success. Shielding measures are essential, yet many issues arise with the creation of shielding such as high financial expense, how to transport the shielding to Mars, and how the material(s) will act in the Martian environment. Space radiation is, therefore, generally acknowledged as a potential barrier for human exploration missions both during Cruise-Phase and whilst on a planet or moon [8].

As space agencies try to create innovative solutions for spacecrafts and crewmembers during Cruise-Phase for a Mars mission, bigger challenges await when arriving on the red planet. A mission to Mars would require astronauts to stay on the planet for several weeks due to the distance between Mars and Earth. In combination with the Martian environment, long-duration space exploration poses several risks and increases the vulnerability to multiple hazards amongst both crewmembers and spacecrafts. Thus, in order to ethically send astronauts to Mars, the radiation problem has to be solved. Research to investigate the mitigation of radiation exposure and associated risks is important to protect good health.

The complexity of creating and transporting affordable mitigation measures has left space agencies with the question of whether to use resources from the Martian environment. A promising mitigation measure currently being discussed is the use of the Martian regolith as a shielding measure by creating a habitat of tunnels beneath the surface of Mars. Yet, this will not provide shielding for astronauts undergoing an extravehicular mission (spacewalk). A human exploration mission will, however, demand exploration of the Martian environment outside the habitat. The need for further investigation and the development of additional mitigation measures, therefore, remains.

The objective of my thesis was to investigate the use of the residual crustal magnetic fields of Mars as a mitigation measure against space radiation exposure during e.g., extravehicular missions. Research on the magnetic fields have been previously conducted [8-16], wherefrom the general argument is that the Martian atmosphere and the magnetic fields provide an equal amount of shielding against space radiation [8] [16]. Yet, these were founded on hypotheses as the Martian atmosphere was not considered during the simulation models [8]. Thus, it was unknown whether the atmosphere could, in fact, provide corresponding shielding measures.

The Martian atmosphere has roughly two orders of magnitude smaller column density than that of Earths and comprises ~95.1% carbon dioxide [16-19]. This, in combination with continuing atmospheric escape, causes the Martian atmosphere to provide almost no shielding against space radiation. Depending on the solar cycle and the chosen location, the estimations conducted for the thesis does, however, imply a potential prolonged extravehicular mission of e.g., ~34 sec/day to ~74 min/day within a field strength of 14 nT [see magnetic fields strength map for the range of field strengths measured at 400 km altitude]. These estimates will increase with increasing field strengths, thus, indicating that the residual crustal magnetic fields can be used as a mitigation measure. Moreover, the estimates imply a significant difference between shielding provided by the atmosphere and the residual crustal magnetic fields.

(Illustration 2. Source: Shiba Rabiee. Data source: Planetary Geologic Mapping Program; The Planetary Data System; the ArcGIS ESRI geodatabase. Map presenting the residual crustal magnetic field strengths measured by Mars Global Surveyor at 400 km altitude).

This conclusion is founded on methods and various assumptions. To confirm the results presented, further investigation of the residual crustal magnetic fields needs to be completed. Suggestions for potential future missions and research has, therefore, additionally been presented and discussed in the thesis.

Mars has been argued to have looked very similar to Earth ~3.8 billion years ago [see Illustration 3] [20]. Further investigations of the residual crustal magnetic fields of Mars will not only enable an understanding of its potential to act as a shielding measure, but similarly to Mars, atmospheric escape can also be found on Earth. Yet, despite long investigations of Earth’s atmospheric escape many questions remain unanswered. A comprehensive investigation of the residual crustal magnetic fields and its relation to the Martian environment could, therefore, inform about the core of Mars and the planets atmospheric escape, consequently enabling an understanding of the atmospheric leakage on Earth. Research in this area may provide essential information of what could be the future of Earth.

(Illustration 3. Source: Kevin M. Gill [modifications by Shiba Rabiee]. Depiction of the evolution of Mars from ~3.8 billion years ago (left) to the Martian environment today (right)).

Shiba Rabiee is a recent postgraduate student from IRDR, UCL. Email at Shiba.rabiee.20@ucl.ac.uk| Linked In


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[17] Jakosky, B.M.; Slipski, M.; Benna, M.; Mahaffy, P.; Elrod, M.; Yelle, R.; Stone, S.; Alsaeed, N. (2017): Mars’ atmospheric history derived from upper-atmosphere measurements of 38Ar/36Ar. Science. Volume 355, Issue 6332. DOI: 10.1126/science.aai7721. pp. 1408-1410.

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[19] Nier, A.O.; McElroy, M.B. (1977): Composition and Structure of Mars’ Upper Atmosphere: Results From the Neutral Mass Spectrometers on Viking 1 and 2. AGU. Journal of Geophysical Research. Volume 82, Issue 28. DOI: https://doi.org/10.1029/JS082i028p04341. pp. 4341-4349.

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Illustrations and Map

Gill, Kevin M. [modified by Shiba Rabiee] (2015): Mars. Flickr. https://www.flickr.com/photos/53460575@N03/16716283421 [Accessed 13.10.2021].

ArcGIS: ESRI geodatabase – ESTRI_ASTRO. https://www.arcgis.com/home/user.html?user=esri_astro [Accessed: 10.05.2021].

NASA: Planetary Data System. https://pds-ppi.igpp.ucla.edu/search/?t=Mars&facet=TARGET_NAME [Accessed: 27.05.2021].

USGS; NASA: The Planetary Geologic Mapping Program. https://planetarymapping.wr.usgs.gov [Accessed: 04.05.2021].

Gill, Kevin M. [modified by Shiba Rabiee] (2015): Evolution of Mars. Flickr. https://www.flickr.com/photos/53460575@N03/17234143751 [Accessed 14.10.2021].

Are Rohingyas protected in countries that did not sign the 1951 refugee convention?

Bayes Ahmed5 October 2021

Rohingyas are a predominantly Muslim minority from the Rakhine State (former Arakan) of Myanmar (former Burma). Since they are not recognised as citizens by the Myanmar authority, Rohingyas have faced widespread discrimination forcing more than one million of them to flee their country since 1970. The United Nations (UN) labelled the Rohingyas as the “world’s most persecuted minority“. In August 2017, killings, rape, torture and other massive human rights violations resulted in ethnic cleansing, which forcibly displaced Rohingyas, mainly to South and Southeast Asian countries. The case is currently under investigation by the International Criminal Court (ICC) and the International Court of Justice (ICJ) (The Gambia v. Myanmar on violations of the Convention against Genocide)

In September 2021, over 900,000 Rohingyas were registered with United Nations High Commissioner for Refugees (UNHCR) and living in camps in Cox’s Bazar, Bangladesh. There were also some Rohingyas living in Saudi Arabia, India and Malaysia. However, the exact numbers of displaced Rohingyas worldwide are uncertain since many are not registered with the United Nations High Commissioner for Refugees (UNHCR). Moreover, none of these host countries is signatories of the Convention Relating to the Status of Refugees (1951) nor have national asylum legislations. Consequently, the Rohingya – stateless people who enter these countries mostly undocumented – are classified as irregular migrants under their migration legislation. In this blog post, we discuss how Rohingyas are protected in these countries, considering the role of  UNHCR and new developments in the global asylum regime with the Global Compact on Refugees (GCR) and the Global Refugee Forum (GRF) framework. The military coup in Myanmar on February 01, 2021, may initiate a new influx of Rohingya (and other) refugees to these host countries and prevent future possibilities of their safe and voluntary return to Myanmar.

UNHCR and the protection of Rohingyas in national cases

Bangladesh is the country most affected by the latest Rohingya exodus. The country shelters Rohingya refugees in camps in Cox’s Bazar in south-eastern Bangladesh. UNHCR, together with other UN agencies, international non-governmental organisations (NGO) and local organisations, have provided relief and services to this refugee population. While the Government of Bangladesh has recognised Rohingyas as prima facie refugees in previous influxes like 1991-1992, Rohingyas that entered the country after 2017 are classified as Forcibly Displaced Myanmar Nationals (FDMN). Bangladesh is granting physical protection for Rohingyas. They have access to medical care, shelter, education, food and essential supplies. However, Rohingyas have no right to work and free movement inside Bangladesh. The right to higher education is also limited in the camps. The support to the Rohingya population is highly dependent on international aid, which makes the current situation in Bangladesh unsustainable in the long term. The ongoing pandemic could also affect the funding to the Rohingya response in Bangladesh. 

In Saudi Arabia, India, and Malaysia, UNHCR registers refugees and conducts refugee status determination following its mandate to identify people in need of international protection. UNHCR identification cards allow refugees to stay in these countries, which prevents the risk of refoulement. However, being recognised as refugees by UNHCR does not grant them access to fundamental rights available to nationals such as education, healthcare, work and free movement. UNHCR Help webpage of Saudi Arabia recalls that “Registering with UNHCR, even if recognised as a refugee, does not give the applicant any special status […] Registration with UNHCR does not mean the applicant will have the right to public healthcare, education, and employment“. In some countries, such as India, refugee children between 6 and 14 years old have access to education. All refugees have access to healthcare. In Malaysia, Rohingya children cannot access the local educational system because UNHCR refugee cards are not recognised as identification documents. Refugees pay higher fees than nationals to access healthcare but have a discount of 50% because of a partnership with UNHCR

UNHCR registered refugees have access to UNHCR services (e.g., learning centres in Malaysia) and partnerships. However, they are not legally allowed to work in any of these countries. Unlike the situation in Bangladesh, most Rohingya refugees are not in refugee camps and in receipt of aid to meet their basic needs in these countries. They have to work to survive, and they do so in the same way as irregular migrants. This situation puts them at risk of detention and even deportation. There were cases of detention of Rohingyas in Malaysia, Saudi Arabia, and India. 

Since these countries are not part of the 1951 Refugee Convention, they can adopt ad hoc approaches in recognising some groups of people based on their national interests. For example, Saudi Arabia granted residency to Rohingya refugees who arrived before 2011. However, those that arrived after that faced detention and are considered irregular migrants. This approach of providing protection and rights to some groups or nationalities put the Rohingyas in an unstable situation. Furthermore, agreements with the UNHCR and the current approach of protection may change at any time depending on the political will of the national governments, which may result in forced return and refoulement of Rohingyas to Myanmar.

These countries do not recognise local integration as a durable solution to the Rohingya refugees. Host governments fear that granting rights would allow refugees’ local integration and could attract more Rohingyas to their territories. Besides that, some of these host countries are categorised as least developed or developing countries facing internal struggles such as persistent poverty, illiteracy and inequality. Bangladesh – the country sheltering most Rohingya refugees globally (> 95%) – is the least-developed country facing environmental, economic and social challenges. Bangladesh does not have the means to guarantee local integration as a sustainable solution for hundreds of thousands of Rohingyas living in one of its poorest regions. Resettlement is an option only for Rohingyas registered with UNHCR in Malaysia.

Nevertheless, the number of refugees worldwide and Rohingyas in need of protection in a third country is larger than the resettlement quotas of receiving countries. Consequently, the Rohingyas’ host countries advocate returning to Myanmar as the only possible solution for this population. While this is also the preferable solution for Rohingyas, they wish to return to a place where their safety and rights will be guaranteed. Rohingyas need to be recognised as citizens by the Myanmar government and have access to rights, safety and security. Perpetrators of crimes against Rohingyas need to be held accountable too. Other human right treaties (Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment in the case of Bangladesh and Saudi Arabia, and International Covenant on Civil and Political Rights in the case of Bangladesh and India) forbid host governments to return Rohingyas to a place where they may be subjected to torture or cruel, inhuman or degrading treatment or punishment.

Protection of Rohingya refugees and new multilateral developments on Asylum

On December 17, 2018, the Global Compact on Refugees (GCR) was approved after a process of two years of consultations with different stakeholders (states, NGOs, individuals) coordinated by the UNHCR. As this organisation recalls, the GCR is a non-binding framework that does not substitute for the 1951 Refugee Convention and its protocol but builds on them to foster responsibility-sharing and international cooperation. Some Rohingya host countries like Bangladesh, India, and Saudi Arabia provided written contributions to draft this document. Although the GCR is not mandatory and does not mention specifically the situation of Rohingyas, it is an important protection tool for refugees in general with a clear mechanism of regular revisions that considers the situation of stateless people and discusses possibilities of international and regional cooperation to address forced displacement and durable solutions. 

Besides that, the GCR created the framework for the organisation of the Global Refugee Forum in 2019 when states, organisations, universities and individuals presented voluntary pledges and contributions regarding forced displacement worldwide. The pledges directed to the Rohingya situation involve: guaranteeing protection, safe childhoods and child-sensitive services with no discrimination (education, child protection, healthcare, and mental health and psychosocial support) for Rohingya children and host communities’ children; empowering refugee children through sports in Cox’s Bazar, Bangladesh; providing funding to UNHCR to respond to the Rohingya crisis; creating a working group on education involving actors in Cox’s Bazar, Bangladesh and Rakhine, Myanmar; expanding livelihood opportunities and empowerment for Rohingyas and host communities; improving the environment for Rohingyas including psychological support; granting funding to playful learning for refugee children; providing support to survivors of sexual violence; implementing a joint approach with the World Bank and the Government of Bangladesh to support refugees and host communities medical, nutritional and educational needs; advocating child-rights based solutions and the inclusion of refugees in national educational systems. 

Bangladesh presented one pledge to design innovative refugee solutions. India presented two pledges: committing to build capacities of states – including beyond neighbourhood (e.g., Africa) and reaffirming its commitment to building solutions together. Malaysia also submitted one pledge to promote the objectives of the GCR and the 2030 Agenda. Saudi Arabia pledged $1 million to implement the GCR on Yemen. Moreover, other States in the world did not present any specific pledges about Rohingya refugees to fulfil the GCR’ objectives of “easing the pressures on host countries” and “expanding access to third-country solutions”.

While these actions are essential for the immediate protection of Rohingya refugees, they do not guarantee the long-term protection of this population (against refoulement or forced return as previously discussed) or durable solutions. Besides that, the central host countries of the Rohingyas presented only broad pledges regarding the implementation of the GCR with no specific guarantee of rights or protection to Rohingya refugees. None of the host countries presented any pledges to become parts of the 1951 Refugee Convention and its protocol or create national asylum systems to protect refugees.


Rohingya refugees are physically protected in non-signatory countries that are not currently returning them to Myanmar. Nevertheless, while Rohingyas may be recognised as refugees under the UNHCR mandate, they are treated as irregular migrants. At the same time, host countries perceive their return as the only possible solution, and their agreements with UNHCR may change according to their national interests, which put Rohingyas at risk of unsustainable repatriation. Besides that, while host countries were part of the Global Compact on Refugees, host countries did not present specific pledges on protecting the Rohingya population. Considering this, we propose two primary recommendations to protect the Rohingyas:

  1. The protection of Rohingya refugees is a responsibility of the international community and not only the host countries. The international community should pressure Myanmar to stop persecuting this minority and guarantee their safe and voluntary return as their preferable durable solution.
  2. If their safe and voluntary return is not possible (especially considering the February 2021 coup in Myanmar), the international community should follow the principle of responsibility sharing and implement other solutions to Rohingyas, such as the design of specific resettlement programs for this population and the adoption of complementary pathways for admission to third countries as described in the GCR including family reunification, humanitarian visas and corridors, educational opportunities and private and community-based sponsorship programmes.


Patrícia Nabuco Martuscelli, Social Science Research Fellow in Conflict and Migration, Institute for Risk and Disaster Reduction, University College London (UCL).

* Bayes Ahmed, Lecturer in Risk and Disaster Science, Institute for Risk and Disaster Reduction, University College London (UCL); Corresponding author: bayes.ahmed@ucl.ac.uk

Peter Sammonds, Director, Institute for Risk and Disaster Reduction, University College London (UCL).

** The reflections are part of the “Resilient Futures for the Rohingya Refugees” and “Rohingya Journeys of Violence and Resilience in Bangladesh and its Neighbours” projects developed at the Institute for Risk and Disaster Reduction, University College London (UCL). We thank the funding of the Royal Society (Royal Society Award Reference: CHL\R1\180288) and the British Academy (British Academy Award Reference: SDP2\100094).