Space-based artificial solar eclipses could unveil secrets about our Sun
The Moon-Enabled Sun Occultation Mission (MESOM), a groundbreaking space mission spearheaded by the Royal Astronomical Society (RAS) and Durham University, is set to revolutionise our understanding of the Sun's inner workings. This innovative UK-led mission, submitted to the European Space Agency (ESA) in May 2025, aims to create artificial total solar eclipses in space for extended observations of the Sun's elusive corona[1][2][4].
MESOM's key objectives include studying the inner solar corona in unprecedented detail, investigating the physical processes that drive space weather events, and understanding the Sun's magnetic environment[1][2]. To achieve these goals, MESOM employs a suite of advanced instruments, including a high-resolution coronal imager, a corona mass spectrometer, and a spectropolarimeter[1].
The high-resolution coronal imager, provided by the US Naval Research Laboratory, will enable detailed imaging of the corona, while the corona mass spectrometer, developed by Aberystwyth University and the Mullard Space Science Laboratory at University College London (UCL), will analyse the plasma composition and properties[1]. The spectropolarimeter, contributed by the Spanish Space Solar Physics Consortium, will study the Sun's magnetic field and dynamic phenomena like sunspots and flares[1].
MESOM's innovative orbital configuration allows it to align with the Moon's shadow roughly once every 29.6 days, enabling extended observations of the corona for up to 48 minutes at a time—about 10 times longer than Earth-based eclipses[1][2][4]. This unique opportunity will enable MESOM to reach below 1.02 solar radii (710,000 km), allowing it to get 56,000 km closer to the Sun compared to the European Space Agency's existing Proba-3 mission[2].
If selected, MESOM could operate for two years and capture the equivalent of 80 Earth-based eclipses, providing a wealth of data without interference from Earth's atmosphere[1]. The mission, if approved, could launch between 2026 and 2028[1].
The MESOM concept is a collaboration between Mullard Space Science Laboratory UCL (UK), Aberystwyth University, the Surrey Space Centre, University of Surrey, the Naval Research Laboratory (USA), and the Spanish Space Solar Physics Consortium, S3PC, Spain[1]. The mission is based on a feasibility study funded under the UK Space Agency's National Space Technology Programme and a recent UK Space Agency-funded bilateral study[1].
For those interested in learning more about MESOM, a talk titled 'Re-creating total solar eclipses in Space. The Moon-Enabled Sun Occultation Mission concept MESOM' will take place at the National Astronomy Meeting (NAM) on Wednesday 9 July 2025 at 15:35 BST in room TLC101[1].
The Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI), is the UK's largest public funder of research into astronomy and astrophysics, particle and nuclear physics, and space science[3]. The RAS, a UK-based organization founded in 1820 that encourages and promotes the study of astronomy, solar-system science, geophysics, and related branches of science, is also involved in the mission[3].
MESOM represents a novel approach to solar observation, combining celestial mechanics and advanced instrumentation to significantly improve our understanding of the Sun’s corona, its magnetic environment, and drivers of space weather, with potential benefits for both fundamental solar physics and practical forecasting of solar storms[1][2][4].
[1] https://www.mesom.space [2] https://www.ras.ac.uk/discoveries/news/uk-led-space-mission-aims-unravel-solar-mysteries-artificial-eclipses [3] https://stfc.ukri.org/ [4] https://www.dur.ac.uk/
The Moon-Enabled Sun Occultation Mission (MESOM) also highlights the intersection of environmental science, particularly in the study of space weather events, and technology, with its advanced instruments such as the high-resolution coronal imager and the spectropolarimeter playing crucial roles in understanding the Sun's magnetic environment. Additionally, this groundbreaking UK-led mission showcases the collaborative efforts between various institutions in the fields of science and technology, including the Royal Astronomical Society, Durham University, the US Naval Research Laboratory, Aberystwyth University, the Mullard Space Science Laboratory at University College London, and the Spanish Space Solar Physics Consortium.
