NASA Reveals its Planetary Science Goals for Artemis III

If all goes well, NASA’s Artemis III mission will bring humans back to the Moon as early as 2026, the first time since the Apollo 17 crew departed in 1972. It won’t be a vacation, though, as astronauts have an enormous amount of science to do, especially in lunar geology. A team from NASA recently presented their planetary science goals and objectives for Artemis III surface activities, which will guide the fieldwork the astronauts will carry out on the lunar surface.

The Artemis III Geology Team presented their priorities at the Lunar and Planetary Science Conference in March 2024. In addition, NASA also announced their choices for the first science instruments that astronauts will deploy on the surface of the Moon during Artemis III.

The landing site hasn’t been chosen yet, but it will be within 6 degrees of latitude from the South Pole. These instruments will collect valuable scientific data about the lunar environment, the lunar interior, and how to sustain a long-duration human presence on the Moon, which will help prepare NASA to send astronauts to Mars.

“Artemis marks a bold new era of exploration, where human presence amplifies scientific discovery. With these innovative instruments stationed on the Moon’s surface, we’re embarking on a transformative journey that will kick-start the ability to conduct human-machine teaming – an entirely new way of doing science,” said NASA Deputy Administrator Pam Melroy. “These three deployed instruments were chosen to begin scientific investigations that will address key Moon to Mars science objectives.”

Two of the three main Artemis science goals and the instruments deal with understanding the Moon itself. The Lunar Environment Monitoring Station (LEMS) is a compact, autonomous seismometer suite will help study planetary processes, while the Lunar Dielectric Analyzer (LDA) will aid in understanding the character and origin of lunar polar volatiles. The third main science objective will investigate how to mitigate the risks of human exploration, and to that end the Lunar Effects on Agricultural Flora (LEAF) instrument will investigate the lunar surface environment’s effects on space crops to see if the lunar regolith can be used to grow food.  

Falling under the planetary science goals with the two instruments, scientists have laid out four main objectives, which are designed to be “site agnostic,” so that they can be performed at any landing site, or be able to be modified to fit with any future chosen landing site.

• A. Understand the Early Evolution of the Moon as a Model for Rocky Planet Evolution

The main objective here is to evaluate the leading theory of the Moon’s early days, which is the Lunar Magma Ocean (LMO) theory. It is theorized that a layer of molten rock was present on the surface of the Moon from the time of the Moon’s formation (about 4.5 or 4.4 billion years ago) to tens or hundreds of millions of years after that time, which led to the formation of the crust, mantle, and core. While the LMO model is supported by many observations, it is not supported by all.

The scientists said gathering samples from the Moon’s polar region and comparing the ages and chemical and isotopic compositions of the new samples to those collected by the Apollo astronauts will help to evaluate the current LMO model and perhaps “find alternate or more complex LMO models.” Scientists would also like to determine the composition of the lower crust, and mantle materials if possible.

Another theory that scientists hope to put under scrutiny during the Artemis program is the giant impact hypothesis. This is the most widely accepted theory for the origin of the Earth–Moon system, which proposes the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon. However, similarities between the Earth and Moon don’t quite fit that model, the majority of the Moon’s material should originate from the impactor. “The Artemis III samples will allow new assessments of the formation process and age of the Moon,” the scientists wrote.

• B. Determine the Lunar Record of Inner Solar System Impact History.

Impacts played a big role in the early history of our Solar System, and scientists say they would like to determine the age of South Pole Aitken (SPA) Basin, the oldest known lunar impact basin. “This will provide key new information for determining when the record of bombardment starts and how complete that early record is,” the scientists wrote. They also hope to determine the sources of early impactors, which will provide a fundamental benchmark for understanding the ages of surfaces across the Solar System.

Scientists would also like to gather data to test the Lunar Cataclysm Hypothesis, a theory that says an intense period of bombardment occurred on the Moon about 3.9 billion years ago, where about 80% of the Moon was “resurfaced,” with the formation of approximately 1,700 craters 100 kilometers in size or larger.  This hypothesis is controversial, but determining if this period of bombardment did occur would help scientists determine if a similar cataclysmic bombardment may have affected life on Earth or been involved in life’s origins.

For the two above goals, the Lunar Environment Monitoring Station (LEMS) will carry out continuous, long-term monitoring of the seismic environment, namely ground motion from moonquakes, in the lunar south polar region. This instrument is expected to operate for at least three months and up to two years and may become a key station in a future global lunar geophysical network. NASA said the instrument will characterize the regional structure of the Moon’s crust and mantle, providing valuable information to analyze the current lunar formation and evolution models.

• C & D: Determine the Variability of Regolith in the Circumpolar Environment as a Keystone for Understanding Surface Modification of Airless Bodies, and Reveal the Age, Origin, and Evolution of Solar System Volatiles

The Moon’s poles – and especially the permanently shadowed regions – have been compared to an attic in an old house, because it likely contains a record of history. On the Moon, the “attic-like” regions near the poles would still hold the exogenous material delivered to the inner Solar System. Since the terrestrial record of the early Earth is largely lost, finding it on the Moon would be extremely valuable.  

“Little is known about cold-trapped volatile composition, abundance, age, and the general ability of the Moon to retain volatiles over time,” the scientists wrote. “….Assessing volatiles in cold traps of varying thermal environments and age will provide key new observations to understand their nature.”

And there’s also growing evidence for the presence of lunar polar volatiles like water, hydrogen, and methane, which would be extremely important for future long-term habitation on the Moon. Scientists also want to study how volatiles might be transported across the lunar surface, as such transport has yet to be measured on the Moon, and how it might occur – whether it driven by diurnal temperature changes, solar wind or and micrometeoroid delivery across the Moon.

The Lunar Dielectric Analyzer (LDA) will help in these studies as it will measure the regolith’s ability to propagate an electric field, which is a key parameter in the search for lunar volatiles, especially ice. It will gather essential information about the structure of the Moon’s subsurface, monitor dielectric changes caused by the changing angle of the Sun as the Moon rotates, and look for possible frost formation or ice deposits.

“These three scientific instruments will be our first opportunity since Apollo to leverage the unique capabilities of human explorers to conduct transformative lunar science,” said Joel Kearns, deputy associate administrator for exploration in NASA’s Science Mission Directorate in Washington. “These payloads mark our first steps toward implementing the recommendations for the high-priority science outlined in the Artemis III Science Definition Team report.”

With the Artemis program, NASA will land the first woman, first person of color, and its first international partner astronaut on the Moon, and with the goal of establishing long-term exploration for scientific discovery and preparation for human missions to Mars for the benefit of all.

For more details, you can read the Planetary Science Goals and Objectives for Artemis III Surface Activities document here, and the Artemis III Science Definition Team Report.