Watch the stars and from them learn. To the Master's honor all must turn, Each in its track, without a sound, Forever tracing Newton's ground

— Albert Einstein

Astronomy

SpaceX launches 22 Starlink satellites from California in dusky evening liftoff

Space.com - Mon, 03/18/2024 - 7:30pm
A SpaceX Falcon 9 rocket launched 22 more of the company's Starlink internet satellites to orbit tonight (March 18) from California.
Categories: Astronomy

Marvel Comics' new series celebrates Boba Fett's Mandalorian dad

Space.com - Mon, 03/18/2024 - 6:14pm
A preview of Marvel Comics' "Star Wars: Jango Fett #1," which is coming March 20.
Categories: Astronomy

Ep. 712: How Peer Review Fails

Astronomy Cast - Mon, 03/18/2024 - 5:00pm

You’ve probably heard that the best kind of science is peer-reviewed research published in a prestigious journal. But peer review has problems of its own. We’ll talk about that today.

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Categories: Astronomy

Track the April 8 total solar eclipse with SkySafari, now 80% off

Space.com - Mon, 03/18/2024 - 4:59pm
SkySafari 7 has a bundle of new features ahead of the next solar eclipse, and a big sale to match. It's all to get ready for the next solar eclipse in the United States on April 8.
Categories: Astronomy

Intermittent fasting linked to a higher risk of heart disease death

New Scientist Space - Space Headlines - Mon, 03/18/2024 - 4:00pm
Only eating within an 8-hour window is associated with a significantly higher risk of heart disease-related death compared with eating over 12 to 16 hours
Categories: Astronomy

Bad news for life on Mars? Red Planet's wet epoch may have been shorter than we thought

Space.com - Mon, 03/18/2024 - 4:00pm
Water freely flowed across Mars billions of years ago, suggesting the Red Planet could also once have supported life. But this water may have existed for just a short time.
Categories: Astronomy

Improving a 1960s Plan to Explore the Giant Planets

Universe Today - Mon, 03/18/2024 - 3:15pm

In the 1960s, NASA engineers developed a series of small lifting-body aircraft that could be dropped into the atmosphere of a giant planet, measuring the environment as they glided down. Although it would be a one-way trip to destruction, the form factor would allow a probe to glide around in different atmospheric layers, gathering data and transmitting it back to a parent satellite. An updated version of the 1960s design is being tested at NASA now, and a drop-test flight from a helicopter is scheduled for this month.

“We are looking to take an idea to flight and show that a lifting body aircraft can fly as a probe at this scale – that it can be stable, that components can be integrated into the probe, and that the aircraft can achieve some amount of lift,” said John Bodylski, the principal investigator at NASA’s Armstrong Flight Research Center in Edwards, California. Bodylski is working to prove that a lifting body aircraft design could meet the requirements for an atmospheric probe that could be used at giant planets, like Uranus or Jupiter.

Robert “Red” Jensen removes a major component from an aircraft mold for assembly of a prototype of an atmospheric probe as Justin Hall watches at NASA’s Armstrong Flight Research Center in Edwards, California. Credit: NASA/Steve Freeman

The idea behind the concept is that a lifting body aircraft relies on its unique blunt shape for lift, rather than wings. Bodylski and his team have designed two lifting body aircraft, both of which are about 70 cm (27 1/2 inches) long, and 60 cm (24 inches) wide. One is almost built and ready for flight.

NASA has a long history of doing flight tests with lifting bodies. From 1963 to 1975, NASA tested several designs to demonstrate the ability of pilots to maneuver and safely land a wingless vehicle. These vehicles included the M2-F1, M2-F2, HL-10, X-20, X-24A, and the X-24B. These lifting bodies were designed to validate the concept of flying a wingless vehicle back to Earth from space and landing it like an aircraft. The concept was influential in designing the Space Shuttle.

While the Space Shuttle and other human-carrying lifting body vehicles had inherent issues, even back in the 1960’s planetary scientists realized the concept could be more feasible for smaller uncrewed probes.

NASA says that current small atmospheric probes such as CubeSats, gather and transmit data for about 40 minutes and can take in approximately 10 data points before their parent satellite is out of range. Bodylski estimates this lifting body design could descend more rapidly and at a steeper angle, collecting the same information in 10 minutes, plus gather additional data for another 30 minutes from much deeper in a thick atmosphere.

The lifting body aircraft on Rogers Dry Lake, near what is now NASA’s Armstrong Flight Research Center in Edwards, California, include, from left, the X-24A, the M2-F3, and the HL-10. Credit: NASA

Lifting bodies have been in and out of vogue for decades. NASA actually had two designs for lifting bodies in the running as a precursor and later a successor to the Space Shuttle. The Dyna Soar was based on NASA’s X-20 lifting body and was designed to be launched by rocket into orbit, and the lifting body design would have allowed it to land like an airplane. Due to due to high costs, changing priorities for both the military and NASA – with the Apollo program just getting going — the Dyna Soar program was cancelled in December 1963, just before the first crewed test flight was scheduled for the following year.

Later, in 1996 NASA selected Lockheed Martin to build and fly the X-33 test vehicle to demonstrate advanced technologies for a new reusable spaceplane vehicle to succeed the Space Shuttle. Called VentureStar, it would have been a single-stage-to-orbit vehicle. However, NASA cancelled the project in 2001 before any test flights were carried out after some technical problems proved too difficult to solve.

More info on Bodylski’s project.

The post Improving a 1960s Plan to Explore the Giant Planets appeared first on Universe Today.

Categories: Astronomy

Blood-clotting drug derived from pigs can now be made synthetically

New Scientist Space - Space Headlines - Mon, 03/18/2024 - 3:00pm
A common anti-clotting drug called heparin is made from pig intestines, which risks contaminations and infections. A safer, synthetic version has now been developed but its production needs scaling up
Categories: Astronomy

New NASA astronauts 'thrilled' to see 1st Boeing Starliner crew launch in May (exclusive)

Space.com - Mon, 03/18/2024 - 3:00pm
A new NASA astronaut class finished training in March, just in time to watch a new spacecraft take flight. Boeing's Starliner is expected to fly its first crew to space in May.
Categories: Astronomy

As Extreme Heat and Smoke Threaten U.S. Farmworkers, Federal Health Leaders Evaluate Protections

Scientific American.com - Mon, 03/18/2024 - 2:30pm

Leaders of the Department of Health and Human Services will meet throughout the spring and summer to help protect farm laborers from heat and wildfire smoke

Categories: Astronomy

Scientists may finally know why this infamous supernova wears a 'string of pearls'

Space.com - Mon, 03/18/2024 - 2:00pm
SN 1987A is ringed by a strange string of hydrogen pearls that have puzzled astronomers for a long time, but researchers may finally have an explanation.
Categories: Astronomy

Finally, an Explanation for the “String of Pearls” in Supernova 1987A

Universe Today - Mon, 03/18/2024 - 1:41pm

Not long after the explosion of Supernova 1987a, astronomers were abuzz with predictions about how it might look in a few years. They suggested a pulsar would show up soon and many said that the expanding gas cloud would encounter earlier material ejected from the star. The collision would light up the region around the event and sparkle like diamonds.

Today, astronomers look at the site of the stellar catastrophe and see an expanding, glowing ring of light. Over the years, its shape has changed to a clumpy-looking string of pearls. What’s happening to affect its appearance? The answer lies in something called the “Crow Instability.” We see this aerodynamical process when vortexes off the wingtips of airplanes interact with the contrails from their engines. The instability breaks up the contrail into a set of vortex “rings”.

University of Michigan graduate student Michael Wadas says this type of instability could explain why Supernova 1987a formed a string of pearls. “The fascinating part about this is that the same mechanism that breaks up airplane wakes could be in play here,” said Wadas, who is now doing post-graduate work at CalTech. If that’s true, it will go a long way toward explaining why those ghostly pearls exist.

The expanding ring-shaped remnant of SN 1987A and its interaction with its surroundings, seen in X-ray and visible light. The star that became SN 1987a expelled concentric rings of material during its red and blue supergiant phases, and the shockwave from the supernova lit them up. Image: Public Domain, https://commons.wikimedia.org/w/index.php?curid=278848 About 1978a and its String of Pearls

Light and neutrinos from Supernova 1987a reached Earth on February 23, 1987. The original star, Sanduleak -69 202, lay about 168,000 light-years away in the Large Magellanic Cloud. It exploded as Type II, the first one in modern times to show astronomers the details of a core-collapse supernova. Since then, astronomers watched as a ring of ejected material and a shockwave from the explosion itself spread to space. It slammed into the material shed earlier in the star’s life. It does have a neutron star in the center. Astronomers detected it in 2019 and observed it using X-ray and gamma-ray observatories.

Several months after the explosion, astronomers used the Hubble Space Telescope to image bright rings surrounding the explosion site. That material came from the stellar wind of the progenitor star. Ultraviolet light from the explosion ionized the gases in the cloud. The inner ring lay about 2/3 of a light-year from the original star. The expanding ejecta from the supernova eventually collided with it in 2001. That heated it further. The shockwave has now expanded beyond the rings, leaving behind pockets of warm dust and glowing clouds of gas. The turbulence of that shockwave and the damage it did to regions of the inner ring is created the “pearls”.

Competing Theories for the String

So, what physics underlies the appearance of the pearls? Astronomers have tried to explain the string using something called a Rayleigh-Taylor instability. That occurs when two fluids (or plasmas) of different densities interact with each other. Think of oil and water trying to mix, or a heavy pyroclastic flow streaming out of a volcano. The interaction forms interesting and predictable shapes in the fluids. For 1978a, the denser “fluid” is the material ejected during the supernova explosion. It is colliding with a less dense cloud of material ejected earlier that has spread out to space. However, there are issues with using the Rayleigh-Taylor instability to explain what we see at the supernova site.

A simulation shows the shape of the gas cloud on the left and the vortices, or regions of rapidly rotating flow, on the right. Each ring represents a later time in the evolution of the cloud. The gas cloud starts as an even ring with no rotation. It becomes a lumpy ring as the vortices develop. Eventually, the gas breaks up into distinct clumps. Credit: Michael Wadas, Scientific Computing and Flow Laboratory

“The Rayleigh-Taylor instability could tell you that there might be clumps, but it would be very difficult to pull a number out of it,” said Wadas, who suggested the Crow Instability in a paper just published in Physical Review Letters. Jet contrails are a better comparison because the wingtip vortices break up the long smooth line of a jet contrail. The vortices flow into each other, leaving gaps that can be predicted.

To explore that idea, Wadas and his colleagues simulated the way winds push a model cloud outward while also dragging on its surface. The top and bottom of the cloud got pushed out faster than the middle. That caused it to curl in on itself, triggering a Crow Instability that broke the cloud apart into 32 even clumps similar to the string of pearls at 1987a (which has 30-40 clumps). That predictable number of clumps is why the team suggested the Crow Instability as a formation agent for the string. They also think it could help predict the formation of more beaded rings around the explosion site or when dust around a star coalesces to form planets. Recent JWST infrared images seem to show even more clumps that have appeared in the ring, and it will be interesting to see if more of them appear in the future.

For More Information

Explaining a Supernova’s “String of Pearls”
Hydrodynamic Mechanism for Clumping along the Equatorial Rings of SN1987A and Other Stars

The post Finally, an Explanation for the “String of Pearls” in Supernova 1987A appeared first on Universe Today.

Categories: Astronomy

SpaceX's Starship will go interstellar someday, Elon Musk says

Space.com - Mon, 03/18/2024 - 1:30pm
A future, more advanced version of SpaceX's Starship megarocket will travel to other star systems, according to Elon Musk.
Categories: Astronomy

People with ‘Havana Syndrome’ Show No Brain Damage or Medical Illness

Scientific American.com - Mon, 03/18/2024 - 1:30pm

The largest and most comprehensive studies of ‘Havana Syndrome’ point to stress or group psychology as likely explanations for most “anomalous health incidents”

Categories: Astronomy

Why People Aged 65 and Older Should Get a Spring COVID Vaccine

Scientific American.com - Mon, 03/18/2024 - 1:00pm

Older people are particularly vulnerable to COVID and should get another vaccine against the disease this spring, doctors say

Categories: Astronomy

Thomas Stafford, NASA astronaut who led Apollo-Soyuz joint mission, dies at 93

Space.com - Mon, 03/18/2024 - 12:59pm
Former NASA astronaut Thomas Stafford, who flew to the moon before leading the first international space mission carried out by the United States and Russia, has died at the age of 93.
Categories: Astronomy

NASA is Working on Zero-Boil Off Tanks for Space Exploration

Universe Today - Mon, 03/18/2024 - 12:10pm

No matter what mode of transportation you take for a long trip, at some point, you’ll have to refuel. For cars, this could be a simple trip to a gas station, while planes, trains, and ships have more specialized refueling services at their depots or ports. However, for spacecraft, there is currently no refueling infrastructure whatsoever. And since the fuel spacecraft use must be stored cryogenically, and the tanks the fuel is stored in are constantly subjected to the thermal radiation from the Sun, keeping enough fuel in a tank for a trip to Mars with astronauts is currently infeasible. Luckily, NASA is currently working on it and recently released a detailed look at some of that work on a blog on their website.

The problem definition is very clear – cryogenic hydrogen and oxygen are used as fuel on most spacecraft missions. Once in space, the tanks the fuel is stored in heat up due to the constant solar radiation they’re subjected to. Since there’s no air, there’s no way to radiate out that heat, so eventually, it can get through even the most sophisticated passive thermal insulation system. When it does, the fuel starts to boil, and mission planners typically have chosen to eject the vaporous fuel out into space rather than leaving it as a potential medium to heat the rest of the fuel faster.

This resultant fuel lost to this sublimation can cost as much as half of the cryogenic fuel needed for a 3-year mission to Mars – in just a single year. In short, crewed trips to Mars are impossible using the current fuel storage technology in space. However, there are alternatives, known as Zero Boil-Off (ZBO) or Reduced Boil-Off (RBO) systems. These advanced tanks use a combination of “active” processes to maintain tank pressure and not allow too much loss of fuel during long space flights.

Fraser makes an argument for why refueling is so critical.

An “active” process must be actively controlled and typically requires some sort of power input. In particular, ZBO systems rely on two technology ideas – a jet mixing of the propellant and a droplet injection technology. Let’s take a look at the mixing technology first.

In this example, part of the fuel would be forcibly mixed back into the vapor space in a particular way that would allow it to control the phase changes of the vapor/fuel interface. In essence, it would stop the fuel from sublimating into a vapor in the first place. Similarly, a droplet injection system would use a novel type of spray bar to inject fuel droplets into the vapor area, causing it to condense and remove some of the pressure from the system.

To add another layer of complexity to these already complicated fluid dynamics systems, this all must be done in microgravity, where things like droplet formation and liquid mixing don’t always happen the same way as they do on Earth. So, NASA decided to do what it does best and run some experiments – in this case on the ISS.

Image of the ZBOT-1 experiment being installed on the ISS by astronaut Joseph Acaba.
Credit – NASA

Back in 2017, NASA started the ZBOT-1 Experiment on the ISS. It was intended to quantify how the jet mixing would behave in microgravity, and the result of some 30+ tests was that we still understand very little about how these systems work in microgravity. While how they were is different than what most fluid engineers are used to, they are still acting according to physical laws, so more experiments would help narrow down the models that tank designers can use to understand how these ZBO systems might best be used.

Two other experiments are focused on furthering that understanding – one called the ZBOT-NC Experiment, is due to be launched to the ISS in 2025. It will study the effects of microgravity on “non-condensable gases,” which can be used to control the pressure inside the fuel tank. Data from its observations can also be fed into the CFD models, allowing scientists to understand better how the model differs from reality in microgravity.

The final test in the series will focus on droplet phase changes. Known as the ZBOT-DP test, this is the most ambitious of the three, as it tests a technology that has never been used in microgravity at all before. It will focus on understanding how droplets interact with their surroundings, including superheated tank walls, in microgravity environments. They could eventually lead to a fully functional droplet system and an active control system to ensure no tank boil-off happens.

The idea of in-space refueling has been around for a long time, as this VideoFromSpace feature shows.
Credit – VideosFromSpace YouTube Channel / NASA Technology

That’s still a long way off those, with no planned date for the ZBOT-DP test. Given the importance of this technology to missions like the crewed Artemis mission planned in the next few years, it seems that the successful completion of these experiments and the design and testing of a fully ZBO fuel tank should be very high on NASA’s priority list. While the agency’s already supporting it, let’s hope that the researchers involved can prove their ideas before they’re needed for a real human mission.

Learn More:
NASA – Zero-Boil-Off Tank Experiments to Enable Long-Duration Space Exploration
UT – Why Build Big Rockets at All? It’s Time for Orbital Refueling
UT – There’s Now a Gas Station… In Space!
UT – Robotics Refueling Research Scores Huge Leap at Space Station

Lead Image:
The Gateway space station—humanity’s first space station around the Moon—will be capable of being refueled in space.
Credits: NASA

The post NASA is Working on Zero-Boil Off Tanks for Space Exploration appeared first on Universe Today.

Categories: Astronomy

Mysterious 'unparticles' may be pushing the universe apart, new theoretical study suggests

Space.com - Mon, 03/18/2024 - 12:00pm
New theoretical research suggests that a mysterious form of matter called "unparticles" could be the driving force behind the expansion of the universe.
Categories: Astronomy

Mammoth carcass was scavenged by ancient humans and sabre-toothed cats

New Scientist Space - Space Headlines - Mon, 03/18/2024 - 12:00pm
A southern mammoth skeleton found in Spain bears cut marks from stone tools and bite marks from carnivore teeth, suggesting that both hominins and felids feasted on its meat
Categories: Astronomy

Mammoth carcass was scavenged by ancient humans and sabre-toothed cats

New Scientist Space - Cosmology - Mon, 03/18/2024 - 12:00pm
A southern mammoth skeleton found in Spain bears cut marks from stone tools and bite marks from carnivore teeth, suggesting that both hominins and felids feasted on its meat
Categories: Astronomy