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Seismology has been ubiquitous on Earth for decades, and missions such as InSight have recently provided the same data for the inside of Mars. Understanding a planet’s inner workings is key to understanding its geology and climate. However, the inner workings of Venus, arguably our closest sister planet, have remained a mystery. The sulfuric acid cloud and scorching surface temperatures probably don’t help. But Siddharth Krishnamoorthy from NASA’s Jet Propulsion Laboratory and Daniel Bowman of Sandia National Laboratory think they have a solution – use seismometers hanging from balloons.

As we reported previously, the idea has been around for a while. However, it might seem counter-intuitive – don’t seismometers usually have to sit on the ground to detect something? Typical seismometers do, yes. However, another type of seismometer is only now becoming more accepted. An infrasound seismometer monitors infrasound pressure waves created by seismic activity transmitted through a medium other than the ground – like an atmosphere.

Venus has plenty of atmosphere to go around, so it sounds like an ideal place to use the technology. Even better, high up in its cloud layer is one of the places in the solar system most like the environment on Earth hence why there have been plenty of ideas to form “cloud cities” on Venus. 

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Artist’s depiction of a balloon with sensor in Venus’ atmosphere.
Credit – NASA / JPL-Caltech

It’s unnecessary to build an entire city simply to host some sensors collecting infrasound data, so a high-altitude balloon would serve the purpose nicely. That solves one of the most difficult challenges of exploring Venus – developing materials that can survive on its surface. NASA has spent millions of dollars developing radiation-hardened sensors that can withstand the extraordinary pressure and temperatures on the surface. But even they are relatively simplistic, so a sensor held aloft at a reasonable temperature and pressure wouldn’t require any additional development efforts for that specific use case.

This begs the obvious question – how will the signal get from the ground to the sensors floating in the atmosphere? Earthquakes (or venusquakes, as in this case) cause deafening sounds, which are then transmitted through the atmosphere at low frequencies. Sensitive microphones, like the ones aloft in the balloon, could read these signals.

Such an experiment was recently carried out on Earth, where an infrasound microphone could pick up signals from two earthquakes of magnitude 7.3 and 7.5, despite being 3,000 km away from the epicenter of the earthquakes up in the stratosphere. Using this experiment as a template, researchers could develop a similar system for use on Venus, with the associated changes necessary for that particular planet’s environment. Also, it was much farther away than previous experiments done with infrasound seimometers, and much closer to the actual distance any such sensor would be in from the epicenter of a venusquake.

Venus is an increasingly interesting option for exploration – Fraser explains why.

There are still plenty of challenges, though. One is that we haven’t been able to successfully launch a balloon mission to Venus at all, let alone one with sensitive seismometers on it. Second is that, in the case of the Earth experiment, we had a “ground truth,” i.e., the researchers knew from other sources there was an earthquake happening when they received the signal. Since there are no other sensors capable of providing that validation on Venus, researchers would likely have to speculate on what caused a particular pattern in the data – it could be a venusquake, or maybe the balloon was jostled in a certain way.

In addition, earthquakes with magnitudes above seven are considered large here on Earth, and it’s unclear if the seismometers could pick up smaller quakes, even here on our home planet. Venus might have the same range of resultant seismic activity, or it could be even more active but with less intensity, making the detection of less powerful quakes a priority. The JPL team has picked up aftershocks as low as magnitude 4.2, however the balloon as that point was much closer than a few thousand kilometers away.

Utilizing technologies developed on Earth in space exploration is always a good idea, and this seems to be a novel way of using these seismometers in a novel way. However, as of now, there are no plans for a mission utilizing these features, despite almost a dozen planned missions to Venus in the near future. For
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An Astronaut Might Need Kidney Dialysis on the Way Home from Mars

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Long term space exploration comes with many challenges. Not least is how much toilet paper to take but more worryingly is the impact on human physiology. We have not evolved in a weightless environment, we are not used to floating around for months on end nor are we able to cope with increased levels of radiation. It is likely that organs like the kidneys will become damaged but it make take time for signs to appear. Researchers are developing ways to detect organ issues in the early stages and develop ways to protect them during long duration flights. 

We have known for some years that space flight causes health problems. Reduced muscle and bone density are the more well known but since the 1970’s we have also seen a weakening of the heart, eyesight issues and kidney stone development. The main cause of the problem is thought to be increased exposure to radiation from space. It’s not just the radiation from the Sun but Galactic Cosmic Radiation from deep space also plays a part. Fortunately for us here on Earth, the magnetic field protects us and those in low Earth orbit to a degree too. Those who travel further afield; to the Moon and other planets will be far more at risk. 

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ESA astronaut Alexander Gerst gets a workout on the Advanced Resistive Exercise Device (ARED). Credit: NASA

To date, no-one has attempted to study what might be happening inside our organs as a result of long duration space flight, until now. A new study, published in Nature Communications, reports upon the analysis of kidney health in space flight. The study was funded by Wellcome, St Peters Trust and Kidney Research UK and was undertaken by a team of researchers from over 40 groups.

The research team collected samples from over 40 low Earth orbit missions from humans and mice chiefly from the International Space Station. Using these samples they conducted biomolecular, physiological and anatomical assessments. Using mice, they were able to simulate Galactic Cosmic Radiation doses equivalent to a 1.5 year to 2.5 year Mars mission. 

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NASA Image: ISS020E049908 – NASA astronaut Nicole Stott, Expedition 20/21 flight engineer, is pictured near the Mice Drawer System (MDS) in the Kibo laboratory of the International Space Station.

Indications from the study showed that the kidney from both animal and human experienced changes. Parts of the kidney, known as tubules, are responsible for tweaking the calcium and salt balances and these showed signs of shrinkage after less than a month in space. The researchers believe though that this is more likely the result of weightlessness rather than radiation doses. The team did suggest however that further research is appropriate to see if the combination of increased doses of radiation coupled with microgravity had an increasing effect.

Another finding of the study was the way in which salt is processed by the kidneys. It is now thought that fundamental changes to how this is handled leads to the formation of kidney stones whilst it was originally assumed to be the result solely of microgravity.

Perhaps the most shocking finding of the study though was that anyone venturing beyond the confines fo the Earth’s protective magnetic field for 2.5 years is likely to experience permanent kidney damage and loss of function. This was demonstrated in the mice samples that had experienced a simulated Galactic Cosmic Radiation dose

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Moon Lander Detects Technosignatures Coming from Earth

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The search for life has to be one of the most talked about questions in science. The question is, what do you look for? The Odysseus lunar lander has recently detected signs of a technologically advanced civilisation…on Earth! The lander is equipped with an instrument called ROLSES which has probed the radio emissions from Earth as if it was an exoplanet to se if it could detect signs of life! 

Odysseus was launched on 15 February, it was the Intuitive Machines lunar lander and it touched down in the solar polar region of the Moon seven days later. Since then it has been collecting valuable data from the area as a prelude for future human exploration. It was part of the Commercial Lunar Payload Services program which have all been built by private companies. Despite the hiccup of a landing where Odysseus tipped onto its side it has still been performing well.

There have been other challenges along the way. The laser guided navigation system which was supposed to aid the landing over the rocky surface failed. In a nod to Armstrong landing Apollo 11 manually in the last few minutes, the ground crew had to land using the optical camera system alone.  Even the journey to the Moon was not without incident. One of the antennae of the ROLSES system overheated and became dislodged from its housing.  On landing, an image showed the antenna sticking out. 

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Neil Armstrong and Buzz Aldrin plant the US flag on the Lunar Surface during 1st human moonwalk in history 45 years ago on July 20, 1969 during Apollo 1l mission. Credit: NASA

On board Odysseus is the Radio wave Observations at the Lunar Surface of the photo Electron Sheath or ROLSES for short. It is a radio experiment designed to explore properties of the Earth’s atmosphere from the surface of the Moon. It was a unique opportunity to observe Earth in a completely different way and, to see if our approach for hunting for technologically capable alien civilisations are correct.

The instrument was built at NASA’s Goddard Space Flight Center in Maryland and included radio antennae and a device called a radio spectrometer. It’s purpose was to record a wide range of radio emissions from the ‘radio quiet’ locale of the Moon. It turned out to be a bit of a bonus though as the team were able to record radio waves coming from Earth for about an hour and a half. 

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NASA has selected three commercial Moon landing service providers that will deliver science and technology payloads under Commercial Lunar Payload Services (CLPS) as part of the Artemis program. Each commercial lander will carry NASA-provided payloads that will conduct science investigations and demonstrate advanced technologies on the lunar surface, paving the way for NASA astronauts to land on the lunar surface by 2024…The selections are:..• Astrobotic of Pittsburgh has been awarded $79.5 million and has proposed to fly as many as 14 payloads to Lacus Mortis, a large crater on the near side of the Moon, by July 2021…• Intuitive Machines of Houston has been awarded $77 million. The company has proposed to fly as many as five payloads to Oceanus Procellarum, a scientifically intriguing dark spot on the Moon, by July 2021…• Orbit Beyond of Edison,
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The Inner and Outer Milky Way Aren’t the Same Thickness, and that’s Surprising

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At first glance, the universe and night sky seem largely unchanging. The reality is very different, even now, a gas cloud is charging toward the Milky Way Galaxy and is expected to crash into us in 27 million years. A team of astronomers hoping to locate the exact position of the expected impact site have been unsuccessful but have accidentally measured the thickness of the Milky Way! Analysing radio data, they have been able to deduce the thickness of the inner and outer regions and discovered a dramatic difference between the two. 

The team of astronomers from the US National Science Foundation’s Green Bank Observatory were attempting to study the Smith Cloud. This high velocity cloud of hydrogen gas is located in the constellation Aquila at a distance of somewhere between 36,000 and 45,000 light years. Previous studies from the Green Bank Observatory have shown the cloud contains at least 1 million times the mass of the Sun and measures 9,800 light years long by 3,300 light years wide. 

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A false-color image of the Smith Cloud made with data from the Green Bank Telescope (GBT). New analysis indicates that it is wrapped in a dark matter halo. Credit: NRAO/AUI/NSF

The plan was simple enough, to observe the spot where the cloud is currently interacting with the Milky Way. The observation is tricky enough though as the cloud is on the far side of the Milky Way and there is a lot of stuff in the way! The team, led by Toney Minter used the 20m Green Bank Telescope to search for dust and emissions from hydroxyl molecules (composed of a hydrogen and oxygen molecule.)  What the team expected to see was a difference in composition in the region of the Milky Way interacted with the cloud which, should have very little dust and hydroxyl molecules. Clouds in the Milky Way tend to have both so a difference should be detectable. 

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The Robert C. Byrd Green Bank Telescope. Credit: Jay Young.

Minter was candidly open about the study joking ‘I knew there was a low probability that I’d find what I was looking for—and I didn’t,. But this is all part of the scientific process. You learn from what you DO and DON’T find.’

Disappointingly the team did not detect any differences in composition but what they did find was equally as interesting. The study revealed information about the Milky Way itself and the structure of its inner regions. Minter and his team had to look through the Milky Way’s inner regions for their study and what they were able to determine was the thickness of the layer of molecules in the inner Galaxy. The information enabled them to deduce the scale height of the clouds of molecular gas in the inner Milky Way. The results showed that the layer of molecules in the inner region measured 330 light years thick while those in the outer parts measured twice as much, around 660 light years.

The discovery still leaves questions unanswered. The observation certainly shows the difference in thickness between the inner and outer regions but it doesn’t give any clue as to what is driving the difference. Further observations are now required to follow up on this discovery to try and model the underlying process. Of course one other question remains unanswered and that is the nature and mechanics of the Smith Cloud and how it will impact our own Galaxy. Far from being disappointed though, Minter stated ‘That’s why astronomy is exciting, our knowledge is always evolving’

Source : While Aiming for
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