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In death of dinosaurs, it was all about the asteroid—not volcanoes – Phys.org

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Credit: CC0 Public Domain

Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.

In a break from a number of other recent studies, Yale assistant professor of geology & geophysics Pincelli Hull and her colleagues argue in a new research paper in Science that environmental impacts from in India in the region known as the Deccan Traps happened well before the Cretaceous-Paleogene event 66 million years ago and therefore did not contribute to the .

Most scientists acknowledge that the , also known as K-Pg, occurred after an asteroid slammed into Earth. Some researchers also have focused on the role of volcanoes in K-Pg due to indications that happened around the same time.

“Volcanoes can drive mass extinctions because they release lots of gases, like SO2 and CO2, that can alter the climate and acidify the world,” said Hull, lead author of the new study. “But recent work has focused on the timing of lava eruption rather than gas release.”

To pinpoint the timing of volcanic gas emission, Hull and her colleagues compared and the (an isotope is an atom with a higher or lower number of neutrons than normal) from marine fossils with models of the climatic effect of CO2 release. They concluded that most of the gas release happened well before the asteroid impact—and that the asteroid was the sole driver of extinction.

“Volcanic activity in the late Cretaceous caused a gradual global warming event of about two degrees, but not mass extinction,” said former Yale researcher Michael Henehan, who compiled the temperature records for the study. “A number of species moved toward the North and South poles but moved back well before the asteroid impact.”

Added Hull, “A lot of people have speculated that volcanoes mattered to K-Pg, and we’re saying, ‘No, they didn’t.'”

Recent work on the Deccan Traps, in India, has also pointed to massive eruptions in the immediate aftermath of the K-Pg mass extinction. These results have puzzled scientists because there is no warming event to match. The new study suggests an answer to this puzzle, as well.

“The K-Pg extinction was a mass extinction and this profoundly altered the global carbon cycle,” said Yale postdoctoral associate Donald Penman, the study’s modeler. “Our results show that these changes would allow the ocean to absorb an enormous amount of CO2 on long time scales—perhaps hiding the warming effects of volcanism in the aftermath of the event.”


Explore further

Fossilized seashells show signs of ocean acidification before dinosaur-annihilating asteroid


More information:
P.M. Hull el al., “On impact and volcanism across the Cretaceous-Paleogene boundary,” Science (2019). science.sciencemag.org/cgi/doi … 1126/science.aay5055

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In death of dinosaurs, it was all about the asteroid—not volcanoes (2020, January 16)
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Hubble Looks at Spiral Galaxy NCG 7329 – Sci-News.com

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The NASA/ESA Hubble Space Telescope has captured an amazing photo of the spiral galaxy NCG 7329.

This Hubble image shows NCG 7329, a spiral galaxy located some 149 million light-years away in the constellation of Tucana. Image credit: NASA / ESA / Hubble / Riess et al.

NCG 7329 was first discovered by the English astronomer John Herschel on July 20, 1835.

Otherwise known as ESO 109-12, IRAS 22369-6644 and LEDA 69453, it resides 149 million light-years away in the constellation of Tucana.

The galaxy is a member of the NGC 7329 group (LGG 462), an assembly of more than 10 galaxies bound together by gravity.

This new image of NCG 7329 is made up of observations from Hubble’s Wide Field Camera 3 (WFC3) in the infrared and optical parts of the spectrum.

“Creating a colorful image such as this one using a telescope such as Hubble is not as straightforward as pointing and clicking a camera,” Hubble astronomers said.

“Commercial cameras will typically try to collect as much light of all visible wavelengths as they can, in order to create the most vibrant images possible.”

“In contrast, raw images collected by Hubble are always monochromatic, because astronomers typically want to capture very specific ranges of wavelengths of light at any time, in order to do the best, most accurate science possible.”

“In order to control which wavelengths of light will be collected, Hubble’s cameras are equipped with a wide variety of filters, which only allow certain wavelengths of light to reach the cameras’ CCDs (a CCD is a camera’s light sensor — phone cameras also have CCDs).”

“How are the colorful Hubble images possible given that the raw Hubble images are monochromatic? This is accomplished by combining multiple different observations of the same object, obtained using different filters,” they added.

“This image of NCG 7329, for example, was processed from Hubble observations made using four different filters, each of which spans a different region of the light spectrum.”

“Specialized image processors and artists can make informed judgements about which optical colors best correspond to each filter used.”

“They can then color the images taken using that filter accordingly.”

“Finally, the images taken with different filters are stacked together, and voila!”

“The colorful image of a distant galaxy is complete, with colors as representative of reality as possible.”

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SpaceX Tapped For 3 More Possible Commercial Crew Flights To Space – Forbes

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SpaceX’s Crew Dragon is just going to get busier shuttling astronauts in the coming years.

NASA announced it intends to issue a sole-source modification to SpaceX’s long-term contract to send astronauts to the International Space Station. This follows an agency call for proposals back in October for more flight options to send people to space.

Boeing’s Starliner spacecraft, which is the other major system, is not quite yet ready for humans following a difficult uncrewed test flight in 2019 that never saw the spacecraft reach the ISS. Starliner has spent some time fixing computer glitches and other issues (including a valve problem that delayed an expected 2021 launch) and is now expecting a second uncrewed test flight by 2022.

The October solicitation, NASA noted, confirms SpaceX is the only viable choice for the time being, given the agency’s safety requirements and the need to keep the space station staffed continuously in the coming years.

“It’s critical we begin to secure additional flights to the space station now so we are ready as these missions are needed to maintain a U.S. presence on station,” Kathy Lueders, associate administrator of NASA’s space 0perations mission directorate, said in a blog post. “Our U.S. human launch capability is essential to our continued safe operations in orbit and to building our low-Earth orbit economy.”

NASA stated it would use these new flights “as early as 2023”, and that the contract (in securing flights and allowing the agency to task personnel elsewhere) will help them get Boeing’s Starliner system ready to fly astronauts once it’s been certified.

“NASA and Boeing will provide additional updates on the status of Starliner’s next mission as we work through the investigation and verification efforts to determine root cause and effective vehicle remediation,” said Phil McAlister, director of commercial spaceflight at NASA, in the same statement.

The latest issue holding up the flight was an oxidizer isolation valve that was found in August, and NASA and Boeing together elected to pull the spacecraft back to the hanger to figure out how to fix the issue before sending the spacecraft aloft.

Another pressing issue for NASA’s future will be extending the planned retirement of the ISS from 2024 to at least 2028, which the agency has said for years it wants to do. It is in negotiations with Congress and with its international partners to do this, and in the meantime, last week the agency also announced it has secured three early-stage contracts for future private space stations to fly late in the 2020s.

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See what food challenges astronauts face in space – CGTN America

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For the first time ever, NASA and the Canadian Space Agency hosted the Deep Space Food Challenge. 

The competition brought universities and companies together to propose solutions on how to feed astronauts on a long mission. Last month, NASA announced that the winners and one of the international winners of the Phase 1 competition came from a group of students in a university in South America. 

CGTN’s Michelle Begue reports Colombia.

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