Mesom: Moon-enabled Sun Occultation Mission Could Revolutionize Space Weather Forecasting

Moon-enabled Sun Occultation Mission (Mesom) would use the Moon as a natural occulting disk to observe the Sun’s corona with unprecedented detail, aiming to boost space weather forecasting and mitigate Carrington-like disruptions. The article outlines the concept, recent solar-storm activity, and the limitations of ground-based eclipses and existing coronagraphs, such as LASCO and Proba-3. Led by Mullard Space Science Laboratory at UCL and UK Space Agency-backed teams with international partners, Mesom envisions monthly observation windows up to 48 minutes during a two-year nominal mission, with a potential launch in the 2030s. Author: The Conversation

Introduction: Space Weather and the Need for Better Forecasts

When powerful solar storms strike Earth, they disrupt technology we rely on daily, from GPS to power grids. The article highlights how magnetic fields and energetic particles from the Sun interact with Earth's magnetosphere, a phenomenon categorized as space weather. It notes recent intense solar activity and the lessons learned from past events, such as the Carrington Event and more recent CME-driven disturbances that affected satellites and infrastructure.

"Space weather forecasting is essential for protecting Earth’s increasingly technology-dependent society" - The Conversation

Mesom: A Mission to Recreate Space Eclipses

The core of the article centers on Mesom, a Moon-enabled Sun Occultation Mission designed to recreate total solar eclipse conditions in space. This approach would allow researchers to study the Sun’s corona in greater detail across timescales and wavelengths, providing new data on how magnetic fields confine and release hot plasma.

"Mesom aims to create total solar eclipses in space, allowing detailed views of the Sun's atmosphere" - The Conversation

Technical Context: Coronagraphy, Eclipses, and Past Missions

The piece reviews traditional coronagraphy, including ground-based occulting masks and space telescopes like LASCO on SoHO, and mentions Proba-3’s formation-flying concept. It discusses the enduring challenges—artifacts, atmospheric distortion, and limited near-surface viewing—that have limited current measurements of the deepest solar layers. The Mesom concept seeks to overcome these by leveraging lunar occultation to prolong high-quality corona observations.

"Ground-based eclipses are limited by weather and atmospheric distortions; space-based eclipses could overcome these limits" - The Conversation

Celestial Occulters and International Collaboration

The article describes the Moon as a natural occulting disk, due to its near-perfect sphericity and lack of thick atmosphere, making it an ideal in-space eclipse mask. It traces the Mesom development through the Surrey Space Centre's investigations and the international consortium led by UCL’s Mullard Space Science Laboratory, with partners across Spain, the US, and Australia. The plan foresees annual, month-long observation windows with substantial data return, significantly more than Earth-based eclipses.

"The Moon provides a near-perfect occulting disk for prolonged corona measurements" - The Conversation

Outlook: Feasibility, Timelines, and Impact

With UK Space Agency funding and ESA consideration, Mesom is positioned as a potential 2030s mission, offering at least 400 minutes of high-resolution, low-altitude coronal data over a two-year period. The article emphasizes the mission’s transformative potential for solar physics and space-weather forecasting, highlighting its advantage over centuries of Earth-based eclipse opportunities.

"Mesom could unlock decades of corona data in a single lifetime, something Earth-bound eclipses cannot match" - The Conversation