Moon Monday #218: A molten Moon, a date for the SPA, sunset for Blue Ghost as well as inclusive Artemis language, and more

There’s a lot in this Moon Monday edition to unpack. Grab yourself a coffee or another mild drug of choice and let’s get started. 🤓

Chang’e 6 samples produce two more big results

Until now, all the direct evidence of our Moon being covered in a global magma ocean shortly after its formation has come from lunar samples brought by Apollo and Luna missions from equatorial and near-equatorial regions on the nearside. Surface measurements made by Chandrayaan 3’s Pragyan rover in 2023 extended this hypothesis’ validity to nearside high-latitude regions. But we had no such tactile measurements from the Moon’s farside until recently. Last year, China’s Chang’e 6 mission brought the first lunar farside samples to Earth, allowing scientists to test if the hypothesis holds true for whole of Luna.

Now, scientists from various institutes in Beijing studying two grams of Chang’e 6 volcanic samples have confirmed the presence of key chemical elements that are compatible with a young fully molten Moon, lending unequivocal credence to the idea. The CNSA release about the study notes that finer deviations in the composition of farside and nearside basalts as revealed by the analysis will help scientists further constrain how our Moon evolved:

The lead isotope evolution paths in basalt from the far and near sides are different. This suggests that different regions of the Moon evolved differently after the magma ocean crystallized. Giant impact events, especially the one that created the SPA Basin, likely changed the physical and chemical properties of the Moon's mantle.

In another critical study published on March 20, scientists from Beijing analyzed five grams of Chang’e 6 samples to determine the truest age yet of the massive South-Pole Aitken (SPA) basin within which the spacecraft landed. Spanning 2500 kilometers, SPA is the Moon’s largest, deepest, and oldest impact crater, and its age and formation nature has huge implications for our Moon’s evolution. Chang’e 6 landed within SPA at 153.99° W, 41.64° S, near the southern rim of the 500-kilometer wide Apollo crater. While the vast majority of Chang’e 6 samples represent much younger volcanic material, the researchers meticulously examined 1600 fragments from those 5 grams to identify 20 pieces that relate to an SPA-like impact-created origin. Precise lead-lead dating of the fragments finds the SPA to have formed 4.25 billion years ago. 💥

The CNSA release about the study notes:

This finding provides the first direct, sample-based evidence that the Moon's largest impact basin formed approximately 320 million years after the beginning of Solar System. The definitive age of 4.25 billion years for the SPA basin can serve as a crucial anchor point for refining the lunar cratering chronology and establishing a more complete temporal sequence of the Moon's early evolution.

With these discoveries, Chang’e 6 is continuing to live up to its bold promises of the mission samples helping scientists solve a whole host of Moon mysteries such as understanding the distinct lunar farside volcanism, determining its age, and learning why the farside is so enigmatically different from the familiar nearside—which is necessary to understand not just Luna’s evolution but that of our Solar System.

I have more coverage of other notable recent results from Chinese lunar missions in the link below:

The Sun sets for Blue Ghost

Capturing a lunar sunset and associated glow on March 16 was one of the final acts of the Blue Ghost Moon lander before US-based Firefly Aerospace sunset the mission part of NASA’s CLPS program—as intended. NASA scientists will study the sunset imagery from multiple cameras as well as surface dust photographed by another instrument SCALPSS during that time to try and determine if electrically charged and levitating dust really is the cause of the lunar horizon glow or not.

In the meanwhile, Firefly has chosen Honeybee Robotics to provide the rover for the company’s third CLPS mission. Honeybee successfully operated instruments on Blue Ghost’s Mission 1. Firefly’s third CLPS flight will carry six NASA-funded science & technology payload suites, including some on the rover, to one of the two Gruithuisen Domes, a unique volcanic site on the Moon’s nearside.

An informative correction: Last week on Moon Monday #217, I wrote that Blue Ghost was the first to capture a solar eclipse from the Moon. I was wrong. The first to do so was NASA’s Surveyor 3 lander on April 24, 1967. It not only photographed the eclipse crown ring but did so on its 114th day on the Moon! Thank you Mark Robinson of the LRO fame for pointing this out. Upon checking the associated paper, a cool fact is that Surveyor 3 used a mirror to bring the Earth in view from its local landed geometry to be able to image the solar eclipse. 🪞✨

Many thanks to Catalyx Space and Gordon Roesler for sponsoring this week’s Moon Monday! If you too appreciate my efforts to bring you this curated community resource for free and without ads, support my independent writing. 🌙

Firefly deserves an unusual kudos

Following China’s lead in successful modern lunar surface missions, and joining Chandrayaan 3 as the only other such mission that went as planned, Firefly has executed a rare, supremely nominal Moon mission with Blue Ghost. Firefly brought the first true soft landing for the US in the 21st century, bounties of knowledge from its science & technology payloads, a precision landing demonstration, the first GPS/GNSS lock on the Moon, a stunning solar eclipse capture, and humble brags despite it all. Immense congratulations are in order to the entire Firefly team, NASA, and all the payload people for pulling this off. 🔥🌗

If you want to learn about how Blue Ghost fits into the larger picture of global lunar exploration, I’ve been covering its lunar activities in context that’s not limited to the US. Follow the four links below for the full rundown:

1. How Firefly approached and achieved a Moon landing in the first attempt with rigor and abundant caution (includes insights from Blue Ghost’s Chief Lander engineer)
2. Blue Ghost achieved third most precise robotic planetary landing
3. A busy lunar morning with lots of payload operations and GPS signals
4. Drilling on the Moon , images of flying regolith, and operating more payloads

NASA removes inclusive language from Artemis

NASA has deleted the following language previously prominently presented on the Artemis landing page on its website:

With the Artemis campaign, NASA will land the first woman and first person of color on the Moon, using innovative technologies to explore more of the lunar surface than ever before.

A previous version of the page hosting said language can be found on the Internet Archive. Eric Berger reported NASA’s response to the change as conveyed via an agency spokesperson:

In keeping with the President’s Executive Order, we’re updating our language regarding plans to send crew to the lunar surface as part of NASA’s Artemis campaign. We look forward to learning more from about the Trump Administration’s plans for our agency and expanding exploration at the Moon and Mars for the benefit of all.

Many are inferring and reporting this as a change of mission crew plans but that’s not the case—not yet anyway. The reasonably diverse Artemis astronaut corps of 18 people hasn’t changed. It incudes women and people of color. Of course, the selection criteria and preference of choosing from within the corps could very well change going ahead given the US-wide inclusion purge.

Related reminder: Critical scientific documents go missing from NASA-backed lunar community website (they’re still missing two months later)

ESA and JAXA move ahead on lunar collaborations

In November 2024, ESA and JAXA announced that the two agencies will keenly examine opportunities for cooperation and collaboration across a whole range of space projects, including lunar exploration. Now they’ve identified various areas across the lunar spectrum to evaluate in detail:

• Coordinating ESA’s upcoming Moonlight constellation and JAXA’s LunaNET test mission for communications and navigation satellites (navcom)
• Payload flight opportunities on missions by both organizations, including upcoming Gateway science by both agencies
• ESA’s existing analog mission testing with LUNA and astronaut training with Pangaea
• Joint studies on future surface missions, particularly how JAXA’s upcoming pressurized habitable rover for Artemis astronauts could work in tandem with ESA’s Argonaut cargo lander  in the 2030s within the Artemis framework.
• Developing technological synergies in power systems, robots, and working on interoperability at system and sub-system levels.

This sounds promising! 🚀

More Moon

ispace Japan is partnering with SpaceData Inc. to build a system which replicates physical elements of the lunar environment such as lunar gravity and communications delays. This will accelerate testing and qualification of Moonbound hardware ahead of real flights. The duo will also build a high-resolution topographical model of the Moon based on data acquired by ispace’s lunar missions.

ESA started operating a similarly driven, expansive LUNA facility since late last year. And, South Korea has developed a full-scale dirty thermovac chamber that accurately simulates the dynamic electrostatic environment on the Moon’s surface. Such facilities also help scientists and engineers understand how to mitigate long-term damage to lunar hardware and astronaut suits from notoriously sticky moondust.

If you like my efforts to bring you Moon Monday every week as a curated community resource compiling and contextualizing all things lunar exploration worldwide for free and without ads, support my independent writing. 🌙