Space and Physics
PUBLISHED
In its dying moments, the Blue Ghost lunar lander captured the first high-definition images of a sunset on the Moon. The lunar nightfall differs subtly from an Earthly sunset, and the images could help unravel a long-standing mystery surrounding an unusual haze first observed on the Moon in the 1960s.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Firefly Aerospace, a Texas-based private company, successfully landed Blue Ghost in the Mare Crisium region of the Moon on March 2, with support from a NASA-funded initiative. The mission had two weeks to carry out 10 experiments and objectives – all of which were completed – before this part of the Moon entered the lunar night.
During these 14 days of darkness, when a specific region of the Moon is not exposed to sunlight, temperatures can plunge to -133°C (-208°F) near the equator and even lower at the poles, making survival nearly impossible for most equipment.
On March 16, sunset arrived and ultimately spelled the end of this historic mission. However, this final event did allow Blue Ghost to capture some incredible footage of the Sun dropping towards the horizon and the Moon plummeting into darkness.
“These images, captured by different camera angles and stitched together in a video, show a horizon glow that comes to life just above the Moon’s surface as the sun goes down. Earth and Venus (further in the distance) are also shown above the Moon,” Firefly wrote on its live update blog.
The images could provide clues to explain lunar horizon glow, a phenomenon where dust particles in the Moon's thin atmosphere create a glow during lunar sunset. First documented in the 1960s by the robotic spacecraft Surveyor 5, 6, and 7, it was believed to result from light scattering through a cloud of dust particles. Now, with this new high-definition image, fresh insights may emerge.
"One of the things they will be looking for in some of the imagery is to see if they can identify a phenomenon called 'horizon glow' or a mechanism called 'dust lofting,'” Joel Kearns, deputy associate administrator for exploration at NASA's Science Mission Directorate, said at a media conference.
“Lunar dust particles can become charged due to exposure to solar ultraviolet radiation. These particles can experience what we think is electrostatic repulsion, causing them to lift off the lunar surface,” he added.
“It is going to take some time to go through these images, but what I'm really happy about is that these images, I think they're the first high-definition images looking at sunset and transitioning into the dark,” noted Kearns.
