50 years after NASA’s Apollo mission, moon rocks still have secrets to reveal

How did we get from stardust to the place we’re as we speak? That is the query NASA scientist Andrew Needham has contemplated his whole profession.

In 1969, astronauts of Apollo 11 have been the primary to set foot on the moon and to check the lunar floor. Over the subsequent a number of Apollo missions, ending in 1972, they introduced again moon rocks for scientific analysis to unlock mysteries of the universe.

Scientists knew the rocks contained clues to the origins of the solar system in addition to minerals that may very well be of curiosity for advancing space journey past the moon. However again then, in-depth evaluation was hindered due to a low stock of rock samples and a scarcity of superior analysis expertise.

Now, practically 50 years later, Needham is learning those self same rocks with characterization instruments and strategies light-years forward of their predecessors. One such approach is neutron scattering.

On the Division of Vitality’s Excessive Flux Isotope Reactor, or HFIR—situated at Oak Ridge Nationwide Laboratory—Needham studied a small assortment of lunar and asteroid samples utilizing the newly renamed neutron imaging instrument MARS, quick for the Multimodal Superior Radiography Station. On the time of the experiments, Needham labored for Jacobs because the contractor part supervisor for Astromaterials Curation at NASA’s Johnson Area Heart in Houston.

Like X-rays, neutrons are used to look inside supplies to establish and measure components and their atomic association. Neutrons may also present insights into how supplies may be harnessed to enhance expertise. In Needham’s case, he is utilizing them to check the mineral content material inside Apollo samples and meteorites, looking for clues to early planetary formations and the place water may be saved on the moon.

“Previously decade, there’s actually been a renewed curiosity in on the lookout for water in locations just like the moon,” he mentioned. “We used to suppose the moon was very dry, however now we all know that water is trapped contained in the mineral content material of those rocks. Research have proven that water may be accumulating close to the poles of the moon by means of affect occasions which can be evidenced in these samples.

“If people are going to additional discover the moon, and one day Mars, we have to determine methods to gas ourselves and survive past Earth, as a substitute of regularly supplying the whole lot from the Earth’s floor, which could be very tough and really, very costly.

“Understanding the composition of those rocks, the place hydrogen atoms are, how they’re saved and transported, actually helps us perceive the moon over its historical past and as much as its current day, and the way we’d use that data to journey even additional.”

The Apollo mission samples Needham is learning embody affect breccias, that are made up of dust, rock fragments and melted particulates combined collectively after meteorites are pulled into gravity wells and bombard the moon’s floor. Needham defined that when the meteorites struck roughly 4 billion years in the past, the impacts mixed with and stirred up mixtures of supplies from the moon’s floor in addition to its deeper inside layers. In essence, he mentioned, even one moon rock can comprise a plethora of data from a number of astronomical occasions.

Neutrons are ideally suited to learning the chemical composition of the Apollo moon rocks: They’ll move by means of nearly any materials, however mild components corresponding to hydrogen will block or deflect them upon contact.

Utilizing the MARS instrument, which focuses on creating radiographic photographs much like scientific X-rays, Needham loaded the samples into containers stationed on a rotating platform that permits measurements to be taken of the rocks in 360 levels. Areas the place hydrogen atoms are prone to be discovered are highlighted throughout the rocks because the neutron beam passes by means of the pattern.

Within the neutron photographs, the hydrogen atoms present up as brightly coloured spots in distinction to the remainder of the pattern. The tougher it’s for a neutron to move by means of a component, the brighter that aspect will seem, making a shade scale that corresponds to completely different components. The 360-degree measurements can then be used to create 3D fashions of the rocks that may in flip be in contrast with outcomes from different analysis strategies, corresponding to X-rays and electron microscopy.

Extra neutron measurements of the moon rocks have been taken at HFIR’s sister facility, the Spallation Neutron Supply, or SNS, which is powered by the world-leading 1.55 megawatt pulsed-beam accelerator. The SNAP instrument at SNS focuses on learning supplies below excessive pressures, however it additionally at the moment serves as a testbed for VENUS, a brand new state-of-the-art imaging instrument at SNS that may end building in 2024. Collectively, MARS and VENUS will present researchers with the world’s most full set of imaging capabilities supplied at one establishment.

“These are valuable samples, so we won’t go slicing and dicing as a lot as we wish,” mentioned Needham. “Neutrons assist us see contained in the samples in order that we will take advantage of exact slices to show solely the areas of curiosity. And it is actually solely neutron imaging that makes hydrogen atoms visually come out, letting you realize that, ‘Ooh! That is one thing I need to take a look at.'”

A month after conducting his experiments on the MARS instrument, Needham began a brand new place: analysis scientist at NASA Goddard Area Flight Heart because the contamination management scientist for the company’s Artemis program. Artemis represents the subsequent step in human space exploration. Its purpose is to ascertain a sustainable presence on the moon as a step towards sending the primary astronauts to Mars.

“Apollo solely landed in a number of choose areas of the moon,” Needham mentioned. “The Artemis missions are going to be bringing again samples from many alternative areas, samples which can be prone to be wealthy in hydrogen and different vital minerals. A part of my job will probably be to make sure these samples are as completely preserved as doable for future analysis, similar to the scientists who had the foresight 50 years to do the identical for the samples that we’re learning as we speak.

“The types of analyses out there at Oak Ridge will probably be actually vital for Artemis. It is a part of a long-term plan to deliver next-generation strategies to the subsequent technology of samples that we will be bringing again.”