A groundbreaking new mission under NASA’s Artemis programme is set to offer unprecedented insights
into Earth’s magnetosphere, the invisible shield protecting our planet from harmful solar radiation. The Lunar Environment Heliospheric X-ray Imager (LEXI) will soon capture the first-ever global images of this magnetic field,
revealing how it responds to space weather and cosmic forces. This revolutionary mission is a collaboration between NASA and Firefly Aerospace, launching as part of the Commercial Lunar Payload Services (CLPS) initiative. With liftoff planned from Kennedy Space Center in Florida no earlier than mid-January,
the mission promises to shed light on one of Earth’s mostcritical natural defences.
Understanding Earth’s magnetosphere from the Moon is key to this mission. The magnetosphere is Earth’s protective bubble, deflecting most of the Sun’s charged particles and shielding the planet from harmful solar wind. LEXI, installed aboard Firefly Aerospace’s Blue Ghost Lander, will turn its gaze back toward Earth shortly after landing on the lunar
surface. Over six days, the instrument will collect low-energy X-ray images from the magnetopause – the outer boundary of Earth’s magnetosphere. These images will offer
a global perspective of how the magnetosphere expands, contracts, and interacts with solar winds. By capturing this big picture, researchers aim to understand how Earth’s magnetosphere responds to space weather events, such as solar storms,
and the processes allowing streams of solar particles to penetrate Earth’s defences.
One of the central phenomena LEXI will observe is the magnetosphere’s rhythmic expansion and contraction, akin to breathing. When solar wind intensifies, the magnetosphere compresses and shifts closer to Earth; as it subsides, the field expands outward. LEXI’s vantage point on the Moon provides
an unobstructed view of these dynamics, enabling unprecedented detail capture.
Another fascinating aspect is magnetic reconnection, where magnetic field lines from the magnetosphere merge with those from the solar wind. This process releases bursts of energy, driving auroras and creating energetic particles capable of affecting satellites and power grids. LEXI’s observations will help answer questions about whether magnetic reconnection occurs steadily or sporadically and whether multiple sites can form concurrently. According to Brian Walsh, LEXI’s principal investigator, "We’re trying to get this big picture of Earth’s space environment."
The practical outcomes of this research are significant. By deepening our knowledge of the magnetosphere’s behaviour, scientists can improve predictions of space weather events, which is pivotal for safeguarding satellites, power grids, and communication networks. Solar storms, albeit creating brilliant auroras, present risks to technology, amplifying the importance of LEXI’s findings for modern society’s resilience.
The story of LEXI’s creation is as fascinating as its mission. Originally developed as STORM for detecting low-energy X-rays, the instrument was initially launched on a sounding rocket back in 2012, and after its test flight, it was placed on display at NASA’s Goddard Space Flight Center.
When NASA put out the call for CLPS projects, Walsh and his team refurbished STORM, replacing outdated components to rejuvenate its purpose. "We’d break the glass - not literally - but remove it, restore it, and refurbish it," Walsh explained. This effort bridged the gap, allowing scientists to obtain the global picture of Earth’s magnetosphere they’ve long sought.
Lastly, LEXI exemplifies NASA's commitment to advancing space exploration and technology through innovative partnerships. The mission’s success will not only enrich scientific knowledge but also play a significant role
in the Artemis program, enhancing our grasp of Earth’s place within the cosmos and its environmental systems.