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Thirty-four years is a long time for a telescope. Yet, that is how long the veteran workhorse of NASA’s space telescope fleet has been operating. Admittedly, Hubble was served by several repair missions during the space shuttle era. Still, the system has been floating in the void and taking some of humanity’s most breathtaking pictures ever captured since April 24th, 1990. But now, time seems to be finally catching up with it, as NASA plans to limit some of its operations to ensure its continued life, starting with gyroscopes. 

Hubble has six gyroscopes, which are intended to help it orient in the right direction and ensure it stays oriented in that direction while it takes the extremely long-exposure, detailed images it is famous for. The six gyroscopes currently installed replaced six older ones during the final shuttle servicing mission in 2009. As one of the few moving components on Hubble, lasting 15 years without maintenance is pretty impressive.

That being said, not all of them lasted that long – only three are operational at this point, with the other three having failed at some point over the last 15 years. And on May 24th, the telescope was sent into safe mode by another failed gyro. This isn’t the first time that particular problem has happened either. Previous errors caused by the same gyro have caused Hubble to go into safe mode multiple times over the past few months. While engineers can reset it, the same problem repeatedly happening means it will probably continue.

Scott Manley explains how the gyros work on Hubble, and how the engineers plan to keep them working.
Credit – Scott Manley YouTube Channel

The problem is that the gyro is “saturating,” meaning that the sensor that shows its speed is maxing out even when the gyro itself isn’t moving near that speed. Since the spacecraft slewing at maximum speed could cause potential issues, the safe thing to do when reading a maximum speed on a gyro is to go into “safe mode” and ensure the spacecraft doesn’t wildly swing in one direction.

Operating in that mode makes sense, especially if the sensor readings are correct, but they make it almost impossible to move accurately if sensor readings aren’t correct. Given the previous efforts by Hubble’s engineering team to fix the problem, it appears at least one of the three remaining gyros is effectively inoperable from now on. So, the team now has a choice.

They could continue to operate with two gyros, or they could only use one and alternate which one they are using to not cause undue wear and tear on whichever one is selected for service first. According to a press release from the agency, operating with two gyros is effectively the same as operating with one, whereas operating with three had significant advantages in terms of speed and accuracy. So, the engineering team has decided that Hubble will operate in one gyro mode from now on.

Fraser discusses some of Hubble’s most iconic images – it’s set of Deep Fields.

This isn’t the first time it’s done so—Hubble effectively operated in one-gryo mode for a short time back in 2008 when the previous set of gyros was failing. It also operated in two-gyro mode from 2005 to 2009, when all the original gyros were replaced. So it is certainly possible, but what impact will it have?

It will take longer to lock on to targets, which is hardly surprising given the telescope’s age, but detrimental if it was hoping to catch transient events such as a supernova. It also won’t be able to track any moving objects that are closer than Mars, such as the occasional comet or asteroid. Typically, those types of objects weren’t the focal point of Hubble’s observations anyway. While Hubble will indeed have to slow down, its support team believes it can continue operations through at least the rest of this decade in this new mode.

Luckily, it is no longer alone in its role as the workhorse space telescope. The James Webb Space Telescope has far surpassed its observational capabilities; the Nancy Grace Roman Telescope, due to launch in 2027, will contribute additional functionality to make up for Hubble’s slowing pace. Hubble itself will always have a place in astronomy nerds’ hearts. Its Deep Field image is my favorite picture and sparked my love for astronomy as a kid. And I’m not alone – NASA recently rejected billionaire Jared Isaacman’s plan to service the aging telescope as part of a series of Dragon capsule missions. But even without additional help from the ground, Hubble hopefully still has a long, fruitful life ahead of it when it continues its science operations in mid-June.

Learn More:
NASA – NASA to Change How It Points Hubble Space Telescope
UT – Hubble Pauses its Science Again
UT – The Venerable Hubble Space Telescope Keeps Delivering
UT – Hubble Sees a Brand New Triple Star System

Lead Image:
This image of NASA’s Hubble Space Telescope was taken on May 19, 2009, after deployment during Servicing Mission 4.
Credit – NASA

The post It’s Time for Hardworking Hubble to Slow Down a Little appeared first on Universe Today.

People who had higher levels of xylitol in their blood were more likely to have a heart attack or stroke within the next three years, with lab experiments suggesting the sweetener promotes blood clotting

Industry is responsible for 23% of carbon emissions, close to the amount of electricity production (25%) and transportation (28%). We talk a lot about transportation and energy, but industrial carbon is a harder nut to crack. Also, the 23% is direct carbon release from industrial processes, if you include the energy used by industry the contribution is 30%. Industry and manufacturing is increasing at a steady rate worldwide, and by some estimates we could be seeing a 90% increase in CO2 release from industry by 2050. This could wipe out any gains we make in the energy and transportation sectors.

The two largest contributors to direct industrial carbon release are steel and cement. Cement production is responsible for about 8% of CO2 emissions, about a third of industrial release. Another third is from steel. So these two industries are a ripe target for reducing carbon emissions. To put the carbon footprint into perspective, if cement production were a country, it would be the third largest emitter after the USA and China.

The world produces 4.4 billion tons of concrete each year (cement is a main ingredient in concrete). This is excepted to increase to 5.5 billion tons by 2050. Some type of cement has been used by people for about 12,000 years, with the first concrete dating to about 800 BC. The Romans perfected concrete, and built an empire out of it. Today cement and concrete are essential building materials for our modern world.

About half of the CO2 from cement production comes from the following chemical reaction – CaCO3 + heat → CaO + CO2. CaCO3 is limestone, and the CaO is what is known as clinker, a main ingredient in cement. The other half of CO2 emissions comes from the energy necessary to heat the limestone to drive the reaction. Some of that CO2 is then absorbed back by concrete, but that takes decades. There are lots of proposals for how to reduce the carbon footprint of cement and concrete, or even eliminate it. The main barrier is that any such process needs to be done on a massive scale – able to make 4.4 billion tons per year and growing.

One proposal is to recycle old concrete. In this process the old concrete is crushed into a powder. That powder is then used as flux in the recycling of steel. When the ash is then collected from that steel production, it can be quickly cooled and hardened into clinker, which can be used to make fresh cement. At least this allows for a completely circular process for the recycling of old concrete. It also uses an existing industrial process of recycling steel. In order for this process to be truly green, however, the steel mills would have to use electric furnaces powered by green energy. There was about 360 million tons of concrete debris created in 2015, so that can take a chunk out of new concrete production – but this is obviously not a solution by itself (about 9% of concrete production).

Some proposals involve reducing the energy demands of cement production, mostly by using electricity in replace of heat. This can produce so-called room temperature cement. And again – if the power for the electricity comes from low CO2 sources, this can be a huge advantage. This same approach, by the way, has also been proposed for steel making – using electricity instead of heat generated by fossil fuel.

There are also many alternative cement recipes proposed. From what I can see these come in two basic flavors. The first adds ingredients to concrete to make the resulting concrete stronger and lighter. Perhaps the best option here, in terms of resulting physical properties, is carbon nanofibers, or graphene. This makes for strong and durable concrete, which means we can use less of it. In one study, “The resulting concrete was 25% lighter than concrete made with a normal aggregate, and showed a 32% increase in toughness, 33% in peak strain, and 21% in compressive strength.” So if we can use 30% or so less concrete, depending on the application, that right there reduces the carbon footprint of cement by 30%. This also has the added benefit of reducing the use of sand in concrete, which is increasingly becoming a limited resource.

The other type of concrete alternative replaces the clinker in the original cement. One proposal is to replace clinker from limestone with other materials, such as coal ash. This takes an existing waste stream and uses it to replace cement, up to 80% of it. This could be a good option for the next decade or two, but I hope that we will phase out coal power as quickly as possible, so this should not be a long term solution. But in the meantime, it can be one of many solutions.

Another approach is to inject CO2 into the concrete mixture when it is being made, instead of waiting decades for it to slowly absorb CO2. This potentially could create carbon neutral concrete.

The problem with all of these approaches, which all seem to work, is getting them up to industrial scale at a competitive cost. Of course, if any of these methods produced cheaper concrete at scale, then problem solved. But that is not the case. We can keep looking for a cheaper alternative, but it may be difficult to get cheaper than a process we have been doing for hundreds of years with an existing infrastructure. One approach is to consider the externalized cost of the carbon footprint of the cement industry. We could charge them for that cost by pricing carbon, making low carbon alternatives price competitive. Economists generally agree this is the best solution, but pricing carbon is a political heavy lift. Another approach is to subsidize the lower carbon but more expensive alternatives in some way. If this ultimately reduced climate change this is a good investment for public funds.

The post Let’s Talk About Cement first appeared on NeuroLogica Blog.

New books from Adrian Tchaikovsky and the late Michael Crichton (with James Patterson) are among the great new sci-fi novels out this month

The Dutch police force is already using a remotely controlled Spot robot dog made by Boston Dynamics to examine drug labs in raids, and now it wants to make the robot fully autonomous

The burgeoning use of wood as a building material is a path to more sustainable construction, and it may have psychological benefits too, finds Graham Lawton

A pair of Chinese taikonauts have completed an eight-hour spacewalk repairing damage to the Tiangong Chinese Space Station’s solar panels. It’s believed the damage was caused by tiny pieces of space debris, which impacted the solar wings and degraded their function. They performed a first repair spacewalk in December 2023 and completed the repairs with their second trip outside in March 2024. The Shenzhou 17 crew were the sixth group living in Tiangong and were relieved by the Shenzhou-18 team in late April.

The Shenzhou-18 mission, launched prior to the conclusion of Shenzhou-17, will last approximately six months. The crew, consisting of Ye Guangfu, Li Cong, and Li Guangsu, launched from the Jiuquan Satellite Launch Center aboard a Long March 2F rocket at 20h59 Beijing Time. Their spacecraft docked with the station’s Tianhe core module approximately six and a half hours after liftoff. On May 28, 2024, Ye Guangfu and Li Guangsu executed China’s longest spacewalk to date, lasting eight and a half hours, installing a space debris protection device on the station.

Senior Colonel Tang Hongbo and Lieutenant Colonel Jiang Xinlin completed nearly eight hours of extravehicular activity to repair damage to the Tianhe core module’s solar wings caused by impacts from tiny space debris. Lieutenant Colonel Tang Shengjie provided internal support throughout the operation, which marked the first instance of such a repair by Chinese taikonauts. This event, the 15th spacewalk conducted by Chinese astronauts, underscores the critical nature of maintaining the station’s integrity and safety. These operations are complex, but vital and require precise coordination and planning between the astronauts and ground control.

Although the term “spacewalk” is commonly used, the official term for when an astronaut ventures outside a spacecraft is Extravehicular Activity (EVA). The definition of an EVA can vary depending on the country conducting the operation. For instance, Russian and Soviet spacecraft designates an EVA as any instance where a cosmonaut spends time in a vacuum while in a space suit, using specialized airlocks for this purpose. In contrast, the American definition requires at least the astronaut’s head to be outside the spacecraft. Regardless of the definition, an EVA involves leaving the protective environment of the spacecraft and entering outer space, the area outside of Earth’s atmosphere. China made history as the third country to independently perform an Extravehicular Activity (EVA) on September 27, 2008, during the Shenzhou-7 mission. During this mission, Chinese taikonaut Zhai Zhigang completed a 22-minute spacewalk, fully exiting the spacecraft while wearing the Chinese-developed Feitian space suit. Taikonaut Liu Boming, dressed in the Russian-derived Orlan space suit, assisted Zhai by standing by at the airlock and straddling the portal.

The vacuum of space presents significant dangers due to its near complete lack of gas pressure. On Earth, our atmosphere, a mix of nitrogen, oxygen, and hydrogen gases, exerts a pressure of about 101 kilopascals at sea level, which our bodies are accustomed to. In space, however, the absence of pressure means that without a proper space suit, the air in an astronaut’s lungs would rapidly escape, and gases in body fluids would expand, causing severe internal damage. Additionally, astronauts face extreme temperatures, with sunlit objects reaching over 248 degrees Fahrenheit (120 degrees Celsius) and shaded areas dropping below negative 212 degrees Fahrenheit (negative 100 degrees Celsius). Furthermore, radiation from the sun, ultraviolet rays, and tiny meteoroids pose additional hazards.

To mitigate these risks, space suits are designed to maintain life support in the vacuum of space while allowing for sufficient mobility to perform tasks. These suits are essential for EVAs, providing the necessary protection against the harsh conditions of outer space. This advanced technology enables astronauts like those from the Shenzhou-17 crew to conduct critical repair operations and scientific experiments, ensuring the continued functionality and safety of missions aboard the Tiangong space station.

Since 2021, China has significantly advanced its space capabilities by conducting numerous extravehicular activities, each lasting several hours. These EVAs have been crucial for the construction and maintenance of the Tiangong space station.

During their time on the station, the Shenzhou-17 crew continued with planned space science experiments, technical tests, planned maintenance, and the installation of extravehicular payloads. Their tenure concluded with a handover to the incoming Shenzhou- 18 crew, ensuring the continuous operation of the Tiangong space station.

The recent repair and continued maintenance operations by both crews not only demonstrate China’s growing expertise in manned spaceflight but also highlight the collaborative and technical challenges of sustaining life and functionality in the harsh environment of space. The Tiangong space station is an important platform for research and technological advancement. The dedication of the Shenzhou crews, and the ongoing operational improvements in orbit pave the way for long term and sustained human activities far beyond our atmosphere.

The post Chinese Astronauts Just Repaired Space Debris Damage Outside the Station appeared first on Universe Today.

After many delays and two scrubbed launch attempts, Boeing’s CST-100 Starliner successfully launched earlier today! The Crewed Flight Test (CFT) took off from Space Launch Complex-41 at Cape Canaveral Space Force Station, Florida, at 10:52 a.m. EDT (07:52 PDT) atop a ULA Atlas V rocket. For this mission, the capsule is carrying two NASA astronauts: Barry “Butch” Wilmore (commander) and Sunita “Suni” Williams (pilot). They are expected to reach the International Space Station (ISS) at 12:15 p.m. EDT (09:15 a.m. PDT) on Thursday, June 6th.

Assuming all goes to plan, this mission will effectively validate the Starliner as part of NASA’s Commercial Crew Program (CCP). Then, we can expect it to make regular deliveries of cargo and crew to the ISS alongside SpaceX’s Crew Dragon spacecraft. This mission is the second time the Starliner has flown to the ISS and the third flight test overall. During the first test flight (OFT-1), which took place back in December 2019, the Starliner launched successfully but failed to make it to the ISS. After making 61 corrective actions recommended by NASA, another attempt was made (OFT-2) on May 22nd, 2022.

#Starliner ascends to the heavens!

Congratulations to @NASA, @BoeingSpace, and @ulalaunch. Today's launch is a milestone achievement for the future of spaceflight.

Butch and Suni—safe travels through the stars. See you back home.
pic.twitter.com/FYRzx7q4tN

— Bill Nelson (@SenBillNelson) June 5, 2024

Though two of the spacecraft’s thrusters failed during the flight, the spacecraft managed to reach the ISS and delivered 227 kg (500 lbs) of cargo. After nearly two years of delays, another attempt was made on June 1st, but the launch was scrubbed 3 minutes and 50 seconds before liftoff due to a faulty power supply. But, as they say, the third time is the charm! The launch was followed by a NASA news conference at the Kennedy Space Center in Florida, beginning at 12:30 a.m. EDT (09:30 a.m. PDT), which NASA live-streamed via NASA+, the NASA app, YouTube, and the agency’s website.

The conference was chaired by NASA Administrator Bill Nelson, Associate Administrator Ken Bowersox and Deputy Associate Administrator Joel Montalbano (NASA’s Space Operations Mission Directorate), Manager Steve Stitch and Mark Nappi (the manager and VP and program manager of CCP), and ULA president and CEO Tory Bruno. You can check out the recap here:

NASA+ will also cover the Starliner‘s approach to the ISS, starting at 09:15 a.m. EDT (06:15 PDT) on June 6th.

Further Reading: NASA

The post Starliner Finally Launches, Carrying Two Astronauts Into Orbit appeared first on Universe Today.

The European Space Agency has retired its Ariane 5 rocket, and all eyes are on its next generation, Ariane 6. The rocket’s pieces have been arriving at the Kourou facility in French Guiana and are now assembled.  ESA has now announced they’ll attempt a test launch on July 9th and hope to complete a second flight before the end of 2024. This new heavy-life rocket has a re-ignitable upper stage, allowing it to launch multiple payloads into different orbits.

“Ariane 6 marks a new era of autonomous, versatile European space travel,” said ESA Director General Josef Aschbacher, who announced the launch data at the Innovation and Leadership in Aerospace (ILA) Berlin Air Show on June 5, 2024. “This powerful rocket is the culmination of many years of dedication and ingenuity from thousands across Europe and, as it launches, it will re-establish Europe’s independent access to space. … I would like to thank the teams on the ground for their tireless hard work, teamwork and dedication in this last stretch of the inaugural launch campaign. Ariane 6 is Europe’s rocket for the needs of today, adaptable to our future ambitions.”

An overview of Europe’s new rocket, Ariane 6. Credit: ESA.

Ariane 6 has been in the works since the early 2010s to be a replacement the workhorse Ariane 5, which is no longer in production. Ariane 5’s first successful launch was in 1998, and since then has sent 109 spacecraft on their way, including the first ATV Jules Verne to the International Space Station and the James Webb Space Telescope to the second LaGrange point 1.5 million km (1 million miles) from Earth.

Ariane 6 is an expendable launch vehicle – not reusable like SpaceX’s rockets — that comes in two versions, with a modular design that can be customized: the rocket can use either two or four P120C strap-on boosters, depending on mission requirements. With the various designs, it can put a 4,500 kg payload into a geostationary transfer orbit or 10,300kg into low Earth orbit using the two boosters, and with four side boosters, it can launch 11,500 kg into a geostationary transfer orbit and 20,600kg into low Earth orbit. The re-ignitable upper stage allows for multiple satellites to launch on a single flight.

The Ariane 6 rocket test firing on its launch pad at the European Spaceport in French Guiana. Credit: ESA

Ariane 6 was developed at a cost of just under 4 billion euros ($3.9 billion) and was originally planned for its first launch in July 2020. However, the project has been hampered by several delays, including work-related issues during the Covid-19 pandemic.

The rocket has undergone several tests in the past few years, and in November of 2023, a full fueled Ariane 6 was tested on the launchpad, firing its engines for several minutes, simulating a flight to space.

“The announcement of the scheduled date for Ariane 6’s first flight puts us on the home stretch of the launch campaign and we are fully engaged in completing the very last steps,” said Martin Sion, CEO of ArianeGroup, the prime contractor of the Arian 6. “This flight will mark the culmination of years of development and testing by the teams at ArianeGroup and its partners across Europe. It will pave the way for commercial operations and a significant ramp-up over the next two years. Ariane 6 is a powerful, versatile and scalable launcher that will ensure Europe’s autonomous access to space.”

Part of the first Ariane 6 rocket inside the Vehicle Assembly Building, Kourou, French Guiana earlier in 2024. Credit: ESA/CNES/Arianespace/Arianegroup.

At the Spaceport in French Guiana, various payloads have been integrated on Ariane 6’s payload carrier. One major milestone must be met before launch: a full wet dress rehearsal, which is having a fully fueled vehicle going through all the steps of a countdown, but not the actual ignition of the rocket engines. Once this activity has been completed, the Ariane 6 Task Force will provide an update, confirming the date for the inaugural flight.

The post ESA Sets the Launch Date for Ariane 6: July 9th appeared first on Universe Today.

I have always wanted a 3D printer but never quite found a good enough reason to get one. Seeing that NASA are now 3D printing metal is even more tantalising than a plastic 3D printer. However, thinking about it, surely it is just a computer controlled soldering iron! I’m sure it’s far more advanced than that! Turns out that the first print really wasn’t much to right home about, just an s-curve deposited onto a metal plate! It does however prove and demonstrate the principle that a laser can liquify stainless steel and then deposit it precisely in a weightless environment. 

Arguably 3D printers have revolutionised manufacturing and prototyping industry.   The invention of them has been attributed to Chuck Hull who in 1983 but it’s more true to say he laid the foundations. Hull developed a technique known as stereolithography which involved creating 3D objects by curing thin layers of a photopolymer with UV light. The 3D printers that are commercially available came 5 years later in 1988.

NASA and ESA have been interested in 3D printing in space to make repair/improvement engineering far cheaper, sustainable and timely. Instead of waiting for parts to be shipped up to the ISS. To that end there has been a more conventional plastic 3D printer on board the ISS since 2014 because a 3D printed replacement is far simpler and more cost effective. Indeed ESA are trying to create a circular space economy to recycle materials already in orbit. It makes far more sense to repurpose existing materials in orbit – such as metal from old satellites – to make new tools or parts removing the need for rocket launches to transport them.

In November 2014, NASA astronaut Butch Wilmore installed a 3-D printer made by Made in Space in the Columbus laboratory’s Microgravity Science Glovebox on the International Space Station. Credit: NASA TV

The metal printer that is now on board the International Space Station employs stainless steel wire being fed onto the medium being printed upon. A high power laser which is a million times more powerful than a laser pointer then heats it up melting a small section. As the steel wire feeds into the melt pool it melts, adding to the metal, making it slightly raised. 

Unlike a 3D printer you may have (or I may be trying to justify) which you can control from your own computer, the printer on ISS is controlled entirely from the ground. The crew do have tasks however, they have to open a nitrogen and venting valve before the printing can start. I guess it’s almost the equivalent of putting the paper in your printer at home! 

The printer was developed by a team led by Airbus under the ESA Directorate of the Human and Robotic Exploration contract. It arrived on the ISS in January 2024 where the 180kg printer was installed in the ESA Columbus Module. 

The next step for the printer is to print four shapes that have been chosen for full-scale 3D printing. They will then be returned to Earth for analysis and comparison against reference prints already created in normal gravity. The teams hope to explore how microgravity impacts 3D printing. Two of the 3D printed parts will go to the Materials and Electrical Components Lab at ESTEC in Netherlands. The other two will go to the European Astronaut Centre at the Technical University of Denmark.

Source : First metal 3D printing on Space Station

The post Metal is 3D Printed on the Space Station appeared first on Universe Today.

People who stop taking antidepressants may get mental and physical symptoms as their bodies adjust to the lack of medicines - now we know how common this is

What is Dark Matter? That question is prominent in discussions about the nature of the Universe. There are many proposed explanations for dark matter, both within the Standard Model and outside of it.

One proposed component of dark matter is primordial black holes, created in the early Universe without a collapsing star as a progenitor.

The dark matter problem is a missing mass problem. Galaxies should not hold themselves together according to their observable mass. Their observable mass is stars, gas, dust, and a sprinkling of planets.

Some other form of mass must be present to prevent galaxies from essentially dissipating. Dark matter is a placeholder name for whatever that missing mass may be. Astronomer Fritz Zwicky first used the term in 1933 when he observed the Coma Cluster and found indications of missing mass. About 90% of the Coma Cluster is missing mass, which Zwicky called “dunkle Materie.”

This Hubble Space Telescope mosaic shows a portion of the immense Coma galaxy cluster that contains more than 1,000 galaxies and is located 300 million light-years away. The rapid motion of its galaxies was the first clue that dark matter existed. Image Credit: NASA, ESA, J. Mack (STScI) and J. Madrid (Australian Telescope National Facility

Primordial black holes (PBHs) are one leading candidate for dark matter. In the Universe’s earliest times, pockets of dense subatomic matter may have formed naturally. Once dense enough, they could’ve collapsed directly into black holes. Unlike their astrophysical counterparts, they had no stellar progenitors.

Recent JWST observations and LIGO/Virgo results support the idea that PBHs are dark matter. Some researchers go further and say that this evidence supports the idea that dark matter is exclusively made of PBHs and has no other components.

New research suggests that some of the early PBHs would merge and that LIGO/Virgo can detect the gravitational waves from mergers. The research is “Constraints on primordial black holes from LIGO-Virgo-KAGRA O3 events.” The lead author is M. Andres-Carcasona, a PhD student at the Institute of High Energy Physics at the Barcelona Institute of Science and Technology.

An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse into a black hole. Credit: Aaron Smith/TACC/UT-Austin.

In 2015, LIGO (Laser Interferometer Gravitational-Wave Observatory) detected its first black hole merger. At the time, researchers heralded this new window into the Universe. Until then, astronomical observations were based on electromagnetic radiation, but LIGO/Virgo changed that.

Now, Japan has joined the LIGO/Virgo collaboration with their Karga gravitational wave observatory, and the international effort is named LIGO/Virgo/Karga (LVK.) Together, the three observatories gather data on gravitational waves.

“Previous works have explored the use of GW data to find direct or indirect evidence of PBHs,” the authors write. “Specifically targeted searches of subsolar mass compact objects, which would provide a smoking gun signal of the existence of PBHs have so far been unsuccessful.”

The authors point out that within our growing body of GW data, there may be indications of PBHs that were missed by other researchers’ methods. They write that some of the component masses “… fall in regions where astrophysical models do not predict them, potentially suggesting for a PBH population,” they write.

This ESA graphic shows how we might discover primordial black holes and help solve the dark matter mystery using the JWST and LISA, the Laser Interferometer Space Antenna. Unfortunately, LISA’s launch is at least a decade away. Image Credit: ESA

The mass function of PBHs plays a large role in the formation of PBHs. Their goal is to update the mass constraints on PBHs in GW data. “One of our aims is to derive constraints which do not depend significantly on the underlying formation scenario. Thus, we consider a variety of different PBH mass functions,” they explain.

The two underlying formation scenarios they mention are astrophysical and primordial. Within the primordial category, there are different ways that PBHs can form, and they’re all tangled up with mass function. The authors explain that PBHs could explain the totality of dark matter, but only if they’re within the range of 10-16 to 10-12 solar masses.

“Lighter PBHs would be evaporating today and can constitute only a small portion of the DM,” they write.

Astrophysical BHs form binaries and can merge, sending out gravitational waves. If PBHs merge, they would also send out gravitational waves. It’s possible that some of these mergers are behind some of the GW data detected by LIGO/Virgo/Karga in its third observational run. The researchers present their results in terms of a pessimistic case and an optimistic case. The pessimistic case says that all GW observations are from Astrophysical Black Hole (ABH) mergers, while the optimistic case suggests that some are from PBH mergers.

Their research and its results involve an awfully large number of complicated physical terms and relationships. But the main question is whether PBHs can comprise dark matter, either partly or wholly. In that context, what do the results boil down to?

This artist’s illustration shows small black holes in the accretion disk of a supermassive black hole. In early 2024, a team of researchers found evidence of a small black hole inside the accretion disk of a supermassive black hole. The small BH, if it exists, is between 100 to 10,000 solar masses. At the bottom of that range, it’s the same mass as a PBH. It’s not thought to be primordial, but it indicates how much we’ve yet to learn about black holes. Credit: Caltech/R. Hurt (IPAC)

The researchers say that in their analysis of a population of both astrophysical and primordial binaries, PBHs cannot entirely comprise dark matter. At most, they can make up a small portion of it.

“… in a population of binaries consisting of primordial and astrophysical black holes, we find that, in every scenario, the PBHs can make up at most fPBH less than or equal to 10-3 of dark matter in the mass range 1-200 solar masses.”

fPBH represents the fraction of dark matter that PBHs can comprise, 10-3 means 0.001, and the solar mass range is self-explanatory. It doesn’t take a physicist to understand what they’re saying. PBHs can make up only a tiny fraction of dark matter in their analysis.

This may not be a headline-generating study. It’s a look under the hood of astrophysics and cosmology, where teams of researchers work hard to incrementally constrain and define different phenomena. But that doesn’t undermine its significance.

One day, there might be a headline that screams, “Physicists Identify Dark Matter! Universe’s Big Questions Answered!”

If that ever happens, hundreds and thousands of studies like this one will be behind it.

The post Primordial Black Holes Can Only Explain a Fraction of Dark Matter appeared first on Universe Today.

NASA are planning on building a telescope to hunt for habitable worlds. The imaginatively named ‘Habitable Worlds Observatory’ is at least a decade away but NASA have started to develop the underlying technology needed. The contracts have been awarded to three companies to research the next-generation optics, mission designs and telescope features at a cost of $17.5 million. Work should begin late summer 2024.

The Habitable Worlds Observatory (HWO) is a mission to launch a large space telescope with the main purpose of directly imaging Earth-like planets around stars like our Sun. It will also be able to study their atmosphere to look for chemical signatures for signs of life. The mission is very much in its early planning stages with working groups looking at the  science goals and how to achieve them. 

This is an artist’s illustration of the exoplanet TRAPPIST-1d, a potentially habitable exoplanet about 40 light-years away. Image Credit: By NASA/JPL-Caltech – Cropped from: PIA22093: TRAPPIST-1 Planet Lineup – Updated Feb. 2018, Public Domain, https://commons.wikimedia.org/w/index.php?curid=76364484

It is thought that, based on existing exoplanet research, one star in every five is likely to have an Earth-like planet in orbit around it. Of course the whole premise of searching for live in the Universe relies on that life being somewhat similar to our own. There may well be life based on a whole different chemistry but if we are to find life then we may as well look for life like ours rather thank take a punt on something completely different. To that end HWO will be on the lookout for chemicals like Oxygen and methane and other signatures that hint at the presence of life. 

In January of this year, NASA requested proposals that will drive and advance the necessary technologies that will be needed for HWO. This may sound a simple ask but taking into consideration what will be needed such as a coronagraph thousands of times more capable than existing to block out light from the host star and an optical system that can remain stationary to the accuracy of the width of an atom during an observation and you realise the challenges ahead. 

Following on from the first phase, NASA has now selected three proposals for two-year fixed price contracts that total a staggering $17.5 million. Sounds like a lot of money but Hubble cost $16 billion to develop and launch. The work is schedule to begin by late summer 2024. Together the contracts will deliver a framework of technology that will support the next phase of the HWO development and include;

• Modelling and sub-systems for an  ultra-stable’ optical system far beyond current capability. This will be delivered by BAE Systems.
• Develop necessary integrated modelling infrastructure that can navigate and compare design interdependencies. This element will be delivered by Lockheed Martin
• Advance the technologies need to support telescope operations such as deployable optical baffles to reduce stray light ingress and structural support for the optical train.  This final element will be delivered by Northrop Grumman.

Artist impression of the James Webb Space Telescope

NASA will of course be in control the whole way through and the output will enable them to plan for the development and build phase of the mission. The work is not being completed in isolation though as there are learnings from the James Webb Space Telescope and the future Nancy Grace Telescope too. 

Source : NASA Awards Advance Technologies for Future Habitable Worlds Mission

The post Research Work Begins on the Habitable Worlds Observatory appeared first on Universe Today.

I know:  the title sounds like a James Bond movie. . .

Over the last few years, the squirrels around Botany Pond have seemed to acquire a gene form that gives them golden tails. Now I don’t know if it’s a gene, but I don’t see how anything else can produce several squirrels with golden tails. (Not all of them have it.)

For your delectation, here are two shots of one I took on my way home. Since I always carry a stash of nuts in my bag for squirrels, this one got a pecan, and was delighted to have it.

If you’ve seen squirrels like this, or know how they develop this way, let me know.

Diabetes rates continue to rise. Scientists have now created a pain-free drug delivery method to help people with diabetes manage the disease and maintain their health more easily. Researchers have developed oral insulin drops that when placed under the tongue are quickly and efficiently absorbed by the body, potentially replacing the need for insulin injections.

The U.S. public displays more positive than negative sentiment toward nuclear energy but concerns remain about waste, cost and safety, according to an analysis of 300,000 posts on social media.

A single universal equation can closely approximate the frequency of wingbeats and fin strokes made by birds, insects, bats and whales, despite their different body sizes and wing shapes, researchers report in a new study.

Large Language Models behind popular generative AI platforms like ChatGPT gave different answers when asked to respond to the same reasoning test and didn't improve when given additional context, finds a new study.

New partitioning coefficients of first-transition row elements, Ga and Ge between olivine and silicate melt have been reported. New high-temperature experiments have investigated the effects of oxygen fugacity and iron content on these partition coefficients. This newly compiled dataset offers insights into interpreting trace elements found in olivine phenocrysts within lunar basalts, shedding light on the deep interior composition of the Moon.

Scientists are getting closer to detecting bushfires in record time, thanks to cube satellites with onboard AI now able to detect fires from space 500 times faster than traditional on-ground processing of imagery.