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SGU Celebrates 1000 Episodes; A Skeptical Retrospective: Global Warming, Solar Panels, Cold and Hot Fusion, Medical Quackery, UFOs; Science or Fiction

Meanwhile, in Dobrzyn, Hili is not an unreliable narrator:

Hili: I’m a responsible editor.
A: Why are you saying this?
Hili: So that there are no doubts.

Hili: Jestem redaktorem odpowiedzialnym.
Ja: Dlaczego to mówisz?
Hili: Żeby nie było wątpliwości.

Where would be the most ideal landing site for the Artemis III crew in SpaceX’s Human Landing System (HLS)? This is what a recent study submitted to Acta Astronautica hopes to address as an international team of scientists investigated plausible landing sites within the lunar south pole region, which comes after NASA selected 13 candidate landing regions in August 2022 and holds the potential to enable new methods in determining landing sites for future missions, as well.

Here, Universe Today discusses this research with Dr. Juan Miguel Sánchez-Lozano from the Technical University of Cartagena and Dr. Eloy Peña-Asensio from the Politecnico di Milano regarding the motivation behind the study, significant findings, the reasons for determining the final landing site, location to Shackleton Crater, and if a lander smaller than HLS would have changed the outcome? Therefore, what was the motivation behind the study?

Dr. Sánchez-Lozano tells Universe Today, “Our motivation was to contribute to the selection process for the Artemis III landing site by introducing methods that are well-established in other fields of study to the context of space exploration for the first time. Specifically, we identified that Geographic Information Systems combined with Multi-Criteria Decision-Making (GIS-MCDM) methodologies could provide significant value in evaluating and prioritizing the candidate landing sites. Therefore, we aimed to demonstrate the utility of these methods to NASA and apply them in practice by identifying and recommending the most suitable landing locations.”

For the study, the researchers used these methods to analyze 1,247 locations within the 13 candidate landing regions near the lunar south pole previously identified by NASA to ascertain the most precise landing sites for HLS. They accomplished this by combining their GIS-MCDM methodologies with a Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) algorithm to analyze specific criteria: lunar surface visibility, line of sight for HLS astronauts, Permanently Shadows Regions (PSRs), sunlight exposure, direct communication with Earth, geological units, and abundance of mafic (volcanic rock high in iron or magnesium) materials. Therefore, what were the most significant findings from this study?

Dr. Peña-Asensio tells Universe Today, “In addition to demonstrating the applicability of MCDM to these challenges, our analysis identified Site DM2 (Nobile Rim 2) as the optimal landing site based on criteria such as visibility, solar illumination, direct communication with Earth, geological diversity, and the presence of mafic materials. The best nine locations identified in our study are all situated within this region. Surprisingly, this site is not among the most favored regions within the scientific community.”

Site DM2 is one of the furthest landing regions within the 13 candidate landing regions, located approximately 250 kilometers (150 miles) from Shackleton Crater, the latter of which has a portion located directly on the lunar south pole. The researchers identified the exact location of the optimal landing site being 84°12’5.61” S and 60°41’59.61” E, which is located near a PSR crater. The reason PSR craters are of exploration importance is due to the craters being so deep that no sunlight has reached their depths in possibly billions of years, potentially resulting in their potential housing of water ice deposits. Therefore, what were the specific reasons for selecting Site DM2 and what are some potential backup landing sites?

Dr. Sánchez-Lozano tells Universe Today, “Site DM2 offers exceptional performance across several key criteria, including the highest percentage of solar illumination, optimal proportions of explorable ice-hosting areas, and extended communication windows with Earth. The strength of the decision-making methodology we employed, particularly the TOPSIS technique, lies in its compensatory nature. This approach allows criteria with merely acceptable values to be offset by others with excellent values, resulting in a comprehensive ranking of alternatives. Consequently, adjacent landing sites to the optimal location may also present highly viable options with a high degree of acceptability.”

Regarding back sites, Dr. Peña-Asensio tells Universe Today, “As potential backup sites, we consider DM1 (Amundsen Rim) particularly compelling, as it offers locations with consistently high averages across all evaluated parameters. We also highlight Site 004, centered at the edge of the Shackleton Crater, which our analysis identifies as one of the best landing sites.”

As noted, one of the primary criteria for determining the most optimal landing site is HLS, which will attempt to land the first humans on the lunar surface for the first time since Apollo 17 in 1972. However, the height of HLS is almost ten times greater than the Apollo lander at 50 meters (160 feet) and 5.5 meters (17.9 feet), respectively, which means landing a larger spacecraft carries its own benefits and challenges.

For context, the original spacecraft design for Apollo called for landing a large spacecraft on the lunar surface known as direct ascent, which Wernher von Braun was initially in favor of using. However, the direct ascent technique was scrapped in favor of the Lunar Orbit Rendezvous (LOR) technique, which argued to be less risky due to a smaller spacecraft needing to land on the lunar surface. Therefore, if a smaller lander than HLS (i.e., Apollo-sized) was being used, how would this influence the landing site selection?

Dr. Peña-Asensio tells Universe Today, “This would directly impact our results, as we considered criteria such as the lander’s solar illumination received for energy recharging, visibility from the lander windows to help astronaut extravehicular activities and to allow intravehicular science, and direct communication with Earth. A lower lander could intensify the challenges posed by local topography, obstructing sight lines and the sunlight. However, it might also offer increased stability for the lander (by reducing its center of mass height), potentially decreasing the terrain slope safety restrictions and thereby opening up new landing site options for exploration.”  

As landing sites for the Artemis III mission continue to be debated, NASA is currently scheduled to launch Artemis II late next year with a four-person crew whose mission will be to orbit the Moon and return to the Earth like Apollo 8 in December 1968. Additionally, the commercial space industry is taking their own shots at landing near the lunar south pole with the upcoming IM-2 mission courtesy of Intuitive Machines, which earlier this year successfully landed the first American spacecraft on the Moon for the first time since 1972.

This study demonstrates that a plethora of methods can be used to determine optimal landing sites for the Artemis missions and potentially other missions to other planetary bodies throughout the solar system, specifically the use of mapping and machine learning algorithms. Therefore, as we approach the Artemis III mission and the first human landing since Apollo 17, these methods will continue to evolve and improve to develop enhanced landing methods as humanity continues its journey into the cosmos.

Dr. Sánchez-Lozano tells Universe Today, “This research demonstrates how methodologies from the field of engineering projects and the business world, such as multi-criteria decision-making techniques, can be applied to solve decision problems of interest to the international astronomical community, such as the proposed case study: the selection of the optimal landing site for the Artemis III mission.”

Where will Artemis III ultimately land near the lunar south pole and how will landing site selection methods improve in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Artemis III Landing Sites Identified Using Mapping and Algorithm Techniques appeared first on Universe Today.

Scientists have identified and demonstrated a method to process a plant-based material called nanocellulose that reduced energy needs by a whopping 21%, using simulations on the lab's supercomputers and follow-on analysis.

Physicists directly observed ultracold atoms in an 'edge state,' flowing along a boundary without resistance. The research could help physicists manipulate electrons to flow without friction in materials that could enable super-efficient transmission of energy and data.

What is the shortest route to the next stop or the agreed meeting point? Global positioning systems (GPS) have become a routine part of everyday life for most people. Until now, however, the minimum number of GPS satellites needed to determine the exact position of a mobile phone or other navigation device has remained a matter of conjecture. Researchers have now proved that a precise location can be determined in most cases with five or more satellites. At present, we can generally be sure of having contact to only four satellites.

What is the shortest route to the next stop or the agreed meeting point? Global positioning systems (GPS) have become a routine part of everyday life for most people. Until now, however, the minimum number of GPS satellites needed to determine the exact position of a mobile phone or other navigation device has remained a matter of conjecture. Researchers have now proved that a precise location can be determined in most cases with five or more satellites. At present, we can generally be sure of having contact to only four satellites.

Few scientists doubt that Mars was once warm and wet. The evidence for a warm, watery past keeps accumulating, and even healthy skepticism can’t dismiss it. All this evidence begs the next question: what happened to it?

Mars bears the marks of a past when water flowed freely across its surface. There are clear river channels, lakes, and even shorelines. NASA’s Perseverance rover is working its way around Jezero Crater, an ancient paleolake, and finding minerals that can only form in water’s presence. MSL Curiosity has found the same in Gale Crater.

The water that created these landscape features is gone now. Some of it has retreated to the polar caps, where it remains frozen. But aside from that, there are only two places where the remainder of Mars’ ancient water could’ve gone: underground or into space.

Scientists think that there’s water under Mars’ surface. In 2018, researchers found evidence of a large subglacial lake about 1.5 km beneath the southern polar region, though these results have been met with some skepticism. Even if the lake is real, there’s nowhere near enough water there to account for all of Mars’ lost water.

In new research in Science Advances, a team of scientists using data from the Hubble Space Telescope and NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter explain how Mars lost much of its water to space. The research is “Martian atmospheric hydrogen and deuterium: Seasonal changes and paradigm for escape to space.” The lead author is John Clarke, a Professor of Astronomy and the Director of the Center for Space Physics at Boston University.

“Overall, the results presented here offer strong supporting evidence for a warm and wet period with an abundance of water on early Mars and a large amount of water loss into space over the lifetime of the planet.”

John Clarke, Director, Center for Space Physics at Boston University.

“There are only two places water can go. It can freeze into the ground, or the water molecule can break into atoms, and the atoms can escape from the top of the atmosphere into space,” explained Clarke in a press release. “To understand how much water there was and what happened to it, we need to understand how the atoms escape into space.”

The research focuses on two types of hydrogen: what we can call ‘regular’ hydrogen (H) and deuterium (D). Deuterium is hydrogen with a neutron in its nucleus. Water is H2O—two hydrogen atoms bonded to one oxygen atom—and water molecules can contain either hydrogen or deuterium. The neutron contributes additional mass and makes deuterium twice as heavy as hydrogen.

Ultraviolet light from the Sun can split water molecules apart into their constituent hydrogen and oxygen atoms. In an escape-to-space scenario, more of the heavier deuterium is likely to be left behind than hydrogen.

As time passed on Mars and hydrogen kept escaping into space, more of the heavier deuterium was left behind. Over time, this preferential retention shifted the ratio of hydrogen to deuterium in the atmosphere. In this research, Clarke and his co-researchers used MAVEN to see how both atoms escape from Mars currently.

NASA launched MAVEN in 2013, and it reached Martian orbit in 2014. Since then, the capable spacecraft has been observing the Martian atmosphere, making it the first spacecraft dedicated to the task. Its overarching goal is to determine how Mars lost its atmosphere. One of its specific goals is to measure the rate of gas loss from the planet’s upper atmosphere to space and what factors and mechanisms govern the loss.

NASA’s MAVEN spacecraft is depicted in orbit around an artistic rendition of planet Mars, which is shown in transition from its ancient, water-covered past to the cold, dry, dusty world that it has become today. Credit: NASA

MAVEN’s instrument suite contains eight powerful instruments. However, every mission has its tradeoffs, and where MAVEN is concerned, it’s unable to monitor deuterium emissions throughout the entire Martian year. Mars’s orbit is more elliptical than Earth’s. During Martian winter, it travels further from the Sun compared to a circular orbit. During that period, the deuterium emissions are very faint.

This is where the Hubble Space Telescope comes in. It contributed observations from its two high spectral resolution UV instruments, the Goddard High Resolution Spectrograph (GHRS) and the Space Telescope Imaging Spectrograph (STIS). By combining the Hubble observations and the MAVEN data, Clarke and his team monitored deuterium escape for three complete Martian years.

Hubble also contributed data that predates the MAVEN mission. Hubble’s data is critical because the Sun drives the atmospheric escape, and its effect changes throughout the Martian year. The closer Mars is to the Sun, the more rapidly water molecules rise through the atmosphere, where they split apart at high altitudes.

These Hubble images of Mars at aphelion (top) and perihelion (bottom) show how its atmosphere is brighter and more extended when Mars is closer to the Sun. Image Credit: NASA, ESA, STScI, John T. Clarke (Boston University); Processing: Joseph DePasquale (STScI)

The Sun’s effect on the Martian atmosphere is striking.

“In recent years scientists have found that Mars has an annual cycle that is much more dynamic than people expected 10 or 15 years ago,” explained Clarke. “The whole atmosphere is very turbulent, heating up and cooling down on short timescales, even down to hours. The atmosphere expands and contracts as the brightness of the Sun at Mars varies by 40 percent over the course of a Martian year.”

Prior to this research, Mars scientists thought that hydrogen and deuterium atoms slowly diffused upward through the thin atmosphere until they were high enough to escape. But these results change that perspective.

These results show that when Mars is close to the Sun, water molecules rise very rapidly and release their atoms at high altitudes.

“H atoms in the upper atmosphere are lost rapidly by thermal escape in all seasons, and the escape flux is limited by the amount diffusing upward from the lower atmosphere so that the escape flux effectively equals the upward flux,” the authors explain in their research.

It’s different for deuterium atoms, though. “The D escape flux from thermal escape is negligible, in which case an upward flux with the water-based D/H ratio would result in a large surplus of D in the upper atmosphere,” the authors write.

For the D/H ratio to be restored to the measured equilibrium with H near aphelion and to be consistent with observed faster changes in D density near perihelion, something has to boost the escape of D atoms. “In this scenario, the fractionation factor becomes much larger, consistent with a large primordial reservoir of water on Mars,” the authors write. “We consider this to be the likely scenario, while more work is needed to understand the physical processes responsible for superthermal atoms and their escape.”

“Overall, the results presented here offer strong supporting evidence for a warm and wet period with an abundance of water on early Mars and a large amount of water loss into space over the lifetime of the planet,” Clarke and his colleagues write.

The research also reached another conclusion. The upper Martian atmosphere is cold, so most of the atoms need a boost of energy to become superthermal and escape Mars’ gravity. This research shows that solar wind protons can enter the atmosphere and collide with atoms to provide the kick. Sunlight can also provide an energy boost through chemical reactions in the upper atmosphere.

This research doesn’t answer all of our questions about Mars’s lost water, but it makes significant progress, and that’s always welcome.

“The trends reported here represent substantial progress toward understanding the physical processes that govern the escape of hydrogen into space at Mars and our ability to relate these to the isotopic fractionation of D/H and the depth of primordial water on Mars,” the authors write.

How Mars lost its water is one of the big questions in space science right now. It’s about more than just Mars; it can help us understand Earth, Venus, and the rocky exoplanets we find in other habitable zones and how they evolve.

To put it bluntly, Mars lost its water, and Earth didn’t. Why?

We’re inching toward the answer.

The post One Step Closer to Solving the Mystery of Mars’ Lost Water appeared first on Universe Today.

Bands of fast-moving wind that blow west to east around the globe play a crucial role in weather – a poleward shift in parts of these jet streams could cause dramatic changes in weather from the western US to the Mediterranean

Charging new lithium-ion batteries with high currents can significantly increase their total lifespan

A new filtration material might provide a nature-based solution to water contamination by PFAS chemicals. The material, based on natural silk and cellulose, can remove a wide variety of these 'forever' chemicals as well as heavy metals, and its antimicrobial properties can help keep the filters from fouling.

A widely used disinfectant worldwide, chloroxylenol, has been associated with eco-toxicological threats in water environments due to its relatively high chemical stability and massive consumption. Researchers have discovered a promising alternative known as 2,6-dichlorobenzoquinone (2,6-DCQ), which works more effectively in combating certain common bacteria, fungi and viruses, and can be rapidly degraded and detoxified in receiving waters.

An AI-powered tool can distinguish dark matter's elusive effects from other cosmic phenomena, which could bring us closer to unlocking the secrets of dark matter.

An AI-powered tool can distinguish dark matter's elusive effects from other cosmic phenomena, which could bring us closer to unlocking the secrets of dark matter.

An AI-powered tool can distinguish dark matter's elusive effects from other cosmic phenomena, which could bring us closer to unlocking the secrets of dark matter.

A team models the atmospheres of distant planets using neural networks.

Physicists have created a one-dimensional gas out of light. This has enabled them to test theoretical predictions about the transition into this exotic state of matter for the first time. The method used in the experiment by the researchers could be used for examining quantum effects.

A new study has unveiled a new class of quantum critical metal, shedding light on the intricate interactions of electrons within quantum materials. The research explores the effects of Kondo coupling and chiral spin liquids within specific lattice structures.

A new study has unveiled a new class of quantum critical metal, shedding light on the intricate interactions of electrons within quantum materials. The research explores the effects of Kondo coupling and chiral spin liquids within specific lattice structures.

New findings from a global team of expert scientists in academia and industry has generated new research quality standards that will help slash costs and reduce the time it takes to develop advanced nanomedicine treatments and make them available for patients.