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New satellite that will monitor Earth's changing oceans ready to launch – CBC.ca

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A satellite jointly developed by Europe and the United States being launched this weekend will greatly help scientists keep track of the rise in global sea levels, one of the most daunting effects of climate change, a senior official at the European Space Agency said Friday.

The new satellite, called Sentinel-6 Michael Freilich, contains cutting-edge instruments able to capture sea level height with unprecedented accuracy, adding to space-based measurements going back almost 30 years.

“This is an extremely important parameter for climate monitoring,” said Josef Aschbacher, the agency’s director of Earth observation.

Billions of people living in coastal areas around the planet are at risk in the coming decades as melting polar ice and ocean expansion caused by warming water drives sea levels up.

“We know that sea level is rising,” said Aschbacher.

He said the speed of the rising has increased since the 1990s, at first by about three millimetres per year but by almost five millimetres in the past couple of years.

Sentinel-6 Michael Freilich team members from the European Space Agency examine the spacecraft in the processing room at the Vandenberg Air Force Base in California. (ESA/Bill Simpson)

While sea level measurements are also taken at ground level, in harbours and other coastal areas, they don’t provide the same precise uniform standard and breadth as data collected by a single satellite sweeping the entire globe every ten days, said Aschbacher.

“If you measure it at sea level, you have one measurement device in Amsterdam and you have a different one in Bangkok and yet another one in Miami,” Aschbacher told The Associated Press by video from ESA offices in Frascati, Italy. “But with a satellite, you can compare these measurements globally because it’s the same instrument that flies over all these areas.”

Powerful tools

Its most powerful weapon is the Poseidon-4 radar altimeter, named after the trident-wielding Greek god of the sea. The instrument measures how long it takes for radar signals to bounce off the sea surface and back to the satellite.

The new satellite will also collect measurements at higher resolution than its predecessors, allowing researchers to peer more closely at small ocean features, especially along the coastlines.

Other instruments on board will measure how radio signals pass through the atmosphere, providing data on atmospheric temperature and humidity that can help improve global weather forecasts.

The satellite is due to be carried into orbit Saturday from Vandenberg Air Force Base in California aboard a SpaceX Falcon 9 rocket.

Inside SpaceX’s Payload Processing Facility at Vandenberg Air Force Base in California, the U.S.-European Sentinel-6 Michael Freilich ocean-monitoring satellite is seen being encapsulated in the SpaceX Falcon 9 payload fairing on Nov. 3, 2020. (NASA/Randy Beaudoin)

It is named after the late director of NASA’s Earth Science Division, Michael Freilich, an oceanographer who was instrumental in getting the U.S. space agency to join the mission.

“We owe him a lot and he more than deserves to have this satellite named after him,” said Aschbacher. “I’m very sorry personally that he cannot push the button tomorrow.”

Europe and the United States are sharing the 900-million-euro ($1.1-billion US) cost of the 10-year mission, which includes the launch of an identical twin called Sentinel-6B in 2025.

It’s the first time that another space agency has been involved in ESA’s flagship Copernicus mission, which already has seven satellites in orbit measuring the seas, atmosphere and land.

Aschbacher said he hopes NASA and ESA will hook up on future missions, too.

“NASA is our strongest partner internationally,” he said. “We are discussing right now other options of co-operation based on the model of Sentinel 6-Michael Freilich.”

The two space agencies recently agreed to co-operate on a planned NASA outpost around the moon.

But Aschbacher said missions to Earth’s neighbour, and others looking to Mars and beyond, shouldn’t divert attention from the need to keep an eye on our own planet.

“We all know that [Earth] is undergoing enormous changes, extremely fast changes and changes we never had before on this planet with a speed and intensity caused, obviously, by humans,” he said. “And we need to understand how this planet functions for our own survival, for our own future.”

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T. rex got huge via major teenage growth spurt – CBC.ca

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Large meat-eating dinosaurs attained their great size through very different growth strategies, with some taking a slow and steady path and others experiencing an adolescent growth spurt, according to scientists who analyzed slices of fossilized bones.

The researchers examined the annual growth rings — akin to those in tree trunks — in bones from 11 species of theropods, a broad group spanning all the big carnivorous dinosaurs including Tyrannosaurus rex and even birds. The study provides insight into the lives of some of the most fearsome predators ever to walk the Earth.

The team looked at samples from museums in the United States, Canada, China and Argentina and even received clearance to cut into bones from one of the world’s most famous T. rex fossils, known as Sue and housed at the Field Museum in Chicago, using a diamond-tipped saw and drill.

Sue’s leg bones — a huge femur and fibula — helped illustrate that T. rex and its relatives — known as tyrannosaurs — experienced a period of extreme growth during adolescence and reached full adult size by around age 20. Sue, measuring about 13 metres, lived around 33 years.

Sue inhabited South Dakota about a million years before dinosaurs and many other species were wiped out by an asteroid impact 66 million years ago.

Other groups of large theropods tended to have more steady rates of growth over a longer period of time. That growth strategy was detected in lineages that arose worldwide earlier in the dinosaur era and later were concentrated in the southern continents.

Examples included Allosaurus and Acrocanthosaurus from North America, Cryolophosaurus from Antarctica and a recently discovered as-yet-unnamed species from Argentina that rivaled T. rex in size. The Argentine dinosaur, from a group called carcharodontosaurs, did not reach its full adult size until its 40s and lived to about age 50.

Big theropods share the same general body design, walking on two legs and boasting large skulls, strong jaws and menacing teeth.

“Prior to our study, it was known that T. rex grew very quickly, but it was not clear if all theropod dinosaurs reached gigantic size in the same way, or if there were multiple ways it was done,” said paleontologist and study lead author Tom Cullen of the North Carolina Museum of Natural Sciences and North Carolina State University, also affiliated with the Field Museum.

The research was published this week in the journal Proceedings of the Royal Society B.

“Theropod dinosaurs represent the largest bipedal animals to have ever lived and were also the dominant predators in terrestrial ecosystems for over 150 million years — more than twice as long as mammals have been dominant,” added University of Minnesota paleontologist and study co-author Peter Makovicky

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Slow and steady or a big spurt? How to grow a ferocious dinosaur – Cape Breton Post

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By Will Dunham

WASHINGTON (Reuters) – Large meat-eating dinosaurs attained their great size through very different growth strategies, with some taking a slow and steady path and others experiencing an adolescent growth spurt, according to scientists who analyzed slices of fossilized bones.

The researchers examined the annual growth rings – akin to those in tree trunks – in bones from 11 species of theropods, a broad group spanning all the big carnivorous dinosaurs including Tyrannosaurus rex and even birds. The study provides insight into the lives of some of the most fearsome predators ever to walk the Earth.

The team looked at samples from museums in the United States, Canada, China and Argentina and even received clearance to cut into bones from one of the world’s most famous T. rex fossils, known as Sue and housed at the Field Museum in Chicago, using a diamond-tipped saw and drill.

Sue’s leg bones – a huge femur and fibula – helped illustrate that T. rex and its relatives – known as tyrannosaurs – experienced a period of extreme growth during adolescence and reached full adult size by around age 20. Sue, measuring about 42 feet (13 metres), lived around 33 years.

Sue inhabited South Dakota about a million years before dinosaurs and many other species were wiped out by an asteroid impact 66 million years ago.

Other groups of large theropods tended to have more steady rates of growth over a longer period of time. That growth strategy was detected in lineages that arose worldwide earlier in the dinosaur era and later were concentrated in the southern continents.

Examples included Allosaurus and Acrocanthosaurus from North America, Cryolophosaurus from Antarctica and a recently discovered as-yet-unnamed species from Argentina that rivaled T. rex in size. The Argentine dinosaur, from a group called carcharodontosaurs, did not reach its full adult size until its 40s and lived to about age 50.

Big theropods share the same general body design, walking on two legs and boasting large skulls, strong jaws and menacing

teeth.

“Prior to our study, it was known that T. rex grew very quickly, but it was not clear if all theropod dinosaurs reached gigantic size in the same way, or if there were multiple ways it was done,” said paleontologist and study lead author Tom Cullen of the North Carolina Museum of Natural Sciences and North Carolina State University, also affiliated with the Field Museum.

The research was published this week in the journal Proceedings of the Royal Society B.

“Theropod dinosaurs represent the largest bipedal animals to have ever lived and were also the dominant predators in terrestrial ecosystems for over 150 million years – more than twice as long as mammals have been dominant,” added University of Minnesota paleontologist and study co-author Peter Makovicky.

(Reporting by Will Dunham; Editing by Peter Cooney)

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Neutrinos Yield First Experimental Evidence of the CNO Energy-Production Mechanism of the Universe – SciTechDaily

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View into the interior of the Borexino detector. Credit: Borexino Collaboration

Neutrinos Yield First Experimental Evidence of Catalyzed Fusion Dominant in Many Stars

An international team of about 100 scientists of the Borexino Collaboration, including particle physicist Andrea Pocar at the University of Massachusetts Amherst, report in Nature this week detection of neutrinos from the sun, directly revealing for the first time that the carbon-nitrogen-oxygen (CNO) fusion-cycle is at work in our sun.

The CNO cycle is the dominant energy source powering stars heavier than the sun, but it had so far never been directly detected in any star, Pocar explains.

For much of their life, stars get energy by fusing hydrogen into helium, he adds. In stars like our sun or lighter, this mostly happens through the ‘proton-proton’ chains. However, many stars are heavier and hotter than our sun, and include elements heavier than helium in their composition, a quality known as metallicity. The prediction since the 1930’s is that the CNO-cycle will be dominant in heavy stars.

Neutrinos emitted as part of these processes provide a spectral signature allowing scientists to distinguish those from the ‘proton-proton chain’ from those from the ‘CNO-cycle.’ Pocar points out, “Confirmation of CNO burning in our sun, where it operates at only one percent, reinforces our confidence that we understand how stars work.”

Borexino Detector Under Apennine Mountains

The Borexino detector lies deep under the Apennine Mountains in central Italy at the INFN’s Laboratori Nazionali del Gran Sasso. It detects neutrinos as flashes of light produced when neutrinos collide with electrons in 300-tons of ultra-pure organic scintillator. Credit: Borexino Collaboration

Beyond this, CNO neutrinos can help resolve an important open question in stellar physics, he adds. That is, how the sun’s central metallicity, as can only be determined by the CNO neutrino rate from the core, is related to metallicity elsewhere in a star. Traditional models have run into a difficulty – surface metallicity measures by spectroscopy do not agree with the sub-surface metallicity measurements inferred from a different method, helioseismology observations. 

Pocar says neutrinos are really the only direct probe science has for the core of stars, including the sun, but they are exceedingly difficult to measure. As many as 420 billion of them hit every square inch of the earth’s surface per second, yet virtually all pass through without interacting. Scientists can only detect them using very large detectors with exceptionally low background radiation levels. 

The Borexino detector lies deep under the Apennine Mountains in central Italy at the INFN’s Laboratori Nazionali del Gran Sasso. It detects neutrinos as flashes of light produced when neutrinos collide with electrons in 300-tons of ultra-pure organic scintillator. Its great depth, size, and purity make Borexino a unique detector for this type of science, alone in its class for low-background radiation, Pocar says. The project was initiated in the early 1990s by a group of physicists led by Gianpaolo Bellini at the University of Milan, Frank Calaprice at Princeton and the late Raju Raghavan at Bell Labs.

Until its latest detections, the Borexino collaboration had successfully measured components of the ‘proton-proton’ solar neutrino fluxes, helped refine neutrino flavor-oscillation parameters, and most impressively, even measured the first step in the cycle: the very low-energy ‘pp’ neutrinos, Pocar recalls.

Its researchers dreamed of expanding the science scope to also look for the CNO neutrinos – in a narrow spectral region with particularly low background – but that prize seemed out of reach. However, research groups at Princeton, Virginia Tech and UMass Amherst believed CNO neutrinos might yet be revealed using the additional purification steps and methods they had developed to realize the exquisite detector stability required.

Over the years and thanks to a sequence of moves to identify and stabilize the backgrounds, the U.S. scientists and the entire collaboration were successful. “Beyond revealing the CNO neutrinos which is the subject of this week’s Nature article, there is now even a potential to help resolve the metallicity problem as well,” Pocar says.

Before the CNO neutrino discovery, the lab had scheduled Borexino to end operations at the close of 2020. But because the data used in the analysis for the Nature paper was frozen, scientists have continued collecting data, as the central purity has continued to improve, making a new result focused on the metallicity a real possibility, Pocar says. Data collection could extend into 2021 since the logistics and permitting required, while underway, are non-trivial and time-consuming. “Every extra day helps,” he remarks.

Pocar has been with the project since his graduate school days at Princeton in the group led by Frank Calaprice, where he worked on the design, construction of the nylon vessel and the commissioning of the fluid handling system. He later worked with his students at UMass Amherst on data analysis and, most recently, on techniques to characterize the backgrounds for the CNO neutrino measurement.

Reference: “Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun” by The Borexino Collaboration, 25 November 2020, Nature.
DOI: 10.1038/s41586-020-2934-0

This work was supported in the U.S. by the National Science Foundation. Borexino is an international collaboration also funded by the Italian National Institute for Nuclear Physics (INFN), and funding agencies in Germany, Russia and Poland.

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