After a few significant solar flares over the past few days, the chances of auroras (i.e. northern and southern lights) is high enough that it’s probably worth keeping an eye on polar skies for the next couple of nights. At the moment the forecast is for the best chances to be in Asia, but forecasting auroras is far from an exact science, and there could be surprises.
The Aurora Borealis, or Northern Lights, shines above Bear Lake, Alaska. USAF photo: credit Senior Airman Joshua StrangTo know when to start looking, I keep an eye on data from the ACE satellite. When a cloud of slow particles from a solar flare’s coronal mass ejection arrives, ACE’s data goes all haywire; you’ll see it as a sudden change in the plots’ appearance, as shown below. ACE satellite sits 950 thousand miles [1.5 million kilometers] from Earth, and is located between Earth and the Sun. At that vantage point, it gives us (and our other satellites) a little early warning, of up to an hour.
Another good place to look is NOAA’s space weather dashboard. Its first panel, an example of which is shown below, displays three plots; the bottom plot is called “Geomagnetic Activity”. When that plot goes deep orange or red, then there’s probably some serious auroras going on in areas where they aren’t so often seen.
But be warned — the plot shows not what is happening now but what happened in a three-hour interval that is already past. If a geomagnetic storm is long enough, that’s still useful, but be aware that the data is out of date by the time we get to see it. That’s why the ACE satellite may well give you the best heads-up.
One of the hazards astronauts must contend with is muscle loss. The more time they spend in a microgravity environment, the more muscle loss they suffer. Astronauts use exercise to counter the effects of muscle atrophy, but it’s not a perfect solution. Researchers want to develop drugs to help, and understanding the muscle-loss process in space is a critical first step.
In the early days of space travel, researchers weren’t certain what effects microgravity had on astronauts. As the length of space missions grew and scientific monitoring became more prevalent, researchers gained a better understanding of the problem. After the Skylab missions in 1973 and 1974, researchers acquired better data and began to reach some conclusions. It was clear that microgravity contributed to a host of health problems, and muscle atrophy was among them.
Many of the problems astronauts suffer mimic the same problems stemming from aging.
“Space is a really unique environment that accelerates qualities associated with aging and also impairs many healthy processes,” said Ngan Huang, an associate professor at Stanford University. “Astronauts come back with muscle atrophy, or a reduction of muscle function, because the muscle isn’t being actively used in the absence of gravity. As space travel becomes more common and available to civilians, it’s important to understand what happens to our muscle in microgravity.”
Huang is the co-author of new research published in the journal Stem Cell Reports. The study is “Skeletal muscle-on-a-chip in microgravity as a platform for regeneration modeling and drug screening.”
Age-related muscle loss is called sarcopenia. Many factors, including immobility, hormonal changes, and even nutrition, contribute to sarcopenia. Currently, there aren’t any FDA-approved drugs to treat the condition, so exercise, lifestyle, and nutrition are the only ways to treat it. Exercise is critical for astronauts in their struggle against muscle loss. However, space for exercise equipment is limited on the ISS. An effective medication to treat astronaut sarcopenia would be a huge boon.
In this new research, the researchers grew live muscle cells on scaffolds on tiny chips and then sent them for study in microgravity aboard the ISS. The cells grew for seven days under the watchful eyes of astronauts and were exposed to a pair of used to counteract sarcopenia and enhance muscle regeneration. Then, they compared the microgravity muscle cells to ones grown under normal gravity in a lab here on Earth.
This figure from the research gives an outline of the study. (A) shows human muscle cells were seeded onto collagen scaffolds, then placed into a bioreactor with media to become muscles on a chip. (B) shows an overview of the experiment, including travelling to the ISS, being exposed to different drugs, and later extracted and analyzed. Image Credit: Kim et al. 2024.The results showed that the microgravity muscle cells had impaired muscle fibre formation, differences in gene activity, and differences in their protein profiles.
Muscle tubes, or myotubes, are precursors to muscle fibres. The study results showed reduced myotube length and width, as well as a reduced fusion index. The fusion index basically tells researchers how many muscle cell nuclei are present.
The mitochondria generate most of a cell’s energy, and the results showed that genes affecting their function were compromised. Since muscles have such high metabolic function, any impairment to mitochondria will play out in reduced muscle regeneration. Results also showed that genes associated with forming fat were bolstered. The researchers say the combined effect takes a large toll on muscle regeneration in microgravity.
Protein profiles are like snapshots of what cellular machinery is doing at a particular time. They reveal critical information about the cell’s function and health. In this research, the team examined 200 different proteins.
The results showed that five proteins were produced in greater abundance. Two of those are associated with chronic inflammation, and one is “a biomarker for mitochondrial dysfunction and cellular senescence.” Four of the proteins showed reduced abundance. One of those is “an important player in the maintenance of muscle and myogenesis,” the researchers write in their paper.
This image shows the “muscles-on-a-chip” experiment. Image Credit: Kim et al. 2024.Overall, the changes the muscle cells underwent shared similarities with changes induced by aging.
“We think our research on muscle chips in microgravity may have broader implications on sarcopenia,” says Huang. “Sarcopenia usually takes decades to develop on Earth, and we think that microgravity may have some ability to accelerate the disease process in orders of days.”
The research also helped understand the role drugs could play. “We next used the muscle-on-a-chip platform to perform proof-of-concept drug screening studies,” the researchers write. They exposed the cells to drugs used to counteract sarcopenia and enhance muscle regeneration.
Geneticists use the terms down-regulation and up-regulation to describe negative and positive effects on gene expression. They found that 286 genes were down-regulated in microgravity. Of those, 200 showed a positive response to drug treatment and similar expression levels to cells in normal gravity.
These Venn diagrams from the research show upregulated genes (left) and downregulated genes (right) in microgravity. The two drugs tested in the research are IGF-1 and 15-PDGH-i. The study showed that 286 genes in muscle tissue are downregulated in microgravity and that 200 of them responded positively to drugs. Image Credit: Kim et al. 2024.“In conclusion, we show that engineered muscle-on-a-chip bioconstructs exposed to microgravity induced prominent changes to their transcriptome that mimic aspects of impaired myogenesis,” the authors write.
Space research is difficult and resource-intensive, so the researchers intend to continue their work using equipment that mimics microgravity to dig deeper into the issue here on Earth. In 2025, the muscles-on-a-chip are scheduled for another space flight. That experiment will help to identify more drugs that can combat muscle loss.
The benefits of this research extend beyond just muscle loss. “This concept of engineered tissue chip platform in microgravity is a potentially transformative tool that could allow us to study a variety of diseases and do drug screening without animal or human subjects,” says Huang.
The authors conclude in their paper, “This work further highlights the utility of microgravity as a unique environment for drug discovery.”
The post Being in Space Mimics Age-Related Muscle Loss appeared first on Universe Today.
What does it take to have life at another world? Astrobiologists say you need water, warmth, and something for life to eat. If it’s there, it’ll leave signs of itself in the form of organic molecules called amino acids. Now, NASA scientists think that those “signatures” of life—or potential life—could exist just under the icy surfaces of Europa and Enceladus.
If future explorations find those signatures, it’ll make a major step in the search for life elsewhere in the Solar System—and beyond. That’s one reason why robotic missions will someday land on those moons—to look for the signs of life. The next mission to Europa, called Europa Clipper, will orbit that tiny moon, but won’t land. However, it will look for environments suitable for life. So, that’s a start. There’s also a proposed mission called Enceladus Orbilander. It could launch in 2038 and spend a year checking out that moon.
The Search for Life SignsScientists strongly suspect there’s a warmish salty ocean beneath the ices of both Europa and Enceladus. Moreover, they are probably heated by tidal stresses. So, those are two of the ingredients for life right there. Given what we know about these worlds, there could be something to feed that life, too.
If life does exist, it could “imprint” its existence in the form of amino acids, nucleic acids, and other organic molecules in the surface ice. Life probably wouldn’t exist right on the surface, mostly due to radiation and the lack of atmosphere at those worlds. That makes the near sub-surface ice a good place to look for evidence of that life. That will require a little digging to find the evidence. How deep? According to Alexander Pavlov of NASA Goddard Space Flight Center, it wouldn’t be far.
“Based on our experiments, the ‘safe’ sampling depth for amino acids on Europa is almost 8 inches (around 20 centimeters) at high latitudes of the trailing hemisphere (hemisphere opposite to the direction of Europa’s motion around Jupiter) in the area where the surface hasn’t been disturbed much by meteorite impacts,” Pavlov said. “Subsurface sampling is not required for the detection of amino acids on Enceladus – these molecules will survive radiolysis (breakdown by radiation) at any location on the Enceladus surface less than a tenth of an inch (under a few millimeters) from the surface.”
Testing that HypothesisOf course, scientists don’t have any samples of ice on hand to study from either Europa or Enceladus. So, Pavlov’s team simulated the conditions to see if rovers and landers could find evidence of organic materials and life on those worlds. They used amino acids in ice and those from dead microorganisms in radiolysis experiments as possible representatives of biomolecules on icy moons. Radiolysis uses ionizing radiation to bombard molecules and break them apart.
Experimental samples of amino acids (as fingerprints of life) were loaded into a dewar and bombarded by gamma radiation. Credit: Candace Davison.The team mixed samples of amino acids with ice chilled to about -196 Celsius and bombarded them with gamma rays. Since the oceans might host microscopic life, they also tested the survival of amino acids in dead bacteria in ice. Finally, they tested samples of amino acids in ice mixed with silicate dust. That tested the potential mixing of material from meteorites or the interior with surface ice.
Amino acids are interesting because life can create them. Other non-biological chemistry processes also make them. Scientists studied specific kinds of amino acids that could exist on Europa or Enceladus, particularly those amino acids from the microorganisms they tested (called A. woodii). If other microorganisms similar to that one existed at Europa or Enceladus, they could be a potential sign of life. That’s because they are used by terrestrial life as a component to build proteins. Those make enzymes that speed up or regulate chemical reactions and make structures.
Moving Evidence of Life to the Icy SurfaceIf such life did exist on either world’s subsurface oceans, the next question is how its “fingerprint” amino acids get to the ice so close to the top layers of ice. There’s evidence of resurfacing at both worlds by ocean water from below. On Europa, there are surface units much younger than others, which indicates that water makes its way to the surface and freezes. On Enceladus, geysers shoot material out to space from below the surface. Amino acids and other compounds from subsurface oceans could be brought to the surface by geyser activity or the slow churning motion of the ice crust.
Europa’s bizarre surface features suggest an actively churning ice shell above a salty liquid water ocean. That liquid could carry amino acids and signs of life to the surface. Credit: JPLSo, it looks like the team’s experiment shows that amino acids could survive on both worlds, under certain conditions, but they also degrade at different rates. That’s important news for future missions, according to Pavlov.
“Slow rates of amino acid destruction in biological samples under Europa and Enceladus-like surface conditions bolster the case for future life-detection measurements by Europa and Enceladus lander missions,” he said. “Our results indicate that the rates of potential organic biomolecules’ degradation in silica-rich regions on both Europa and Enceladus are higher than in pure ice and, thus, possible future missions to Europa and Enceladus should be cautious in sampling silica-rich locations on both icy moons.”
For More InformationNASA: Life signs Could Survive Near Surfaces of Enceladus and Europa
The post We Might Find Life Just Under the Surface on Europa appeared first on Universe Today.
Like several people I know, I’m caught up in a temporary fit of the downs because the world seems to be going off kilter. I worry about politics, I worry about Israel, I worry about Ukraine, I worry about Iran and its forthcoming nukes, I worry about fulminating wokeness and its effect on science, and, well, the list goes on. But something is keeping me awake at night. Although I don’t lie abed racked with conscious worries, my theory (which is mine) is that the worry has become internalized. Further, it’s hard, for me at least, to avoid converting the worry into anger, as it’s made me short-tempered, so I have to exert more control over my behavior.
So much for the personal stuff. But since all the stuff I have to write about is depressing (in the wings are articles about the ideological capture of chemistry, Wikipedia’s “Jewish problem”, the school curriculum in New Zealand—in other words, the kind of thing you see her regularly), there’s no light at the end of the tunnel. I’m thinking of writing about more personal stuff, just to improve my writing and go off on a different tangent. But there will always be the Hili dialogues with their daily five news items.
Do recall that on Saturday I leave for a month in South Africa, and posting will be very sparse for that month and somewhat sparse from now until Saturday.
So let’s have a couple of polls—about politics, of course. Please vote if you’re reading this and, more important, explain your feelings below if you wish.
First poll:
Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.Second poll (remember, all answers are anonymous and I don’t know who votes which way):
Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.Weigh in below. You needn’t tell me that this is not a scientific poll. It’s simply a survey of the readers.