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One of the most iconic events in history is Apollo 11 landing on the lunar surface. During the descent, astronauts Neil Armstrong and Edwin “Buzz” Aldrin are heard relaying commands and data back and forth to mission control across 385,000 kilometers (240,000 miles) of outer space as the lunar module “Eagle” slowly inched its way into the history books.

In the final moments before touchdown, Aldrin can be heard saying, “Picking up some dust”, followed by large dust clouds shooting outward from underneath from the spacecraft as the exhaust plumes interacted with the lunar surface, more commonly known as brownout or brownout effect. This significantly reduced the visibility for Armstrong and Aldrin as they landed, and while they successfully touched down on the Moon, future astronauts might not be so lucky.

Better understanding brownout is exactly what a team of researchers from South Korea examined in a recent study published in Physics of Fluids as they developed a model to help assess safe and practical means to land a human-piloted spacecraft on a planetary surface.

Brownout is important to understand as humanity continues to venture to other worlds. This begins with the upcoming Artemis missions to the Moon, specifically Artemis III, which is slated to land on the lunar surface sometime in 2025. As Armstrong and Aldrin experienced during the Apollo 11 landing, brownout can significantly hinder a pilot’s visibility.

“Understanding the interaction between the rocket plume and the surface is important for the safety and success of space missions in terms of contamination and erosion, landing accuracy, planetary protection, and engineering design, as well as for scientific understanding and future exploration,” said Dr. Byoung Jae Kim, who is an assistant professor in the School of Mechanical Engineering at Chungnam National University, and a co-author on the study.

For the study, the researchers used computer models to simulate landing on the lunar surface and input data about the rocket, rocket engines, surface topography and composition, all in a near-vacuum. The simulation estimated the size and shape of the exhaust plume and the amount of brownout a pilot would see while descending towards the surface in their spacecraft.

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Exhaust plume-surface interaction, more commonly known as brownout, while landing on the Moon, as depicted in Figure 1 of the study. (Credit: Reproduced with permission from A. Rahimi, O. Ejtehadi, K.H. Lee, R.S. Myong, Acta Astronautica, 175 (2020) 308-326. ©2018 Elsevier.)

In the end, the model showed the researchers that brownout effect for both ascent and descent was greater with small regolith particles as they experienced higher altitudes, whereas larger regolith particles with enlarged bed height (thickness) resulted in more desirable brownout conditions.

“The insights gained from this study of the effects of different parameters on plume-surface interaction can inform the development of more effective and efficient landing technologies,” said Dr. Kim. “The study also sheds light on the festooned scour patterns that can be observed on planetary surfaces, which can provide valuable information for future scientific investigations of planetary bodies.”

Aside from landing spacecraft on planetary bodies, the researchers believe their model can be used for other physics-based application, such as needle-free drug delivery systems. Going forward, the researchers plan to incorporate more data into the simulations, such as solid particle collisions and chemical reactions, in hopes of enhancing the model’s capabilities.

While the study focused on a lunar landing, the Moon and Earth aren’t the only places where brownout is experienced, as severe brownout was observed upon NASA’s Perseverance rover landing on Mars in February 2021, and more recently with NASA’s Mars Ingenuity helicopter. As seen in exclusive NASA video, the Perseverance rover became completely enveloped by Martian dust as the sky crane released it upon touchdown, while the brownout created by Ingenuity was observed to be light and short-lived. With Mars being a far dustier place than the Moon, these experiences demonstrate that brownout could pose

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Dear reader,

I love the holidays, partly because I make a point of spending a lot of time outside with family and friends. But it’s also a time when I reflect on how much I enjoy my lifestyle—and how much I appreciate readers like you who follow and support my blog. To show my appreciation, I have a special gift for you.

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Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-guides to classic backpacking trips. Click here to learn how I can help you plan your next trip.

Michael Lanza of The Big Outside above Macon Lake and Washakie Lake on the Washakie Pass Trail in the Wind River Range, Wyoming.
” data-image-caption=”Me above Macon Lake and Washakie Lake on the Washakie Pass Trail in the Wind River Range, Wyoming; and in Death Hollow in southern Utah (lead photo, above).
” data-medium-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?fit=900%2C600&ssl=1″ src=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?resize=900%2C600&ssl=1″ alt=”Michael Lanza of The Big Outside above Macon Lake and Washakie Lake on the Washakie Pass Trail in the Wind River Range, Wyoming.” class=”wp-image-61100″ srcset=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?resize=1024%2C683&ssl=1 1024w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?resize=300%2C200&ssl=1 300w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?resize=768%2C512&ssl=1 768w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?resize=150%2C100&ssl=1 150w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2022/11/Wind9-53-Me-above-Macon-Lake-and-Washakie-Lake-on-the-Washakie-Pass-Trail-in-the-Wind-River-Range-WY.jpg?w=1200&ssl=1 1200w” sizes=”(max-width: 900px) 100vw, 900px” data-recalc-dims=”1″ />Me above Macon Lake and Washakie Lake on the Washakie Pass Trail in the Wind River Range, Wyoming; and in Death Hollow in southern Utah (lead photo, above).

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The Early Universe Had No Problem Making Barred Spiral Galaxies

heic0611b 580x580 1 jpg

Spiral galaxies like the Milky Way are like cosmic snowflakes—no two are exactly alike. For many years, astronomers thought spirals couldn’t exist until the universe was about half its present age. Now, a newly discovered galaxy in the early Universe is challenging that idea.

CEERS-2112 is an early “cosmic snowflake” with spiral arms and a bar across its middle. The amazing thing is that it’s showing this structure when the Universe was only 2 billion years old. That’s about five billion years earlier than astronomers expected something like that to exist. The fact that a perfectly formed spiral exists so early tells us that our ideas about galaxy formation in early cosmic history need some re-tuning.

Surveying the Early Universe

This galaxy showed up in a survey done by the JWST called “Cosmic Evolution Early Release Science” (CEERS). It uses JWST imaging and spectroscopy to do a survey of the early Universe to find the earliest galaxy. The analysis of the CEERS-2112 galaxy was done by an international team led by astronomer Luca Constantin of the Centro de Astrobiología in Spain.

CEERS results should show astronomers the early populations of galaxies at high redshifts (distances). They will also help them estimate related star-formation conditions and black hole growth. Finally, the work should give some insight into the formation of galaxy disks and bulges. Essentially, CEERS data should add to our store of knowledge about first light and reionization (which occurred after the Big Bang) and explain the formation and evolution of early galaxies.

Early deep-field images of very distant galaxies show shreds of galaxies and irregular clumps of stars in the early Universe. That was evident in some of the first Hubble Deep-Field images. The most distant ones in the images looked more blobby and indistinct. And, some of them appeared to be colliding, which fits into the collisional model of galaxy formation.

This view of nearly 10,000 galaxies is called the Hubble Ultra Deep Field. It shows some galaxies in the early Universe, (which appear as red blobs). Credit: NASA/ESA/HUDF
This view of nearly 10,000 galaxies is called the Hubble Ultra Deep Field. It shows some galaxies in the early Universe, (which appear as red blobs). Credit: NASA/ESA/HUDF

Forming Galaxies in the Early Universe

Prior to the Hubble and JWST eras, astronomers really felt that it would take a long time to form spiral galaxies. They often describe a hierarchical model of galaxy formation. That’s where smaller clumpy galaxies collide to form larger ones. Over time, those objects begin to develop structures like spiral arms and bars.

“In such galaxies, bars can form spontaneously due to instabilities in the spiral structure or gravitational effects from a neighboring galaxy,” according to astronomer and team member Alexander de la Vega. He is a post-doctoral researcher currently at the University of California Riverside. “In the past, when the Universe was very young, galaxies were unstable and chaotic. It was thought that bars could not form or last long in galaxies in the early universe.”

The spiral arms are likely the result of density waves moving through the galaxy. The bars also form from density waves radiating out from the center. That compresses material in the arms and bars, leading to bursts of star formation. That could explain why these regions in galaxies seem brighter, with their populations of hot young stars. All of this takes time to accomplish. That’s why astronomers suggested that it would take about half the age of the Universe to form spiral galaxies.

CEERS-2112 is Part of the Early Universe

CEERS-2112 upends the discussion about spiral formation, according to de la Vega. “Finding CEERS-2112 shows that galaxies in the early Universe could be as ordered as the Milky Way,” he said. “This is surprising because galaxies were much more chaotic in the early Universe and very few had similar structures to the Milky Way.”

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Apollo Samples Contain Hydrogen Hurled from the Sun

regolith jpeg

According to the U.S. National Academies of Sciences, Engineering, and Medicine, men should drink 3.7litres of water a day and women 2.7litres. Now imagine a crew of three heading to the Moon for a 3 week trip, that’s something of the order of 189 litres of water, that’s about 189 kilograms! Assuming you have to carry all the water rather than recycle some of it longer trips into space with more people are going to be logistically challenging for water carriage alone. Researchers from the U.S. Naval Research Laboratory (NRL) have discovered lunar rocks with hydrogen in them which, when combined with lunar oxygen provide a possibly supply for future explorers.

A total of 382 kilograms of rock was brought back from the Moon by the Apollo program (I weigh about 80kg so that’s almost five of me in weight – and its all muscle I promise!) Some of the samples were immediately studied while others were sealed for future research hoping that future instrumentation would be more sensitive.

A research team from NRL, led by Katherine D. Burgess and team members Brittany A. Cymes and Rhonda M. Stroud, have recently announced their findings whilst studying some of the lunar rock. They wanted to understand the source of water on the Moon and to understand its formation. Future lunar exploration especially permanent lunar bases will rely heavily upon existing lunar resources. The paper articulates “Effective use of the resource depends on developing an understanding of where and how within the regolith the water is formed and retained”.

Image showing Buzz Aldrin's footprint in the dusty lunar regolith - Credit NASA
Buzz Aldrin’s footprint in the lunar regolith – the soft powdery material found over the surface of the Moon (Credit – NASA)

Transmission electron microscopy was used as part of the study to explore lunar sample 79221. The technique utilises a particle beam of electrons to visualise specimens and generate a highly magnified image. In particular, the team looked at grains of the minerals apatite and merrillite and discovered signs of ‘space’ weathering due to the solar wind. The solar wind is a stream of charged particles that rush outward from the Sun at speeds of up to 1.6 million km per hour!

They found hydrogen signatures in samples in vesicles – small holes left behind after lava cools. The discovery confirms that solar wind is being trapped in detectable quantities proving a potential reservoir that could be accessible to future explorers.

Hydrogen itself is a tremendously useful resource and if that can be mined from the lunar surface material it can aide many aspects of exploration. The real buzz around the discovery is that it may finally resolve the mystery about the origins of lunar water and that it might well be the result of chemical interactions between the solar wind and lunar rocks. If we can understand the origins of the lunar water – and we may finally be close to that now – then we can be sure we use it effectively to reach out further into the Solar System.

Source : Hydrogen detected in lunar samples, points to resource availability for space exploration

The post Apollo Samples Contain Hydrogen Hurled from the Sun appeared first on Universe Today.

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