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New Trilobites Fossil Revealed a Resemblance to Modern Crustaceans – Nature World News

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According to a recent study, trilobites, ancient marine arthropods that lived from 520 million years ago until their extinction 250 million years ago at the end of the Permian epoch, may have developed similarly to modern crustaceans and reached ages that are comparable to them.

Relationship of trilobites to modern crustaceans

(Photo : Pavel Polívka/Unsplash)

Researchers from the University of British Columbia and Uppsala University demonstrated in a study that was published in the journal Paleobiology that the Ordovician trilobite, Triarthrus eatoni, which lived 450 million years ago, reached a length of just over four centimeters in about 10 years, and had a growth curve resembling to that of small, slow-growing crustaceans.

T. eatoni lived in low-oxygen environments and, like extant crustaceans exposed to hypoxic conditions, showed low growth rates compared with growth under more oxygenated conditions, according to Daniel Pauly, principal investigator of UBC’s Sea Around Us initiative and lead author of the study, as cited by ScienceDaily.

Low-oxygen environments make it harder for water breathers to develop and add to the challenges of inhaling through gills, which, as 2D surfaces, cannot keep up with their 3D bodies.

Therefore, in order to sustain the remainder of their bodily processes under hypoxic conditions, they must continue to be little.

Trilobites had exopods, which were external branches on the tops of their limbs, which served as gills.

Therefore, the development restrictions on these extinct species were comparable to those on their living relatives.

Pauly and paleontologist James Holmes, a colleague from Uppsala University, used the analysis of length-frequency data, a technique created in the fields of fisheries science and marine biology for examining the growth of fish and invertebrates lacking the physical markings that serve as age markers.

Also Read: Trilobites Possessed Clasper-like Limbs for Mating, According To Fossil Discoveries

Trilobites as an arthropod

The zoological affiliations of trilobites may be established from features retained in fossils despite a quarter billion years since their demise, as per the Australian Museum.

Trilobita were generally known to belong to the Arthropoda before the first trilobite with its legs fossilized was reported in 1870.

Since the Early Cambrian, arthropods have been the most varied phylum of multicellular organisms and have the greatest number of species.

Their primary subdivisions include the crustaceans, which include millipedes and centipedes; the chelicerates, which include spiders, scorpions, and mites; and the entirely terrestrial families Insecta and Myriapoda.

The group of extinct arthropods with the largest species diversity is the trilobita.

The hard exoskeleton that covered the dorsal body surface of trilobites and its distinct segmentation (such as the jointed segments of the thorax) are typical arthropod characteristics.

The calcite-based trilobite exoskeleton was mineralized.

The labrum, a similar feature seen in other arthropods, is analogous to the trilobite hypostome, a plate affixed to the lower side of the head right in front of the mouth opening.

Most trilobites have two compound eyes, and the way their ommatidia are arranged is typical of arthropods.

To accommodate development, trilobites regularly shed their exoskeleton.

Trilobite fossils occasionally contain so-called molt configurations, which depict different phases of the animal’s exoskeleton being released and its subsequent escape.

Another defining trait of arthropods is molting. The majority of trilobites shed their skin by severing the head shield at weak points (known as facial sutures) that run parallel to the eye’s visible surface.

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Related article: Fossil of 390-Million-Year-Old Ancient Arthropod with Tiny Eyes Inside its Eyes Unearthed

© 2022 NatureWorldNews.com All rights reserved. Do not reproduce without permission.

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NASA’s DART spacecraft is about to smash into an asteroid – Freethink

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NASA’s Double Asteroid Redirection Test (DART) has gotten its first look at the Didymos asteroid system — and in just a few days, it will attempt to smash into one of the space rocks in the hope of helping NASA prevent a future asteroid impact with Earth. 

The challenge: Our solar system contains millions of rocky objects left over after the formation of the planets and moons. The biggest of these are asteroids, and while most never get close to us, if a large one were to hit Earth’s surface, the impact could be devastating.

NASA keeps an eye out for potentially hazardous asteroids, and if it saw one heading our way, we might be able to prevent the collision by slamming something into the threatening space rock to redirect it — but no one has attempted an asteroid-redirection mission before, so we don’t know for sure how or if it would work.

“This first set of images is being used as a test to prove our imaging techniques.”

Elena Adams

The DART spacecraft: Since we wouldn’t want to wait until our planet is at risk to find out whether it is possible to redirect an asteroid, NASA launched DART, the world’s first planetary defense experiment, in November 2021. 

The DART spacecraft is expected to make impact with Dimorphos, a small asteroid orbiting the larger Didymos asteroid, on September 26, 2022, when the pair are about 7 million miles from Earth — nowhere near close enough to harm our planet.

NASA will then use data from the collision to inform future asteroid redirection experiments and, if needed, actual planetary defense missions.

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Eyes on the prize: During its 10-month journey to the Didymos asteroid system, the DART spacecraft has used an imager, DRACO (Didymos Reconnaissance and Asteroid Camera for Optical navigation), to snap thousands of photos.

By combining nearly 250 images captured by DRACO on July 27, 2022, NASA has produced DART’s first image of Didymos and Dimorphos.

This image of Didymos and its moonlet Dimorphos is a composite of 243 images taken by DRACO. Credit: NASA JPL DART Navigation Team

Why it matters: DART’s ability to capture and process images of its target using DRACO is essential to the success of the mission — in the final four hours before impact, the DART spacecraft will need to navigate to the asteroids without human intervention, and those images will be vital to ensuring it hits its target.

“This first set of images is being used as a test to prove our imaging techniques,” said Elena Adams, the DART mission systems engineer at the Johns Hopkins Applied Physics Laboratory.

“The quality of the image is similar to what we could obtain from ground-based telescopes,” she continued, “but it is important to show that DRACO is working properly and can see its target to make any adjustments needed before we begin using the images to guide the spacecraft into the asteroid autonomously.”

We’d love to hear from you! If you have a comment about this article or if you have a tip for a future Freethink story, please email us at [email protected].

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N.W.T. man among finalists in international astronomy photographer contest

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YELLOWKNIFE — A man from Yellowknife is gaining international recognition for a photo capturing a stunning display of dancing green aurora lights over the Cameron River.

Frank Bailey was the only Canadian among the finalists in the Royal Observatory Greenwich’s 2022 Astronomy Photographer of the Year competition. His time-lapse photo taken outside the Northwest Territories capital landed him the runner-up spot in the Aurorae category.

“I was of course thrilled, but also humbled at the news given the quality of the entries this year,” he said. “Once the overall standings were made fully public, it sunk in really quickly that this was a significant achievement and shows that I am heading in the right direction with my photography.”

The annual competition is the largest of its kind and showcases space and sky photography from astrophotographers around the world. More than 100 winning and shortlisted images from this year’s entries are currently on display at the National Maritime Museum in London, featuring planets, galaxies, skyscapes and other celestial bodies.

Gerald Rhemann from Austria was named the overall winner for his photo of Comet C/2021 A1, commonly known as Comet Leonard.

The top spot in the Aurorae category went to Filip Hrebenda for his photo titled “In the Embrace of a Green Lady,” showing the lights reflected in a frozen lake above Eystrahorn mountain in Hvalnes, Iceland.

Bailey’s photo, titled “Misty Green River,” was taken last September using a 15-second exposure. He said the photo was taken looking up the river toward the riffle as mist rose off the water.

Bailey, who has lived in Yellowknife for 18 years, said he first photographed the aurora when he and his wife, Karen, lived in Yukon in the early 1980s.

He said he likes to enter competitions to get feedback on his photography.

“As for future goals, I have always said it would be a good retirement job,” he said, noting he and his wife have dabbled with making sellable products such as calendars and producing prints for friends and family.

Another photo Bailey took of the aurora over the Cameron River, which he submitted to the National Wildlife Federation’s photo contest in 2020, was selected for use in a holiday card collection.

He said three of his aurora photos received a bronze award from the Epson International Pano Awards in 2021.

This report by The Canadian Press was first published Sept. 24, 2022.

This story was produced with the financial assistance of the Meta and Canadian Press News Fellowship.

 

Emily Blake, The Canadian Press

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Tonga volcano blast was unusual, could even warm the Earth – Kelowna Capital News – Kelowna Capital News

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When an undersea volcano erupted in Tonga in January, its watery blast was huge and unusual — and scientists are still trying to understand its impacts.

The volcano, known as Hunga Tonga-Hunga Ha’apai, shot millions of tons of water vapor high up into the atmosphere, according to a study published Thursday in the journal Science.

The researchers estimate the eruption raised the amount of water in the stratosphere — the second layer of the atmosphere, above the range where humans live and breathe — by around 5%.

Now, scientists are trying to figure out how all that water could affect the atmosphere, and whether it might warm Earth’s surface over the next few years.

“This was a once-in-a-lifetime event,” said lead author Holger Voemel, a scientist at the National Center for Atmospheric Research in Colorado.

Big eruptions usually cool the planet. Most volcanoes send up large amounts of sulfur, which blocks the sun’s rays, explained Matthew Toohey, a climate researcher at the University of Saskatchewan who was not involved in the study.

The Tongan blast was much soggier: The eruption started under the ocean, so it shot up a plume with much more water than usual. And since water vapor acts as a heat-trapping greenhouse gas, the eruption will probably raise temperatures instead of lowering them, Toohey said.

It’s unclear just how much warming could be in store.

Karen Rosenlof, a climate scientist at the National Oceanic and Atmospheric Administration who was not involved with the study, said she expects the effects to be minimal and temporary.

“This amount of increase might warm the surface a small amount for a short amount of time,” Rosenlof said in an email.

The water vapor will stick around the upper atmosphere for a few years before making its way into the lower atmosphere, Toohey said. In the meantime, the extra water might also speed up ozone loss in the atmosphere, Rosenlof added.

But it’s hard for scientists to say for sure, because they’ve never seen an eruption like this one.

The stratosphere stretches from around 7.5 miles to 31 miles (12 km to 50 km) above Earth and is usually very dry, Voemel explained.

Voemel’s team estimated the volcano’s plume using a network of instruments suspended from weather balloons. Usually, these tools can’t even measure water levels in the stratosphere because the amounts are so low, Voemel said.

Another research group monitored the blast using an instrument on a NASA satellite. In their study, published earlier this summer, they estimated the eruption to be even bigger, adding around 150 million metric tons of water vapor to the stratosphere — three times as much as Voemel’s study found.

Voemel acknowledged that the satellite imaging might have observed parts of the plume that the balloon instruments couldn’t catch, making its estimate higher.

Either way, he said, the Tongan blast was unlike anything seen in recent history, and studying its aftermath may hold new insights into our atmosphere.

—Maddie Burakoff, The Associated Press

RELATED: Flights sent to assess Tonga damage after volcanic eruption

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