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One of the greatest cosmological mysteries facing astrophysicists today is Dark Matter. Since the 1960s, scientists have postulated that this invisible mass accounts for most of the matter in the Universe. While there are still many unresolved questions about it – i.e., What is it composed of? How do we detect it? What evidence is there beyond indirect detection? – we have managed to learn a few things about it over time.

For example, astrophysicists have observed that Dark Matter played a vital role in the formation of galaxies and is responsible for keeping them gravitationally bound. However, when an international team of astronomers observed the ultra-diffuse galaxy AGC 114905, they found no evidence of Dark Matter at all. If these observations are accurate, this discovery could force scientists to reevaluate their cosmological models and the way we look at the Universe.

The research team was led by researchers from the Kapteyn Astronomical Institute at the University of Groningen and the Netherlands Institute for Radio Astronomy (ASTRON). They were joined by astronomers and cosmologists from the University of Durham, Valparaiso University, and the University of Illinois. Their research findings were accepted for publication and will appear in the Monthly Notices of the Royal Astronomical Society.

As the team explained in a previous study, the road to this discovery began when Pavel Mancera Piña – a Ph.D. student with the University of Groningen and ASTRON and the lead author on both papers – and his colleagues observed six galaxies that appeared to have little or no dark matter. These findings contradicted prevailing theories about dark matter, which states that all galaxies (especially ultra-diffuse dwarf galaxies) could not exist without dark matter to hold them together.

Piña and his colleagues were instructed to retake their measurements and used the Very Large Array (VLA) in New Mexico to conduct an observation campaign of one galaxy in particular. This was AGC 114905, a gas-rich, ultra-diffuse dwarf galaxy located about 250 million light-years away in the constellation Pisces. This designation refers to the fact that it is a low luminosity galaxy with far fewer stars than galaxies like ours (despite being comparable in size).

During this campaign, the team collected data on the rotation of gas in AGC 114905 for 40 hours between July and October 2020. They then made a graph that showed the distance of the gas from the center of the galaxy (x-axis) and the rotational speed of the gas (y-axis), which is a standard way of revealing the influence of dark matter. This graph showed that the presence of normal matter alone could explain the motions of the gas in AGC 114905.

As Piña explained in a recent Royal Astronomical Society press release:

“This is, of course, what we thought and hoped for because it confirms our previous measurements. But now the problem remains that the theory predicts that there must be dark matter in AGC 114905, but our observations say there isn’t. In fact, the difference between theory and observation is only getting bigger.”

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Simulation of dark matter and gas. Credit: Illustris Collaboration (CC BY-SA 4.0)

As Piña and his colleagues indicate in their study, there are several possible explanations for the lack of dark matter. For starters, AGC 114905 may have been stripped of its dark matter through tidal interaction with neighboring large galaxies. They also adjusted the parameters of the Lamba-Cold Dark Matter (?CDM) cosmological model and alternate theories to General Relavity to obtain values consistent with their observations. But as Piña explained, none of it worked:

“But there are none. And in the most reputed galaxy formation framework, the so called cold dark matter model, we would have to introduce extreme parameter values that are far beyond the usual range. Also with modified Newtonian dynamics, an alternative theory to cold dark matter, we cannot reproduce the motions of the gas within the galaxy.”

Another possibility they considered was that their estimates of the estimated angle at which
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Powerful Jets From a Black Hole are Spawning Star Clusters

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Supermassive black holes are messy feeders, and when they’re gorging on too much material, they can hurl high-energy jets into the surrounding Universe. Astronomers have found one of the most powerful eruptions ever seen, emanating from a black hole 3.8 billion light-years away. The powerful jets are blowing out cavities in intergalactic space and triggering the formation of a huge chain of star clusters.

The black hole is part of a massive galaxy cluster, named SDSS J1531, which contains hundreds of individual galaxies, and all these galaxies have huge reservoirs of hot gas and dark matter. Using several telescopes for multiwavelength observations — including the Chandra X-ray Observatory, the Low Frequency Array (LOFAR) radio telescope, the Atacama Large Millimeter and submillimeter Array (ALMA), the Gemini North telescope’s Gemini Multi-Object Spectrograph (GMOS), and the Very Large Array (VLA) — astronomers were able to discern that two of the central galaxies were engaged in a major merger. The merger activated the supermassive black hole in the center of one of the large galaxies, which produced an extremely powerful jet. As the jet moved through space, it pushed the surrounding hot gas away from the black hole, creating a gigantic cavity.

The merger and the resulting jets from the black hole created a remarkable and stunning chain of 19 young stellar superclusters wound the two galaxies like a string of beads.

In their paper, the astronomers said the dynamic environment of SDSS J1531 offers an excellent laboratory to study the interplay between mergers, and their multiwavelength studies allowed them to uncover the origin and evolution of the “beads on a string” star formation complex.

“We’ve reconstructed a likely sequence of events in this cluster that occurred over a vast range of distances and times,” said co-author Grant Tremblay, from the Harvard & Smithsonian Center for Astrophysics CfA). “It began with the black hole a tiny fraction of a light-year across forming a cavity almost 500,000 light-years wide. This single event set in motion the formation of the young star clusters nearly 200 million years later, each a few thousand light-years across.”

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A labeled view of the multiwavelength Image of SDSS J1531. Credit: X-ray: NASA/CXC/SAO/O. Omoruyi et al.; Optical: NASA/ESA/STScI/G. Tremblay et al.; Radio: ASTRON/LOFAR; Image Processing: NASA/CXC/SAO/N. Wolk.

Chandra’s X-ray vision allowed the scientists to see wing-shaped emissions in bright X-rays, which traced dense gas near the center of SDSS J1531. The said these wings make up the edge of the cavity, and then LOFAR revealed radio waves from the remains of the jet’s energetic particles filling in the giant cavity. Together, these data provide compelling evidence of an ancient, massive explosion.

Osase Omoruyi, also from CfA who led the study, compared finding this cavity to unearthing a buried fossil.

“We are already looking at this system as it existed four billion years ago, not long after the Earth formed,” she said. “This ancient cavity, a fossil of the black hole’s effect on the host galaxy and its surroundings, tells us about a key event that happened nearly 200 million years earlier in the cluster’s history.”

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This Hubble Space Telescope image from 2014 shows two galaxies (yellow, center) from the cluster SDSS J1531 found to be merging into one and a “chain” of young stellar super-clusters are seen winding around the galaxies’ nuclei. The galaxies are surrounded by an egg-shaped blue ring caused by the immense gravity of the cluster bending light from other galaxies beyond it. Credit: NASA/ESA/Grant Tremblay

You can learn more about a
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Finally! Blue Origin’s New Glenn Goes Vertical on the Launch Pad

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If you think about space travel and the means of escaping the confines of the Earth then most people, currently, are likely to think about the new Artemis project and the Space Launch System. That’s not the only new development though, Blue Origin have been working on their New Glenn rocket and finally we have got a glimpse of their new offering. The rocket was finally rolled onto the launch pad at Cape Canaveral for testing to commence and we may even see a launch later this year.

Blue Origin was founded in 2000 by the founder of Amazon, Jeff Bezos. It is American aerospace manufacturer based in Washington, USA and specialises in producing rocket engines for the Vulcan rocket and manufactures satellites, spacecraft and a variety of space based tech. Securing the deal to become the second provider of the Lunar lander for Artemis project, Blue Origin has most certainly become a major player in the space industry.

Their latest announcement came with the incredible sight of the New Glenn vehicle rolling out onto Launch Complex 36 at Cape Canaveral. This was the first glimpse the world got of their new advanced heavy-lift vehicle which promises to support a number of different commercial customer missions and NASA’s Artemis program to get humans back to the Moon.

Space lovers will perhaps recognise the name Glenn from the first American to orbit the Earth, John Glenn. It stands an impressive 98m tall (only about 12m shorter than Saturn V used by the Apollo astronauts). It has an impressive 7m payload bay which is double the volume of most commercial launch capabilities available today. I don’t know about you but I struggle to visualise what that means but to give it context, Blue Origin state that it could accommodate three school busses! 

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Apollo 11 launch using the Saturn V rocket

The first stage, like the Falcon rockets, are reusable and designed to be used for at least 25 launches. They will land on a sea-based platform almost 1,000km downrange from the launch site. As with the Falcon systems, the reusability of the first stage helps to keep costs per launch down.

Before the New Glenn could be lifted up onto the pad the journey started toward the end of 2023 when the first stage module was transported to the Integration Facility 15km away. The facility allowed the modules to be assembled in preparation for installing on the launch pad. Now the rocket is vertical, the coming weeks will see a series of tests from loading the cryogenic fuel into the seven BE-4 engines. These are the most powerful liquid oxygen and liquefied natural gas engines developed since Saturn V’s F1 engines. They will test pressure control and launch and ground systems in preparation for its first launch later this year.

Blue Origin are rather confident these tests will be a success though as they are already manufacturing several New Glenn vehicles with a full set of customers queueing up to use them. They include NASA, Project Kuiper (another global internet project to launch over 3,000 satellites into low Earth orbit), Telesat, Eutelsat and the US Space Force for National Security Space Launch programs.

Source : Blue Origin Debuts New Glenn on Our Launch Pad

The post Finally! Blue Origin’s New Glenn Goes Vertical on the Launch Pad appeared first on Universe Today.

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Can We Survive in Space? It Might Depend on How Our Gut Microbiome Adapts

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For over a century, people have dreamed of the day when humanity (as a species) would venture into space. In recent decades, that dream has moved much closer to realization, thanks to the rise of the commercial space industry (NewSpace), renewed interest in space exploration, and long-term plans to establish habitats in Low Earth Orbit (LEO), on the lunar surface, and Mars. Based on the progression, it is clear that going to space exploration will not be reserved for astronauts and government space agencies for much longer.

But before the “Great Migration” can begin, there are a lot of questions that need to be addressed. Namely, how will prolonged exposure to microgravity and space radiation affect human health? These include the well-studied aspects of muscle and bone density loss and how time in space can impact our organ function and cardiovascular and psychological health. In a recent study, an international team of scientists considered an often-overlooked aspect of human health: our microbiome. In short, how will time in space affect our gut bacteria, which is crucial to our well-being?

The team consisted of biomedical researchers from the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC) at the Shiraz University of Medical Sciences (SUMS), the Lebanese International University, the International University of Beirut, the MVLS College at The University of Glasgow, the Center for Applied Mathematics and Bioinformatics (CAMB) at Gulf University in Kuwait, the Nuclear Physics Institute (NPI) of the Czech Academy of Sciences (CAS), and the Technische Universität Wien Atominstitut in Vienna. The paper that describes their findings recently appeared in Frontiers of Microbiology.

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Artist’s impression of the Space Launch System (SLS) taking off. Credit: NASA

A microbiome is the collection of all microbes that live on and within our bodies, including bacteria, fungi, viruses, and their respective genes. These microbes are key to how our body interacts with the surrounding environment since they can affect how we respond to the presence of foreign bodies and substances. In particular, some microbes alter foreign bodies in ways that make them more harmful, while others act as a buffer that mitigates the effects of toxins. As they note in their study, the microbiota of astronauts will encounter elevated stress from microgravity and space radiation, including Galactic Cosmic Rays (GCR).

Cosmic rays are a high-energy form of radiation that consists primarily of protons and atomic nuclei stripped of their electrons that have been accelerated to close to the speed of light. When these rays are generated from elements heavier than hydrogen or helium, their high-energy nuclei components are known as HZE ions, which are particularly hazardous. When these impact our atmosphere or protective shielding aboard spacecraft or the International Space Station (ISS), they result in showers of secondary particles.

While Earth’s protective magnetosphere and atmosphere prevent most of these particles from reaching the surface, astronauts in space are exposed to them regularly. As the authors noted, previous research has shown how this exposure could potentially enhance astronaut resilience to radiation, a process known as radio-adaptation. However, they also noted that the extent to which astronauts adapted varied from one astronaut to the next, with some experiencing adverse biological effects before embarking on a deep space mission.

For this reason, they recommend conducting further research to determine the risks associated with the space environment, as it mostly consists of protons, which astronauts will be exposed to before encountering HZE particles. Third, NASA’s Multi-Mission Model suggests that an astronaut’s first mission can be an adapting dose. However, the team notes that current research suggests that a second spaceflight does not necessarily increase the chances of genetic abnormalities as much as expected. This could mean that the
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