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After a Boost from Earth and the Moon, Juice is On its Way to Venus and Beyond
The first spacecraft to use gravity assist was NASA’s Mariner 10 in 1974. It used a gravity assist from Venus to reach Mercury. Now, the gravity assist maneuver is a crucial part of modern space travel.
The latest spacecraft to use gravity assist is the ESA’s JUICE spacecraft.
The European Space Agency (ESA) launched its JUICE spacecraft on April 14, 2023. Its eventual destination is the Jovian system and its icy moons, Europa, Callisto, and Ganymede. But it’s a long journey, and the spacecraft took a shortcut by travelling close to Earth and the Moon and using their gravity to gain momentum and change trajectory.
It’s the first spacecraft ever to use the Earth and the Moon for a gravitational slingshot, and it captured some images to share with us.
JUICE stands for Jupiter Icy Moons Explorer, and it’s on a mission to study three moons with suspected oceans buried under layers of ice. It’s got a long way to go, and on long-duration missions, economical use of propellant is critical. This Earth-lunar slingshot maneuver is all about saving propellant.
“The gravity assist flyby was flawless, everything went without a hitch, and we were thrilled to see Juice coming back so close to Earth,” says Ignacio Tanco, Spacecraft Operations Manager for the mission.
At its closest approach to Earth, JUICE passed overhead of Southeast Asia and the Pacific Ocean at only 6840 km (4250 miles) altitude. It was a risky maneuver but one that saved the mission between 100 and 150 kg of propellant.
This lunar-Earth flyby isn’t JUICE’s only gravity-assist maneuver. Next August, it will slingshot past Venus, and on September 26th and January 2029, it will slingshot past Earth. All these gravity-assist maneuvers will give JUICE momentum for its journey to Jupiter. JUICE will reach Jupiter in 2031, and because of all of these maneuvers it will have more propellant left when it gets there.
JUICE has completed its first gravity-assist maneuver and, in one year, will perform another one with Venus. Credit: ESA. Acknowledgements: Work performed by ATG under contract to ESA. Licence: CC BY-SA 3.0 IGO“Thanks to very precise navigation by ESA’s Flight Dynamics team, we managed to use only a tiny fraction of the propellant reserved for this flyby. This will add to the margins we keep for a rainy day, or to extend the science mission once we get to Jupiter,” said Ignacio Tanco, Spacecraft Operations Manager for the JUICE mission.
Modern orbiters bristle with science instruments, antennae, and cameras. JUICE is no exception. Among all its instruments and science cameras, it carries two monitoring cameras called JMCs, or JUICE Monitoring Cameras. They’re 1024×1024 pixel cameras with different fields of view. Their job is to monitor the spacecraft’s booms and antennae, and their job was especially critical when they were deployed after launch.
The ESA’s Jupiter Icy Moons Explorer has two Juice Monitoring Cameras, or JMCs, to provide snapshots with different fields of view. Their main job is to monitor components of the spacecraft, but they captured images of Earth and the Moon during the recent flyby. Image Credit: ESA (acknowledgement: work performed by ATG under contract to ESA) LICENCE: CC BY-SA 3.0 IGODuring the flyby, JUICE used its JMCs to capture images of the Earth and the Moon.
JUICE Monitoring Camera 2 captured this image of the Moon as it flew past it on August 10th. “A closer look reveals a casual ‘photobomber’ – Earth shows itself as a dark circle outlined by a light crescent at the top centre of the image, peeking out from behind the spacecraft structure (look just above the fuzzy blue blob, which itself is a ghost image caused by the reflection of sunlight),” the ESA writes. CREDITESA/Juice/JMC. ACKNOWLEDGEMENTS: Simeon Schmauß & Mark McCaughrean. LICENCE: CC BY-SA 3.0 IGO
It also used eight of its ten instruments to collect scientific data from Earth and all ten for the Moon.
“The timing and location of this double flyby allows us to thoroughly study the behaviour of Juice’s instruments,” explains Claire Vallat, Juice Operations Scientist.
JMC 1 captured this image of the Moon during the lunar flyby. CREDIT: ESA/Juice/JMC. ACKNOWLEDGEMENTS: Simeon Schmauß & Mark McCaughrean. LICENCE: CC BY-SA 3.0 IGOJUICE’s main science camera is JANUS, a high-resolution optical camera. Its role is to capture detailed images of the surface of Ganymede, Callisto, and Europa. The JUICE team used JANUS to capture more than 400 preliminary views of the Earth and the Moon.
“After more than 12 years of work to propose, build and verify the instrument, this is the first opportunity to see first-hand data similar to those we will acquire in the Jupiter system starting in 2031,” says Pasquale Palumbo, a researcher at INAF in Rome and principal investigator of the team that designed, tested and calibrated the Janus camera.
The Moon’s pockmarked surface as revealed by JANUS. Image Credit:“Even though the flyby was planned exclusively to facilitate the interplanetary journey to Jupiter, all the instruments on board the probe took advantage of the passage near the Moon and Earth to acquire data, test operations and processing techniques with the advantage of already knowing what we were observing,” said Palumbo.
Earth was imaged at dawn on August 20, 2024, by the JANUS optical camera aboard JUICE. The image shows the island of Hawai’i (the dark spot on the left), the largest island in the Hawaiian archipelago in the central Pacific of the United States. The view is very low, after a short while the Earth left the field of view of JANUS. Credits: JANUS team (INAF, ASI, DLR, CSIC-IAA, OpenUniversity, CISAS-Università di Padova and other international partners)These early-mission images are whetting our appetite for when the real fun starts in seven years. JUICE will reach the Jovian system in July 2031 and will do 35 flybys of the gas giant’s icy moons. Then, in December 2034, it will enter orbit around Ganymede.
There is growing evidence that Europa, Ganymede, and Callisto have warm, salty oceans buried under thick layers of ice. These are prime targets in our search for life. But, maddeningly, we don’t know for sure if they could support life or even if the oceans are real.
Hopefully, JUICE can tell us. But it can’t do that without these risky, early-mission maneuvers.
The post After a Boost from Earth and the Moon, Juice is On its Way to Venus and Beyond appeared first on Universe Today.
Another blow for dark matter as biggest hunt yet finds nothing
How the healing powers of botany can reduce anxiety and boost health
First low frequency search for alien technology in distant galaxies
Astrophysicists use AI to precisely calculate universe's 'settings'
Astrophysicists use AI to precisely calculate universe's 'settings'
Early galaxies were not too big for their britches after all
Bicycle rolling-stop laws don't lead to unsafe behavior by riders or motorists, research shows
New record in search for dark matter
New record in search for dark matter
X-Ray Telescopes Could Study Exoplanets Too
Exoplanets are often discovered using the transit method (over three quarters of those discovered have been found this way.) The same transit technique can be used to study them, often revealing detail about their atmosphere. The observations are typically made in visible light or infrared but a new paper suggests X-rays may be useful too. Stellar wind interactions with the planet’s atmosphere for example would lead to X-ray emissions revealing information about the atmosphere. As we further our exploration of exoplanets we develop our understanding of our own Solar System and ultimately, the origins of life in the Universe.
The first planet around another star was confirmed in 1992. Since then, astronomers around the world have discovered thousands of exoplanets with many differences. Some are gas giants like Jupiter, others small and rocky more like the Earth. Their positions too vary from their host star with some tantalising orbiting within the habitable zone, the region where liquid water is a distinct possibility. Most discoveries are in the visible spectrum but using X-ray telescopes has opened up a new window in our hunt for, and understanding of alien worlds.
“Icy and Rocky Worlds” is a new exoplanet infographic by Slovak artist and space enthusiast Martin Vargic. It’s available as a wall poster at his website. Image Credit and Copyright: Martin VargicMost of the exoplanets that have been discovered using visible light tend to be on short period orbits and, as a result of their proximity to their host star, are subject to high levels of radiation. These levels of radiation are often in the X-ray and extreme ultraviolet range and they heat the upper levels of the planet’s atmosphere. The result is that the atmosphere expands beyond the radius where the gravitational pull can keep hold of it and so gasses are lost into space.
It is interesting that such a phenomenon offers some interesting areas for study such as the lack of planets in the 1.5 – 2 Earth radii range and of Neptune sized planets on orbits of 10 days period or less. It has been suggested that the loss of atmospheric gasses explains the scarcity of Neptune sized planets on close orbits. The so-called sub-Neptunes however which have rocky cores have a higher gravitational force so they are able to hang on to their atmospheres despite their close proximity to the star. Studying exoplanet atmospheres should go some way to understand these processes in greater detail.
X-ray transit events are the perfect way to study X-ray emissions from exoplanet transits. They events are however quite faint making X-ray observations difficult with current technology. A team of astronomers from the University of Michigan led by Raven Cilley have published a paper exploring the capability of future x-ray observatories (such as NewAthena and Advanced X-ray Imaging Satellite – AXIS) in detecting more transit events.
By combining a large X-ray telescope with state-of-the-art scientific instruments, Athena will address key questions in astrophysics. Credit: ESAUsing data from NASA’s Exoplanet Archive, the team first found targets which were missing X-ray observations and estimated X-ray luminosity from age, colour and rotation. The transits were modelled as they would appear in AXIS and NewAthena observations and determined the probability of each transit to be detectable using simulated light curves. The team found that their top 15 transits were likely to be detected but only if multiple light curves were stacked. Those exoplanets were there was an absence of atmospheric escape were less likely to be detected.
The findings showed that exoplanet transit X-ray detection likelihood increases substantially with new technology like AXIS and NewAthena. The enhanced capability will lead to an improved understanding of exoplanetary atmosphere properties in their current and prior states, also improving our chances in the hunt for habitable worlds.
Source : Detecting exoplanet transits with the next generation of X-ray telescopes
The post X-Ray Telescopes Could Study Exoplanets Too appeared first on Universe Today.
We can diagnose an object’s quantumness from the way it radiates heat
Life Needs Black Holes to Survive
Life is rare, and it requires exactly the right environmental mix to establish itself. And there’s one surprising contributor to that perfect mix: gigantic black holes.
Life requires a certain combination of elements to make itself possible: hydrogen, nitrogen, carbon, oxygen, phosphorus, and sulfur. Hydrogen has been hanging around the universe since the first few minutes of the big bang, but the other elements only come from fusion processes inside of stars. Galaxies need several generations of stellar lives and deaths before a solar system like our own can be possible.
But left to its own devices, star formation in a galaxy can proceed far too rapidly, burning through material too quickly, the stellar generations coming and going in a blink. One thing that can put the brakes on this kind of out-of-control star formation is the activity tied to supermassive black holes.
Giant black holes sit in the hearts of almost every single galaxy. Their intense gravitational strength can pull material towards it. The swirl and turbulence of gas will send material careening towards the galactic center, where the waiting black hole is more than eager to devour it. As the gas crams itself down the throat of the vent horizon, it will heat up to over a trillion degrees, releasing a flood of high-energy radiation in the process.
That radiation floods the rest of the galaxy, heating up the rest of the gas. To make stars, the gas in a galaxy has to be cool, allowing it to collapse to high densities. But if it’s heated by outbursts from the central black hole, it can’t make new stars. After enough time, however, the gas cools off and resumes star formation, and the entire cycle starts again.
This feedback process from the central black hole keeps star formation in a galaxy regulated. Without the black hole, galaxies would use up their available material much quicker, possibly before the ingredients needed for life can circulate and spread throughout the galaxy.
So the next time you take a deep breath and feel grateful you’re alive, thank a supermassive black hole.
The post Life Needs Black Holes to Survive appeared first on Universe Today.
Superconducting Kagome Metals
Superconductivity is an extremely interesting, and potentially extremely useful, physical phenomenon. It refers to a state in which current flows through a material without resistance, and therefore without any loss of energy or waste heat. As our civilization is increasingly run by electronic devices, the potential benefit is huge.
As physicists unravel the quantum physics of superconductivity, this allows them to potentially design new materials that can display superconductivity in useful settings. One recent study presents a small breakthrough in a specific type of superconducting material – Kagome metals. These are a class of ferromagnetic metal metamaterials with an interwoven structure that resembles the Japanese basket by the same name. This creates some specific quantum effects that are currently being researched for their technological uses, one of which is superconductivity.
One of the ways in which superconductivity arises is through what are known as Cooper pairs – two electrons that join together in a quantum state that distributes them like a wave throughout the material. Cooper pairs can therefore “travel” through a material without resistance. A recent study looks at the formation of Cooper pairs within Kagome metals, showing something surprising to physicists. Previously it was believes that Cooper pairs were evenly distributed within Kagome metals. The new study finds that the number of Cooper pairs in the star-point locations with the Kagome pattern can contain a variable number of Cooper pairs.
This was predicted in 2023 by Professor Ronny Thomale. His predictions have now been verified by direct observation, changing how physicists think about the superconducting potential of Kagome metals. You can read the study if you want to delve deeper into the details, but let’s talk a bit about the technological potential.
First, like other superconducting material, Kagome superconductors require extremely low temperature, -272 C. Cooper pair generally are a phenomenon that happens at very low temperatures, and much of the research into superconductivity has been searching for materials in which Cooper pairs form and superconductivity happens at higher temperatures. The current record (for ambient pressure) is a cuprate of mercury, barium, and calcium, at around 133 K (−140 °C). A big breakthrough happened in the 80s when a class of ceramics was discovered with superconducting temperature above that of liquid nitrogen. Liquid nitrogen is relatively cheap, allowing for the practical development of devices operating at this temperature (like the superconducting supercollider, and the magnets used in plasma research for fusion).
Another class of material becomes superconducting at high temperature but at super high pressures, making them completely impractical for actual use. This research is mostly about understanding superconductivity, not necessarily developing usable superconducting material. I of course have to wonder if the research with Kagome metals is similar – improving our understanding of the underlying physics, but not necessarily a pathway to usable materials. That remains to be seen.
Of course, the press release emphasizes the potential applications – because they always (or at least almost always) do that. That’s the formula with any new material science research – what’s the sci fi tech application. Then lead with that. So I take any such discussion with a grain of salt. Still, we can explore what potential applications would look like, and if not with this exact material, then something similar.
For Kagome metals, it seems applications would be limited to things that are physically small. I don’t think this is the material we will be making superconducting cables out of. In fact the current observations are only at the atomic scale, not the macroscopic scale. But they could be useful tiny electronic components, such as diodes. The obvious application would be in computers, including quantum computers.
The potential benefit of superconducting components in computers should not be underestimated. Increasingly we are building huge data centers for multiple applications, with artificial intelligence apps likely to significantly increase the need for hardware. These data centers use massive amounts of energy, measure on the scale of major industrialized nations, and increasing. They also generate a great deal of heat, and therefore have to spend more energy for cooling.
Now imagine a data center with computers that have mostly superconducting components, using a fraction of the energy and producing little waste heat. Even if you had to supercool the entire thing with liquid nitrogen temperatures, it would likely be worth it.
But of course, the higher temperature the superconductors, the more cost-effective and practical they are. If such a data center needed to be merely refrigerated, to -40 C for example, that would be relatively easy and cost effective. The ultimate goal of superconducting research, of course, is the “room temperature” (ambient pressure) superconductor. It’s not clear if this is even physically possible – right now we have no theory of how a room temperature superconductor would work, but no one has proven that they are impossible either. They remain theoretical. This is the real promise of superconducting research, even if the approach does not lead directly to a specific application. The more we understand about the quantum physics of superconducting, the better we will be able to design and research new materials at higher temperatures.
I don’t know if we will see superconducting Kagome metal-based technologies in the future. We may or may not. But at least we have added on more piece of the puzzle to our understanding of superconductivity.
The post Superconducting Kagome Metals first appeared on NeuroLogica Blog.
Stanford University will host a conference on pandemic planning featuring the usual (COVID-19) suspects
This week, Stanford University announced a conference on pandemic policy that features several of the usual suspects who spread misinformation during the COVID-19 pandemic. Truly, Stanford has become the "respectable" academic face of efforts to undermine public health.
The post Stanford University will host a conference on pandemic planning featuring the usual (COVID-19) suspects first appeared on Science-Based Medicine.Monday: Hili dialogue
Meanwhile, in Dobrzyn, Hili is getting spiritual:
A: What are you doing?
Hili: I’m thinking about evanescence.
Ja: Co robisz?
Hili: Myślę o przemijaniu.
The Big Fringe Telescope. A 2.2 KILOMETER Telescope on the Cheap. And it Can Make Exoplanet “Movies”.
Can a kilometer-scale telescope help conduct more efficient science, and specifically for the field of optical interferometry? This is what a recently submitted study hopes to address as a pair of researchers propose the Big Fringe Telescope (BFT), which is slated to comprise 16 telescopes 0.5-meter in diameter and will be equivalent to a telescope at 2.2 kilometers in diameter. What makes BFT unique is its potential to create real-time exoplanet “movies” like the movies featuring Venus transiting our Sun, along with significantly reduced construction costs compared to current ground-based optical interferometers.
This proposal builds upon past optical interferometers, including Georgia State University’s Center for High Angular Resolution Astronomy (CHARA) array comprised of six telescopes 1-meter in diameter equivalent to a telescope 330 meters in diameter, and the European Southern Observatory’s Very Large Telescope Interferometer (VTLI) comprised of four 8.2-meter telescopes and four movable 1.8-meter telescopes equivalent to a telescope 130 meters in diameter. Additionally, this proposal comes as the ESO is currently building its Extremely Large Telescope with a 39.3-meter-diameter (130-foot) reflecting telescope in the Atacama Desert in Chile.
Here, Universe Today discusses this incredible proposal with Dr. Gerard van Belle, who is an astronomer at the Lowell Observatory in Flagstaff, Arizona, regarding the motivation behind proposing BFT, the science cases that BFT hopes to accomplish, new methods regarding how BFT will study exoplanets (i.e., real-time movies), how BFT can potentially contribute to finding life beyond Earth, the next steps for making BFT a reality, and the implications for each telescope being 0.5 meters in diameter for both the science and cost. Therefore, what was the motivation behind proposing BFT?
“The motivation is that somewhere along the line, the community ended up ‘leaving money on the table’,” Dr. van Belle tells Universe Today. “There’s a really exciting science case here – imaging of bright stars – and it’s been overlooked. This is in part because the collective imagination of the people (like me) who build these very high angular resolution imaging arrays has been collectively distracted by pushing on going ‘fainter, fainter, fainter’, rather than ‘finer, finer, finer’. And the nice surprise is that, since we’re not going super faint, the telescopes that make up the BFT array are small, and therefore the BFT is surprisingly affordable. The additional third axis here is much of the parts are only recently commercial-off-the-shelf, so that also helps the affordability. So, it’s great science that hasn’t been done, it’s cheap, and it’s timely.”
The study notes that the “routine imaging of bright main sequence stars remains a surprisingly unexplored scientific realm.” For context, while the CHARA array obtained the first image of a single, main-sequence star in 2007, some of the science conducted by CHARA has focused on binary stars, supernova explosions, and dust orbiting stars. Additionally, while the VLTI obtained the best image of the surface and atmosphere of a red supergiant star, some of the science conducted included direct observations of exoplanets, observing Sagittarius A*, which is the supermassive black hole at the center of the Milky Way, and detection of exozodiacal light. Like CHARA and VLTI, the BFT will also conduct a wide range of science along with its goal of imaging bright, main-sequence stars. These include studying exoplanet host stars, solar analogs, resolved binaries, and resolved exoplanet transits.
Dr. van Belle tells Universe Today, “The exoplanet hosts are the real meat-and-potatoes case here: the explosion of discoveries over the past three decades on exoplanets has really transformed astronomy. Solar analogs are super important to study. Up until now, we have a single solar-like star we can resolve into more than a disk and see how it behaves over time – namely, our own sun. But that’s a little like trying to learn anatomy and physiology if you were a doctor to a single patient, ever. So, being able to make resolved images of sun-like stars is really vital to better understanding our own sun – and especially its effect on our home planet.”
Dr. van Belle continues, “Observations of binary star systems let us determine the masses because of their orbital motion around each other, and BFT adds extra value by then directly measuring the radii of those stars. Resolved exoplanet transits is going to be the wicked cool one. We will be able to see the *resolved* disk of *another world* as it passes in front of its host star. This sort of thing will be good for further characterization of exoplanets, as well as searches for exomoons. There’s a bunch of other BFT science that isn’t part of the core ‘marquee’ cases – many hundreds of different types of stars that we’ll be able to make pictures of and see how those pictures change over time.”
Currently, directly viewing exoplanets is obtained through the direct imaging method where astronomers use a coronagraph to blot out the glare of a host star, revealing the hidden exoplanets underneath, although their full shapes aren’t observable. Additionally, the transit method is conducted by measuring the dip in starlight caused by the exoplanet traveling in front of it but is not observable due to their small size and the intense glare of the host star.
The resolved exoplanet transits that BFT hopes to achieve means astronomers will be able to observe the full outline of an exoplanet as it passes in front of its host star, thus combining the direct imaging method with the transit method. An example of this is when Venus passes in front of our Sun, enabling astronomers to observe the entire outline of both the planet and our Sun, resulting in real-time movies of this incredible astronomical event. With BFT, these real-time movies are anticipated to be made for exoplanets, as well. Therefore, what science can be achieved from these real-time movies?
“As noted above, we’ll be able to see these worlds as resolvable disks,” Dr. van Belle tells Universe Today. “That’ll let us better pin down the linear size, as well as measure the density of these worlds – eg. rocky or watery, solid or gaseous? Doing such resolving in a wavelength-dependent sense may tell us about the composition of the atmospheres, too – though that’s a pretty challenging observation. Maybe the more straightforward thing will be attempting to measure the oblateness of the gaseous worlds – eg. Jupiter is a bit wider than it is tall, because of it being a rapidly spinning clot of gas. Such observations will allow us to measure the rotation rate of those planets.”
As of this writing, NASA has confirmed the existence of 5,743 exoplanets consisting of a wide range of sizes, compositions, and have been found in solar systems containing single planets or up to seven planets. The methods used to detect exoplanets also demonstrate diversity, including the transit method, radial velocity method, microlensing method, and the direct imaging method. Each with their own unique ways of not only identifying exoplanets, but also gathering data about their surface compositions, atmospheric compositions, and potential for life. Therefore, how can the BFT contribute to finding life beyond Earth?
Dr. van Belle tells Universe Today, “BFT will primarily be doing follow-up of exoplanets, rather than finding them, but in doing so will contribute to much better characterization of the exoplanets and their hosts. A lot of ‘is there life out there’ is riding on not just the exoplanet but the conditions handed to that exoplanet by its host. Knowing the ‘space weather’ environment will get much better information from BFT observations.”
Along with the potential exoplanet movies and improved science of bright stars, one of the primary driving forces behind BFT is its cost, as the researchers estimate the total cost of the entire project is $28,496,000 for all 16 telescopes at 0.5 meters each. In contrast, the GSU CHARA array cost more than $14.5 million for just six telescopes at 1-meter each, and the construction costs for the VLT/VLTI is estimated in the hundreds of millions of dollars for four 8.2-meter telescopes and four movable 1.8-meter telescopes.
Credit: van Belle & Jorgensen (2024)This recent study provides an in-depth cost breakdown for each aspect of the BFT, including beam collection ($4,720,000), beam transport ($2,744,000), beam combination ($4,140,000), beam delay ($4,000,000), infrastructure ($1,943,000), and labor ($5,250,000). But, given each BFT telescope is each smaller than those used on the GSY CHARA and VLTI, thus meaning their collecting aperture size is smaller, what is the significance of using 0.5-meter collecting aperture size and what is the reason for BFT targeting bright stars?
“The 0.5-m telescopes have a big impact on the affordability of the project,” Dr. van Belle tells Universe Today. “The smaller telescopes are less expensive, both for the telescope tube & the mount. This in turn means the enclosure is smaller & cheaper, too. With half-meter telescopes, simple tip-tilt atmospheric correction is sufficient, rather than more expensive multi-element adaptive optics. And since there’s 16 apertures, every reduction in cost per station has a big domino effect. And yes, the major trade happening here is that the facility can only observe brighter objects – eg. primarily bright stars.”
Just like space telescopes, building ground-based takes years of funding, tests, planning, and construction. This involves getting the necessary funding from multiple parties and organizations and finding an appropriate construction site for the location. Additionally, testing the telescopes prior to installation is essential for them to conduct successful science, in both the short- and long-term.
For example, the GSU CHARA array was founded in 1984, which was followed by years of funding efforts that finally completed in 1998, and the construction of the array was not completed until 2003. For the VLT/VLTI, funding began in 1987, construction began in 1991, and was completed in 1998. Therefore, what are the next steps to make BFT a reality?
“So, the BFT is interesting in how it scales,” Dr. van Belle tells Universe Today. “Right now, we’re doing lab work to verify some of the underlying technology; quite a bit of that tech has already been maturely deployed at places like the Georgia State University CHARA Array, or the European Southern Observatory VLTI facility. Following on that, our next steps will be to test, on sky, a single pair of telescopes. The BFT is daisy-chained from 16 such telescopes, but we can already test its performance with just two. This scalability makes the BFT a much lower-risk telescope than conventional large facilities, where you have to more or less build the whole dang thing before you can test it on sky.”
How will the BFT contribute to optical interferometry in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
The post The Big Fringe Telescope. A 2.2 KILOMETER Telescope on the Cheap. And it Can Make Exoplanet “Movies”. appeared first on Universe Today.
Looking for ground hornbills in Timbavati
We rose early today to meet two researchers on ground hornbills, Kyle-Mark Middleton and Carrie Hickman, to see if we could get a glimpse of the rare bird in nearby Timbavati Private Nature Reserve. Kyle and Carrie, research partners with Rita (whom you’ve already met) and a few others, have been studying ground hornbills for several years.
The work is not easy as these birds are rare, big, nasty, and nest in tree holes or nest boxes provided by the researchers. They breed rarely, and, in this dry winter season, are very scarce. We went out knowing that our chance of seeing the bird or even hearing its call were slim, but it gave us a chance to get back in the bush again. And we did see some cool things.
First, the main players. The study object is the Southern Ground Hornbill, (Bucorvus leadbeateri)l, one of two species of Ground Hornbill in Africa.
Here’s a photo from Wikipedia labeled “A male Southern ground hornbill on the S21 Road west of Lower Sabie, Kruger National Park, South Africa”:
Source: Bernard DUPONT from FRANCE, CC BY-SA 2.0, via Wikimedia Commons
Some information from Wikipedia:
Southern ground hornbills are carnivorous and hunt mostly on the ground. Their food ranges from insects to small vertebrates. Their nests are often found in high tree cavities or other shallow cavities, such as rock holes in cliff faces These birds are a long-lived species, having lifespans in the range of 50–60 years, and up to 70 in captivity. In relation to their long lives, they do not reach sexual maturity until 4–6 years old, and begin breeding around 10 years old.Their sex can be identified by the colour of their throats: the male’s is pure red and the female’s is a deep violet-blue.
And they have an unusual breeding system, involving nonbreeding helpers at the nest and obligate “siblicide,” with two to three eggs being laid, but the parents neglecting all but the largest (and first-hatched) chick. This means that the others always die. (Nature is cruel, isn’t it?). But if the first-born chick dies, they’ll feed another so that one offspring is produced. That is, if there is no predation, yet they have many predators, ranging from leopards to civets. And the birds breed slowly, producing one chick about every three years. No wonder the species is endangered in some places (e.g., South Africa) and threatened in others. This is due largely to habitat loss. More from Wikipedia (bolding is mine):
The southern ground hornbill is an obligate cooperative breeder, with each breeding pair always assisted by at least two other birds. Experiments in captivity have found that birds without six years experience as helpers at the nest are unable to breed successfully if they do become breeders. This suggests that unaided pairs cannot rear young and that the skill gained in helping as a juvenile is essential for rearing young as an adult.
They live as long as parrots!:
In captivity, a maximum lifespan of 70 years is recorded, and it is generally believed that the life expectancy of a bird that survives long enough to fledge is as high as thirty years or more, which is comparable to that of more famously long-lived birds like the wandering albatross.
Ground hornbills are believed to reach maturity at six to seven years, but very few breed at this age. Nests are almost always deep hollows in very old trees, though there exist reports ground hornbills have on occasions nested on rock faces. One to three eggs are laid at the beginning of the wet season, but siblicide ensures that only one nestling is ever fledged. The eggs measure 73 millimetres (2.87 in) by 56 millimetres (2.20 in) and are pure white in colour but very rough in texture.
After a 40 to 45-day incubation period and an 85-day fledging period, the young remain dependent on their parents and helpers for between one and two years depending on climatic conditions, longer than any other bird. This means that ground hornbills can normally breed successfully only every third year. Triennial breeding is rare in birds: probably the only other example is the ornate hawkeagle of Neotropical rainforests.
The researchers below): Kyle and Carrie, dedicated to studying these birds. They raised the money to buy this special hornbill study truck, complete with a long ladder to climb up to the nest holes or nest boxes. (Apologies for my shadow in the picture.) Kyle is South African, and Carrie is from Scotland, but has been enamored of the animals of Africa since she was a girl. She made one trip to the Serengeti and other parts of the continent, met Kyle. Now they’re married and permanent members of Team Hornbill.
We were told beforehand that the chances were slim that we’d see any of the birds, but that was okay, and it turned out that we had a wonderful four or five hours in the park. Kyle climbed up to one artificial nest box to install a camera trap, and also went up up a baobab tree to investigate a genuine cavity where rangers had reported hornbills hanging around.
Getting up early gives you the chance to see one of the loveliest sights in the world: African sunrise in the bush:
And there was wildlife on tap, including a Kori Bustard (Ardeotis kori), the largest flying bird native to Africa. It’s not easy to see these omnivores (mostly carnivores), who are shy and spend most of their time foraging on foot:
A female Greater Kudu (Tragelaphus strepsiceros) showed up:
A small, shy common duiker (Sylvicapra grimmia), bearing tiny, cute horns, peeked at us through the brush. This is a male, for females of this species are hornless:
And a big Nile crocodile lurked in the “dam” (the term for a large water hole), waiting to waylay a thirsty animal:
The geographic area is shown below. Timbavati was created in 1956 by a group of about 50 private landowners concerned about the despoliation of the land by farming and the consequent loss of wildlife. They joined together to create a park designed to restore and conserve the original flora and fauna, and have largely succeeded.
The park, still a private reserve, is right next to Kruger, where we’re going tomorrow, and in 1993 the fences between the two reserves were removed, as they have been for many parks in the area. Without fences the animals can now roam freely and widely, getting a better chance to find food, water, and mates. This is truly one of the world’s most successful conservation efforts despite the persistence of poaching (mainly rhinos and elephants).
Here’s where the park is located; it’s close to where I’m staying in Hoedspruit:
Htonl, CC BY-SA 3.0, via Wikimedia Commons
Location of Mpumalanga province in South Africa
TUBS, CC BY-SA 3.0, via Wikimedia Commons
Driving around, Kyle and Carrie checked an artificial nest box that they’d placed in a tree. Kyle carried the long ladder to the tree, climbed up to the box, and found that a genet had apparently taken residence. That genet will be expelled by a hornbill, as the aggressive birds brook no intrusion of their nests, even by eagles:
Checking inside the nest box:
They decided to put a camera trap next to the next box to monitor it over the coming months. The trap is set to take a photo when it’s activated by motion or infrared light, and takes two pictures a minute so long as there’s something to detect. It will remain functional until the summer breeding season.
Here Carrie puts together the camera, and Kyle climbed back up the tree and installed it:
A plant interlude: One of the unique botanical features of Africa is the Baobab Tree. Curiously, although they can become HUGE, they are regarded as succulents rather than true trees, though I suppose that depends on your definition of “tree”.
There are eight species of baobab in Africa, all in the genus Adansonia, but six are endemic only to Madagascar. The most common one, and one I hear is all over Kruger, is the African baobab, A. digitata. From Wikipedia:
These are long-lived pachycauls; radiocarbon dating has shown some individuals to be over 2,000 years old. They are typically found in dry, hot savannas of sub-Saharan Africa, where they dominate the landscape and reveal the presence of a watercourse from afar. They have traditionally been valued as sources of food, water, health remedies or places of shelter and are a key food source for many animals. They are steeped in legend and superstition. In recent years, many of the largest, oldest trees have died, for unknown reasons.
Here’s the first African baobab I’ve seen; it was exciting. It was also full of vultures. Look at that huge trunk!
The bark was weird:
Kyle and Carrie saw a likely cavity in the tree that, as I said, has reportedly had ground hornbills around it. Kyle, who is tall, tried to climb the ladder to photograph the hole, but he couldn’t reach it. They have a longer ladder on order:
Carrie provided me with some information about the Hornbill work, as well as some cool videos they took. First, the Ground Hornbill Project website is still under construction, but you can find some details about the project, run by the run by the FitzPatrick Institute of African Ornithology at this website.
The project is being run on a shoestring budget and a patchwork of grants and donations, so if you wish to donate to Kyle and Carrie’s work, Wild Wonderful World collects donations for it at this PayPal link. If you’re feeling birdy or conservationish, and want to help a worthy effort to save an endangered bird, you might toss a few bucks their way.
Here are a few videos from the Hornbill Project of what Carries calls “these wonderfully weird birds”. First, their strange vocalizations:
Captions from Carrie: “Interesting interaction between male and female at nest”:
“Ground hornbill destroying one of our cameras”:
“Leopard predation video” Trigger warning: nature red in tooth and claw. The leopard drops the bird at about 1:45 and the despondent parents return to find their baby is missing.
Near the baobab tree above was a lovely tree wisteria (Bolusanthus speciosus) in bloom, being pollinated by bees and other insects I couldn’t identify:
A few feet from the wisteria was the skull of an ex African Buffalo, probably taken down by lions and now singing with the Choir Invisible.
I lifted the skull, and oy, was it heavy! (Photo by Kyle).
Coincidentally, the headquarters of the park has a small but very nice museum with stuffed specimens or skeletons of animals in the park, And here is what was said to be the largest known specimen (in terms of horn-tip-to-horn-tip width) of the same species:
At first I read the label as “Buffalo Bill,” a remnant of my Howdy Doody-watching days. The horn span was, as you see, nearly five feet and three inches across.
However, Wikipedia says this:
In large bulls, the distance between the ends of the horns can reach upwards of one metre (the record being 64.5 inches 164 cm).
Buffalo Bull, above, appears to be about two inches shy of the world record.
In front of the museum is an unlabeled statue of a ranger.
I was told that this is the statue of Anton Mzima, killed in 2022 for preventing poaching:
Anton Mzima once said, “I am not shy to say that I’m a hero. Because I know that the poacher, before he shoots at the rhino, is going to shoot at me first.”
And this is exactly what happened outside his home in Edinburgh Trust near Bushbuckridge, Mpumalanga, on Tuesday. The courageous head of ranger services at Timbavati reserve was gunned down in cold blood. His wife was also shot and is fighting for her life.
Mzimba had worked at Timbavati for 25 years, dedicating his life to the protection of wildlife. At the 2016 Rhino Conservation Awards, he was given the Best Field Ranger award. He also served as technical adviser for the US-based Global Conservation Corps.
Mzimba’s murder left the conservation world stunned, with many friends and colleagues taking to social media to pay tribute and mourn the tremendous loss of this wildlife warrior.
. . .“The year 2008 saw Anton lifted into the leader he was meant to be — Head of Ranger Services for the Timbavati Private Nature Reserve. The impact that this one man has had, not only within the wildlife space, but also touching the lives of and inspiring young children, has been simply enormous,” said the reserve.
Timbavati said Mzimba worked tirelessly in motivating the youth to become rangers, creating a vision of hope for young people to grow up respecting and protecting wildlife as he had.
“Something he shared with everyone he met, was that a field ranger should be seen as a hero, someone to aspire to become. Anton lived his beliefs, never wavered from his convictions and, above all, he remained a brave and honest man.
He was a hero! Here’s a photo of Mzima from Helping Rhinos:
Here’s a trailer of a brand-new movie about Mzima, “Rhino Man”:
Finally, a few odds and ends from Hoedspruit the last few days. Ozy has been scarce, but he’s still around. Yesterday Mama Pig came with her two young boys. We originally thought one of the babies was doomed as it choked when it ate, and was rapidly losing weight. But mirabile dictu, he’s now eating normally and has gained weight nearly equal to that of his twin brother:
A a southern red-billed hornbill (Tockus rufirostris), of which there are plenty around my lodging:
On Friday night we ate at a railroad-themed restaurant, which used to be a station on the north-south line that no longer stops in Hoedspruit, and carries not passengers but freight. The owner has lined the place with old African railway memorabilia, including this poster for the Uganda Railway. Look at all the animals converging on the train, begging to be shot!
And a memory of the bad old days of apartheid: the car for all passengers who weren’t white. You might remember that Mohandas Karamchand Gandhi’s career as an activist, culminating in the Quit India movement that got the British out, began when, as a lawyer in South Africa, he was thrown off a train for being in the “white” car:
On the night of 7 June 1893, a young Indian lawyer, known to the world as ‘Mahatma Gandhi’, was thrown off a train at the Pietermaritzburg Railway Station. He had refused to move from a whites-only compartment. Gandhi later wrote: “I was afraid for my very life. I entered the dark waiting-room. There was a white man in the room. I was afraid of him. What was my duty? I asked myself. Should I go back to India, or should I go forward with God as my helper, and face whatever was in store for me? I decided to stay and suffer. My active non-violence began from that date”. It was a Rosa Parks moment, but occurred many years earlier:
More later, probably several days after I get back from Kruger. I’ll be taking photos all the while, though.
What Makes a Supercluster?
By eye, it’s impossible to pick out the exact boundaries of the superclusters, which are among the largest structures in the universe. But that’s because they are not defined by their edges, but by the common motion of their components.
The Milky Way galaxy was long thought to be a member of the Virgo supercluster, a complex, twisting branch containing over 100 individual galaxy groups and clusters stretching for more than a hundred million light-years. Astronomers arrived at that definition through some of the earliest galaxy surveys that attempted to map the nearby portions of the universe.
Those early surveys were not entirely sophisticated. Astronomers could spot the galaxies scattered around, and also dense clumps of galaxies known as clusters. Ever since the 1950’s astronomers debated if there were higher-order structures in the pattern of galaxies, wondering if “super-galaxies” (or superclusters) existed.
Once astronomers began to map deep into the universe, however, the cosmic web could not be ignored. While some galaxies found their homes in the clusters, most inhabited long, thin filaments and broad walls. This cosmic web was defined by the voids, the vast regions of almost-nothing that dominate the volume of the universe.
The largest portions of the cosmic web are the superclusters. But unlike the clusters, they are not gravitationally bound. That means that the member galaxies in a supercluster have not yet finished their building project. The superclusters are still in the process of forming. This fact makes it difficult to pick out exactly what a supercluster is.
Recently astronomers have turned to dynamical definitions of a supercluster. This means that they don’t just consider the position in space of a particular galaxy, but also its movement. Since superclusters are in the process of continual construction, this method looks at what galaxies are trying to build.
This method allows astronomers to distinguish one supercluster from another, and that’s how we’ve recognized that the Virgo supercluster is just one individual branch of a much larger structure known as Laniakea, which contains an astounding 100,000 galaxies. And that is our home in the universe.
The post What Makes a Supercluster? appeared first on Universe Today.
Internet-based hiatus in posting
Tomorrow at 5:30 a.m. we’re heading off to Kruger until the 30th. I’ve been told that internet in the park and in the huts is either bad or unavailable, so I’m writing this to let you know that posting may be nearly nonexistent until I get.back to Capetown on the 31st. Perhaps Matthew might start a discussion, but I haven’t told him to.
Later today there should be another photo post on our search for ground hornbills in Timbavati Nature Reserve with two researchers who study these bizarre birds. We didn’t see any, nor did we expect to, but we saw plenty else. Stay tuned.
As always, I do my besst.
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