Spinosaurus is the biggest carnivorous dinosaur ever discovered—even bigger than T. rex—but the way it hunted has been a subject of debate for decades. It’s hard to guess the behavior of an animal that we only know from fossils; based on its skeleton, some scientists have proposed that Spinosaurus could swim, but others believe that it just waded in the water like a heron. Since looking at the anatomy of spinosaurid dinosaurs wasn’t enough to solve the mystery, a group of paleontologists are publishing a new study in Nature that takes a different approach: examining the density of their bones. By analyzing the density of spinosaurid bones and comparing them to other animals like penguins, hippos, and alligators, the team found that Spinosaurus and its close relative Baryonyx had dense bones that likely would have allowed them to submerge themselves underwater to hunt. Meanwhile, another related dinosaur called Suchomimus had lighter bones that would have made swimming more difficult, so it likely waded instead or spent more time on land like other dinosaurs.
“The fossil record is tricky—among spinosaurids, there are only a handful of partial skeletons, and we don’t have any complete skeletons for these dinosaurs,” says Matteo Fabbri, a postdoctoral researcher at the Field Museum and the lead author of the study in Nature. “Other studies have focused on interpretation of anatomy, but clearly if there are such opposite interpretations regarding the same bones, this is already a clear signal that maybe those are not the best proxies for us to infer the ecology of extinct animals.”
All life initially came from the water, and most groups of terrestrial vertebrates contain members that have returned to it—for instance, while most mammals are land-dwellers, we’ve got whales and seals that live in the ocean, and other mammals like otters, tapirs, and hippos that are semi-aquatic. Birds have penguins and cormorants; reptiles have alligators, crocodiles, marine iguanas, and sea snakes. For a long time, non-avian dinosaurs (the dinos that didn’t branch off into birds) were the only group that didn’t have any water-dwellers. That changed in 2014, when a new Spinosaurus skeleton was described by Nizar Ibrahim at the University of Portsmouth.
Scientists already knew that spinosaurids spent some time by water—their long, croc-like jaws and cone-shaped teeth are similar to other aquatic predators’, and some fossils had been found with bellies full of fish. But the new Spinosaurus specimen described in 2014 had retracted nostrils, short hind legs, paddle-like feet, and a fin-like tail: all signs that pointed to an aquatic lifestyle. But researchers have continued to debate whether spinosaurids actually swam for their food or if they just stood in the shallows and dipped their heads in to snap up prey. This continued back-and-forth led Fabbri and his colleagues to try to find another way to solve the problem.
“The idea for our study was, okay, clearly we can interpret the fossil data in different ways. But what about the general physical laws?” says Fabbri. “There are certain laws that are applicable to any organism on this planet. One of these laws regards density and the capability of submerging into water.”
Across the animal kingdom, bone density is a tell in terms of whether that animal is able to sink beneath the surface and swim. “Previous studies have shown that mammals adapted to water have dense, compact bone in their postcranial skeletons,” says Fabbri. Dense bone works as buoyancy control and allows the animal to submerge itself.
“We thought, okay, maybe this is the proxy we can use to determine if spinosaurids were actually aquatic,” says Fabbri.
Fabbri and his colleagues, including co-corresponding authors Guillermo Navalón at Cambridge University and Roger Benson at Oxford University, put together a dataset of femur and rib bone cross-sections from 250 species of extinct and living animals, both land-dwellers and water-dwellers. The researchers compared these cross-sections to cross-sections of bone from Spinosaurus and its relatives Baryonyx and Suchomimus. “We had to divide this study into successive steps,” says Fabbri. “The first one was to understand if there is actually a universal correlation between bone density and ecology. And the second one was to infer ecological adaptations in extinct taxa” Essentially, the team had to show a proof of concept among animals that are still alive that we know for sure are aquatic or not, and then applied them to extinct animals that we can’t observe.
When selecting animals to include in the study, the researchers cast a wide net. “We were looking for extreme diversity,” says Fabbri. “We included seals, whales, elephants, mice, hummingbirds. We have dinosaurs of different sizes, extinct marine reptiles like mosasaurs and plesiosaurs. We have animals that weigh several tons, and animals that are just a few grams. The spread is very big.”
This menagerie of animals revealed a clear link between bone density and aquatic foraging behavior: animals that submerge themselves underwater to find food have bones that are almost completely solid throughout, whereas cross-sections of land-dwellers’ bones look more like donuts, with hollow centers. “There is a very strong correlation, and the best explanatory model that we found was in the correlation between bone density and sub-aqueous foraging. This means that all the animals that have the behavior where they are fully submerged have these dense bones, and that was the great news,” says Fabbri.
When the researchers applied spinosaurid dinosaur bones to this paradigm, they found that Spinosaurus and Baryonyx both had the sort of dense bone associated with full submersion. Meanwhile, the closely related Suchomimus had hollower bones. It still lived by water and ate fish, as evidenced by its crocodile-mimic snout and conical teeth, but based on its bone density, it wasn’t actually swimming.
Other dinosaurs, like the giant long-necked sauropods also had dense bones, but the researchers don’t think that meant they were swimming. “Very heavy animals like elephants and rhinos, and like the sauropod dinosaurs, have very dense limb bones, because there’s so much stress on the limbs,” explains Fabbri. “That being said, the other bones are pretty lightweight. That’s why it was important for us to look at a variety of bones from each of the animals in the study.” And while there are limitations to this kind of analysis, Fabbri is excited by the potential for this study to tell us about how dinosaurs lived.
“One of the big surprises from this study was how rare underwater foraging was for dinosaurs, and that even among spinosaurids, their behavior was much more diverse that we’d thought,” says Fabbri.
Jingmai O’Connor, a curator at the Field Museum and co-author of this study, says that collaborative studies like this one that draw from hundreds of specimens, are “the future of paleontology. They’re very time-consuming to do, but they let scientists shed light onto big patterns, rather than making qualitative observations based on one fossil. It’s really awesome that Matteo was able to pull this together, and it requires a lot of patience.”
Fabbri also notes that the study shows how much information can be gleaned from incomplete specimens. “The good news with this study is that now we can move on from the paradigm where you need to know as much as you can about the anatomy of a dinosaur to know about its ecology, because we show that there are other reliable proxies that you can use. If you have a new species of dinosaur and you just have only a few bones of it, you can create a dataset to calculate bone density, and at least you can infer if it was aquatic or not.”
Matteo Fabbri, Subaqueous foraging among carnivorous dinosaurs, Nature (2022). DOI: 10.1038/s41586-022-04528-0. www.nature.com/articles/s41586-022-04528-0
Dense bones allowed Spinosaurus to hunt underwater, study shows (2022, March 23)
retrieved 23 March 2022
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
You’ve Seen the New Image of the Milky Way’s Black Hole – Now Hear It! – SciTechDaily
This is a sonification — translation into sound — of the latest image from the Event Horizon Telescope (EHT) of the supermassive black hole at the center of the Milky Way called Sagittarius A* (Sgr A*). Using a radar-like scan, the sonification begins at the 12 o’clock position and sweeps clockwise. Changes in the volume represent the differences in brightness the EHT observed around the event horizon of Sgr A*. The material that is closer to the <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="
” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>black hole and hence moving faster corresponds to higher frequencies of sound. This sonification was processed in a special way to allow a listener to hear the data in 3D stereo sound, in which the sounds seem to start directly ahead and then move clockwise to one ear and then the other as the sweep is made.
About the Sound:
- This is a radar-like scan, starting from 12 o’clock and moving clockwise.
- The brightness controls the volume and the radial position controls the frequencies that are present.
- The emission from material closer to the black hole (which orbits faster) is mapped to higher frequencies.
- The sound is rendered in binaural audio. When listened to with headphones, the sound will appear to start directly in front of you and then move clockwise all the way around your head.
- Listen for the three bright regions at about 1, 5, and 9 o’clock, as well as the very low tones indicating fainter light from outside the main ring.
Sonification Credit: <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="
” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida);
Image Credit: Radio: EHT Collaboration; X-ray (NASA/CXC/SAO); Infrared (NASA/HST/STScI)
When Is The Next Total Lunar Eclipse ‘Blood Moon?’ The Coming Once-In-430 Years ‘Twin’ Totality Will Be The Longest Until 2029 – Forbes
If you’re reading this having just seen the spectacular sight of the “Blood Moon” (or perhaps you didn’t because of cloud) it’s likely that there’s only one question on your mind: when’s the next one?
The next total lunar eclipse is on Monday, November 7 and into Tuesday, November 8, 2022. That’s in just 145 days! It will be best seen from west coast of North America, with Australia and southeast Asia also in a good position.
Like the events of May 15-16 it will also features an 84-minute totality (it’s actually four seconds longer). That’s highly unusual. According to Timeanddate.com, it’s the most balanced pair of lunar eclipses in 430 years.
November’s eclipse will be just as long as what North America just experienced, with lunar totality seeing the full “Frosty” or “Beaver” Moon turn a spectacular reddish color for 84 minutes.
That kind of duration of totality won’t be topped until a 102 minute totality on June 26, 2029.
A total lunar eclipse can be seen from any given location every 2.5 years, on average, and that plays out in the 2020s. The following total lunar eclipse is on March 13-14, 2025.
North America will once again get a good view, though it comes at a time of year when cloud will likely be a big problem.
It will almost be part of a “tetrad,” which is when four consecutive eclipse seasons—which are about six months apart—each contain a total lunar eclipse. However, the final event is a bit of a celestial letdown:
- March 14, 2025: Total lunar eclipse
- September 7, 2025: Total lunar eclipse
- March 3, 2026: Total lunar eclipse
- August 28, 2026: Partial lunar eclipse
However, with 93% of the Moon covered by the Earth’s shadow at the peak even that will be a sight to behold.
What is an ‘eclipse season?’
Every 173 days (six months), for between 31 and 37 days, the Moon is lined-up perfectly to intersect the ecliptic—the apparent path of the Sun through our daytime sky and the plane of Earth’s orbit around the Sun.
The result, of course, is a short season during which two—and occasionally three—solar and lunar eclipses can occur.
Disclaimer: I am the editor of WhenIsTheNextEclipse.com
Wishing you clear skies and wide eyes.
Starlink Group 4-13 | Falcon 9 Block 5 – Everyday Astronaut
Featured image credit: SpaceX
Lift Off Time
|May 13, 2022 – 22:07 UTC | 15:07 PDT|
|Starlink Group 4-13; the fifteenth launch to Starlink Shell 4|
|Falcon 9 Block 5, B1063-5; 108.20 day turnaround|
|Space Launch Complex 4 East (SLC-4E), Vandenberg Space Force Base, California, USA|
|~16,250 kg (~35,800 lb) (53 x 307 kg, plus dispenser)|
Where did the satellites go?
|Starlink Shell 4; 540 km circular low-Earth orbit (LEO); initial orbit: 315 x 305 km at 53.22°|
Did they attempt to recover the first stage?
Where did the first stage land?
|B1063 successfully landed 642 km downrange on Of Course I Still Love You
Tug: Debra C; Support: GO Quest
Did they attempt to recover the fairings?
|The fairing halves were recovered from the water ~654 km downrange by NRC Quest|
Were these fairings new?
|No, both fairing halves were flight proven|
This was the:
|– 153rd Falcon 9 launch
– 93rd Falcon 9 flight with a flight proven booster
– 97th re-flight of a booster
– 18th re-flight of a booster in 2022
– 119th booster landing
– 45th consecutive landing (a record)
– 19th launch for SpaceX in 2022
– 23rd SpaceX launch from SLC-4E
– 53rd orbital launch attempt of 2022
Where to watch
How Did It Go?
SpaceX’s Starlink Group 4-13 mission successfully launched 53 Starlink satellites atop a Falcon 9 rocket. The Falcon 9 lifted off from Space Launch Complex 4 East (SLC-4E), at the Vandenberg Space Force Base, in California, United States. Starlink Group 4-13 marked the 44th operational Starlink mission, boosting the total number of Starlink satellites launched to 2,547, of which 2,300 are in orbit around the Earth. Starlink Group 4-13 marked the 15th launch to the fourth Starlink shell; roughly 30 launches will be required to fill this shell.
Starlink is SpaceX’s internet communication satellite constellation. The low-Earth orbit constellation will deliver fast, low-latency internet service to locations where ground-based internet is unreliable, unavailable, or expensive. The first phase of the constellation consists of five orbital shells.
Starlink is currently available in certain regions, allowing anyone in approved regions to order or preorder. After 28 launches SpaceX achieved near-global coverage, but the constellation will not be complete until ~42,000 satellites are in orbit. Once Starlink is complete, the venture is expected to profit $30-50 billion annually. This profit will largely finance SpaceX’s ambitious Starship program, as well as Mars Base Alpha.
Each Starlink V1.5 satellite has a compact design and a mass of 307 kg. SpaceX developed a flat-panel design, allowing them to fit as many satellites as possible into the Falcon 9’s 5.2 meter wide payload fairing. Due to this flat design, SpaceX is able to fit up to 60 Starlink satellites and the payload dispenser into the second stage, while still being able to recover the first stage. This is near the recoverable payload capacity of the Falcon 9 to LEO, around 16 tonnes.
As small as each Starlink satellite is, each one is packed with high-tech communication and cost-saving technology. Each Starlink satellite is equipped with four phased array antennas, for high bandwidth and low-latency communication, and two parabolic antennas. The satellites also include a star tracker, which provides the satellite with attitude data, ensuring precision in broadband communication.
Each Starlink V1.5 satellite is also equipped with an inter-satellite laser communication system. This allows each satellite to communicate directly with other satellites, not having to go through ground stations. This reduces the number of ground stations needed, allowing coverage of the entire Earth’s surface, including the poles.
The Starlink satellites are also equipped with an autonomous collision avoidance system, which utilizes the US Department of Defense (DOD) debris tracking database to autonomously avoid collisions with other spacecraft and space junk.
To decrease costs, each satellite has a single solar panel, which simplifies the manufacturing process. To further cut costs, Starlink’s propulsion system, an ion thruster, uses krypton as fuel, instead of xenon. While the specific impulse (ISP) of krypton is significantly lower than xenon’s, it is far cheaper, which further decreases the satellite’s manufacturing cost.
Each Starlink satellite is equipped with the first Hall-effect krypton-powered ion thruster. This thruster is used for both ensuring the correct orbital position, as well as for orbit raising and orbit lowering. At the end of the satellite’s life, this thruster is used to deorbit the satellite.
A satellite constellation is a group of satellites that work in conjunction for a common purpose. Currently, SpaceX plans to form a network of 11,716 satellites; however, in 2019 SpaceX filed an application with the Federal Communication Commission (FCC) for permission to launch and operate an additional 30,000 satellites as part of phase 2 of Starlink. To put this number of satellites into perspective, this is roughly 20 times more satellites than were launched before 2019.
Of the initial ~12,000 satellites, ~4,400 would operate on the Ku and Ka bands, with the other ~7,600 operating on the V-Band.
Due to the vast number of Starlink satellites, many astronomers are concerned about their effect on the night sky. However, SpaceX is working with the astronomy community and implementing changes to the satellites to make them harder to see from the ground and less obtrusive to the night sky. SpaceX has changed how the satellites raise their orbits and, starting on Starlink V1.0 L9, added a sunshade to reduce light reflectivity. These changes have already significantly decreased the effect of Starlink on the night sky.
|Inclination (°)||Orbital Altitude (km)||Number of Satellites|
The first orbital shell of Starlink satellites consists of 1,584 satellites in a 53.0° 550 km low-Earth orbit. Shell 1 consists of 72 orbital planes, with 22 satellites in each plane. This shell is currently near complete, with occasional satellites being replaced. The first shell provides coverage between roughly 52° and -52° latitude (~80% of the Earth’s surface), and will not feature laser links until replacement satellites launch after 2021.
Starlink’s second shell will host 720 satellites in a 70° 570 km orbit. These satellites will significantly increase the coverage area, which will make the Starlink constellation cover around 94% of the globe. SpaceX will put 20 satellites in each of the 36 planes in the third shell. This shell is currently being filled, along with Shell 4.
Shell 3 will consist of 348 satellites in a 97.6° 560 km orbit. SpaceX deployed 10 laser link test satellites into this orbit on their Transporter-1 mission to test satellites in a polar orbit. SpaceX launched an additional three satellites to this shell on the Transporter-2 mission. On April 6, 2021, Gwynne Shotwell said that SpaceX will conduct regular polar Starlink launches in the summer, but this shell is now the lowest priority, and is expected to be the last filled. All satellites that will be deployed into this orbit will have inter-satellite laser link communication. Shell 4 will have six orbital planes with 58 satellites in each plane.
The fourth shell will consist of 1,584 satellites in a 540 km 53.2° LEO. This updated orbital configuration will slightly increase coverage area and will drastically increase the bandwidth of the constellation. This shell will also consist of 72 orbital planes with 22 satellites in each plane. This shell is currently being filled alongside Shell 2.
The final shell of Phase 1 of Starlink will host 172 satellites in another 97.6° 560 km low-Earth polar orbit. Shell 5 will also consist purely of satellites with laser communication links; however, unlike Shell 3, it will consist of four orbital planes with 43 satellites in each plane.
The sixth orbital shell of Starlink satellites is permitted to consist of 2,493 satellites in a 42° 335.9 km LEO. This large number of satellites will decrease latency and increase bandwidth for lower latitudes.
The seventh Starlink shell permits SpaceX to deploy 2,478 satellites into a 48° 340.8 km low-Earth orbit. These satellites will further decrease latency and increase bandwidth for lower latitudes.
The final shell of Starlink Phase 2 allows SpaceX to deploy 2,547 satellites in a 53° 345.6 km orbit.
SpaceX has until March of 2024 to complete half of phase 1 and must fully complete Phase 1 by March of 2027. Phase 2 must be half complete by November of 2024, and be finished by November of 2027. Failure to do so could result in SpaceX losing its dedicated frequency band.
What Is Falcon 9 Block 5?
The Falcon 9 Block 5 is SpaceX’s partially reusable two-stage medium-lift launch vehicle. The vehicle consists of a reusable first stage, an expendable second stage, and, when in payload configuration, a pair of reusable fairing halves.
The Falcon 9 first stage contains 9 Merlin 1D+ sea level engines. Each engine uses an open gas generator cycle and runs on RP-1 and liquid oxygen (LOx). Each engine produces 845 kN of thrust at sea level, with a specific impulse (ISP) of 285 seconds, and 934 kN in a vacuum with an ISP of 313 seconds. Due to the powerful nature of the engine, and the large amount of them, the Falcon 9 first stage is able to lose an engine right off the pad, or up to two later in flight, and be able to successfully place the payload into orbit.
The Merlin engines are ignited by triethylaluminum and triethylborane (TEA-TEB), which instantaneously burst into flames when mixed in the presence of oxygen. During static fire and launch the TEA-TEB is provided by the ground service equipment. However, as the Falcon 9 first stage is able to propulsively land, three of the Merlin engines (E1, E5, and E9) contain TEA-TEB canisters to relight for the boost back, reentry, and landing burns.
The Falcon 9 second stage is the only expendable part of the Falcon 9. It contains a singular MVacD engine that produces 992 kN of thrust and an ISP of 348 seconds. The second stage is capable of doing several burns, allowing the Falcon 9 to put payloads in several different orbits.
For missions with many burns and/or long coasts between burns, the second stage is able to be equipped with a mission extension package. When the second stage has this package it has a grey strip, which helps keep the RP-1 warm, an increased number of composite-overwrapped pressure vessels (COPVs) for pressurization control, and additional TEA-TEB.
Falcon 9 Booster
The booster that supported Starlink Group 4-13 is B1063. As the booster had supported 4 previous flights, its designation for Starlink Group 4-13 is B1063-5. This changed to B1063-6 upon successful landing.
|B1063’s missions||Launch Date (UTC)||Turnaround Time (Days)|
|Sentinel-6||November 21, 2020 17:17||N/A|
|Starlink V1.0 L28||May 26, 2021 18:59||186.07|
|DART||November 24, 2021 06:21||181.47|
|Starlink Group 4-11||February 25, 2022 17:12||62.45|
|Starlink Group 4-13||May 13, 2022 22:07||108.20|
Following stage separation, the Falcon 9 conducted two burns. These burns softly touched down the booster on SpaceX’s autonomous spaceport drone ship Of Course I Still Love You.
Falcon 9 Fairings
The Falcon 9’s fairing consists of two dissimilar reusable halves. The first half (the half that faces away from the transport erector) is called the active half, and houses the pneumatics for the separation system. The other fairing half is called the passive half. As the name implies, this half plays a purely passive role in the fairing separation process, as it relies on the pneumatics from the active half.
Both fairing halves are equipped with cold gas thrusters and a parafoil which are used to softly touch down the fairing half in the ocean. SpaceX used to attempt to catch the fairing halves, however, at the end of 2020 this program was canceled due to safety risks and a low success rate. On Starlink Group 4-13, SpaceX recovered the fairing halves from the water with their recovery vessel NRC Quest.
In 2021, SpaceX started flying a new version of the Falcon 9 fairing. The new “upgraded” version has vents only at the top of each fairing half, by the gap between the halves, whereas the old version had vents placed spread equidistantly around the base of the fairing. Moving the vents decreases the chance of water getting into the fairing, making the chance of a successful scoop significantly higher.
All times are approximate
|00:38:00||SpaceX Launch Director verifies go for propellant load|
|00:35:00||RP-1 (rocket grade kerosene) loading underway|
|00:35:00||1st stage LOX (liquid oxygen) loading underway|
|00:16:00||2nd stage LOX loading underway|
|00:07:00||Falcon 9 begins engine chill prior to launch|
|00:01:00||Command flight computer to begin final prelaunch checks|
|00:01:00||Propellant tank pressurization to flight pressure begins|
|00:00:45||SpaceX Launch Director verifies go for launch|
|00:00:03||Engine controller commands engine ignition sequence to start|
|00:00:00||Falcon 9 liftoff|
Starlink Group 4-13 Launch, Landing, and Deployment
All times are approximate
|00:01:12||Max Q (moment of peak mechanical stress on the rocket)|
|00:02:30||1st stage main engine cutoff (MECO)|
|00:02:34||1st and 2nd stages separate|
|00:02:40||2nd stage engine starts (SES-1)|
|00:06:25||1st stage entry burn start|
|00:06:44||1st stage entry burn complete|
|00:08:10||1st stage landing burn start|
|00:08:33||1st stage landing|
|00:08:46||2nd stage engine cutoff (SECO-1)|
|00:53:40||2nd stage engine starts (SES-2)|
|00:53:41||2nd stage engine cutoff (SECO-2)|
|01:02:42||Starlink satellites deploy|
gas prices reach new high | CTV News – CTV News Toronto
Leafs-Lightning Was Always Going To Leave Someone Haunted – Defector
Bird flu continues to spread among domestic, wild animals throughout North America – Just The News
Silver investment demand jumped 12% in 2019
Europe kicks off vaccination programs | All media content | DW | 27.12.2020 – Deutsche Welle
Global Media Markets, 2015-2020, 2020-2025F, 2030F – TV and Radio Broadcasting, Film and Music, Information Services, Web Content, Search Portals And Social Media, Print Media, & Cable – GlobeNewswire
Health12 hours ago
Eating Disorder Foundation Call Recent CIHI Statistics “Alarming” – VOCM
Health11 hours ago
BC bird flu: Vancouver Island farmers on alert | CTV News – CTV News VI
Real eState2 hours ago
This is what $1-million will get you in real estate markets across Ontario – CTV News Toronto
Art10 hours ago
Judge for yourself: Man uses art to escape 'frenetic' period – BarrieToday
Art10 hours ago
Kirkland Lake museum asks for art donations to help fundraiser – CBC.ca
Health6 hours ago
Mental Health Issues Demand Resolution
Sports2 hours ago
2022 Stanley Cup Playoffs Game 7: Rangers host Penguins and Flames take on Stars on Sunday – CBS Sports
Media2 hours ago
After Buffalo Massacre, Gov. Kathy Hochul Calls for Social Media Companies to Crack Down on Hate Speech – Vanity Fair