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2021 Astronomy Year In Review – Wawa-news.com – Wawa-news.com

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Looking back to 2021, there were many great space stories in the news including two lunar eclipses back in May and November. By coincidence, two more total lunar eclipses will occur in May and November 2022. We were also entertained by three great meteor showers in January, August and December but the moon ran major interference. The Northern Lights were prominent last month particularly in western Canada painting the sky green.

The never-ending list of exoplanets continues to grow with a total of 4,884 confirmed worlds and another 8,288 candidates. This search continues via ground and space-based telescopes. So, next time you look up at those twinkling points of light, you are looking at mini solar systems of at least one planet orbiting its parent star. After all the sun is but one of 300 billion stars in the Milky Way Galaxy.

It was this time last year that the Japanese Hayabusa mission successfully return soil samples from the asteroid Itokawa. The sample shows that water and organic matter that originate from the asteroid itself have evolved chemically through time. It has long been the thought of astronomers and scientists that building blocks of organic compounds needed to create life began in the solar system and was delivered to the young earth via meteorites. Missions such as this have shed new light on this theory. Meteorites and comets contain small amounts of water. Impacts over millions of years have most likely delivered water to the earth.

Comparable to the list of exoplanets, 70 more rogue planets have been detected floating through space. These are “outcasts” from their solar system by some event such as the star exploding thus launching it on a path to nowhere. Or some could have been overpowered by larger planets in their solar system and slingshot out of their system, from the light and (possible) warmth of their sun.

Until now, the sun has been studied by earth-bound telescopes and orbiting satellites. The amount of information learned is outstanding but the missing key was a physical examination. Never before has a spacecraft touched the sun until the Solar Parker Probe launched in 2018. Over the years the craft made multiple manoeuvres as it gets closer to the sun. In December of this year, the probe has touched the upper atmosphere of the sun’s corona which is only seen from Earth during a total solar eclipse when the moon blocks the blinding light. Over the next few years it will skim closer to our star and by the year 2025 is will be racing at an unheard of speed of 690,000 kilometres per hour or 192 kilometres per second. Its 11.4-centimetre thick heat shield alloys it to operate at about 29 degrees Celsius and not fry the electronics.

The newest addition to the Martian fleet came with the deployment of the SUV-sized rover Perseverance and Ingenuity helicopter anchored under it. The two blades of the small helicopter spin in opposite directions to help give lift in the thin Martian atmosphere. To date, it has logged 30 minutes in a series of short flights. This is the first time such a vehicle has been used on the red planet.

Private companies have proved they have the right stuff to launch into space, not just NASA. Jeff Bezos and Blue Origin allowed 90-year-old William Shatner and retired NFL Michael Strahan to touch space by past the 100 Karman Line. But Elon Musk has taken space travel one step further by transporting astronauts and supplies to the International Space Station via the SpaceX Dragon cargo ship. It is the same Dragon capsule that was almost used as an emergency escape vehicle. The International Space Station was subjected to a dangerous debris field of a purposely blown-up satellite. The danger has all but passed but there were some anxious moments.

Space is dangerous. Along with solar radiation from the sun and cosmic rays from the cosmos, more than 23,000 pieces of orbital debris larger than a softball are being tracked. Half a million pieces are the size of a marble or larger with approximately 100 million pieces of debris-about one millimetre and a bit larger. All moving at 28,000 km/hr or almost 8 km/sec.

In September of 2022, the DART mission will arrive at the 800-metre wide asteroid Didymos to deflect a small 160-metre wide moonlet Dimorphos. This is a test to see if a potential asteroid coming towards earth can be slightly deflected thus changing course and missing our planet. This particular asteroid is only a test subject and is no way on a collision course with our home planet.

The long-awaited James Webb Space Telescope (successor to the Hubble Space Telescope) was launched on Christmas Day. It has a much larger mirror system and will study infant galaxies in the near-infrared thus allowing us to see through the gas and dust of the earliest galaxies. The sun shield measures the size of a tennis court and will shade the telescope from the heat of the sun and block the light of the earth and moon. It will operate at a distance of 1.5 million kilometres from the earth where the temperature of space is -223 degrees Celsius. The JWST will be capable to look back to the beginning of the universe, some 13.8 billion years ago. One of its many projects will be to see if black holes helped create the galaxies or if they came afterwards. It will also look for signs of like in the atmospheres of distant exoplanets.

Known as “The Backyard Astronomer”, Gary Boyle is an astronomy educator, guest speaker and monthly columnist for the Royal Astronomical Society of Canada. He has been interviewed on more than 50 Canadian radio stations and local Ottawa TV. In recognition of his public outreach in astronomy, the International Astronomical Union has honoured him with the naming of Asteroid (22406) Garyboyle. Follow him on Twitter: @astroeducator or his website: www.wondersofastronomy.com

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Consistent asteroid showers rock previous thinking on Mars craters – Phys.org

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Credit: Curtin University

New Curtin University research has confirmed the frequency of asteroid collisions that formed impact craters on Mars has been consistent over the past 600 million years.

The study, published in Earth and Planetary Science Letters, analyzed the formation of more than 500 large Martian craters using a crater detection algorithm previously developed at Curtin, which automatically counts the visible impact craters from a high-resolution image.

Despite previous studies suggesting spikes in the of asteroid collisions, lead researcher Dr. Anthony Lagain, from Curtin’s School of Earth and Planetary Sciences, said his research had found they did not vary much at all for many millions of years.

Dr. Lagain said counting impact craters on a planetary surface was the only way to accurately date geological events, such as canyons, rivers and volcanoes, and to predict when, and how big, future collisions would be.

“On Earth, the erosion of plate tectonics erases the history of our planet. Studying planetary bodies of our Solar System that still conserve their early geological history, such as Mars, helps us to understand the evolution of our planet,” Dr. Lagain said.

“The detection algorithm provides us with a thorough understanding of the formation of impact craters including their size and quantity, and the timing and frequency of the asteroid collisions that made them.”

Past studies had suggested that there was a spike in the timing and frequency of asteroid collisions due to the production of debris, Dr. Lagain said.

“When big bodies smash into each other, they break into pieces or debris, which is thought to have an effect on the creation of impact craters,” Dr. Lagain said.

“Our study shows it is unlikely that debris resulted in any changes to the formation of on planetary surfaces.”

Co-author and leader of the team that created the algorithm, Professor Gretchen Benedix, said the algorithm could also be adapted to work on other planetary surfaces, including the Moon.

“The formation of thousands of lunar craters can now be dated automatically, and their formation frequency analyzed at a higher resolution to investigate their evolution,” Professor Benedix said.

“This will provide us with valuable information that could have future practical applications in nature preservation and agriculture, such as the detection of bushfires and classifying land use.”

The paper is titled “Has the impact flux of small and large asteroids varied through time on Mars, the Earth and the Moon?”


Explore further

Study pinpoints likely home of Martian meteorites


More information:
Anthony Lagain et al, Has the impact flux of small and large asteroids varied through time on Mars, the Earth and the Moon?, Earth and Planetary Science Letters (2022). DOI: 10.1016/j.epsl.2021.117362

Citation:
Consistent asteroid showers rock previous thinking on Mars craters (2022, January 21)
retrieved 22 January 2022
from https://phys.org/news/2022-01-asteroid-showers-previous-mars-craters.html

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Here’s why whales don’t drown when they gulp down food underwater — ScienceDaily – newsconcerns

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Ever wondered whether whales can burp, and why they don’t drown when they gulp down gallons of water and krill? New UBC research may just hold the answer.

Researchers found that lunge-feeding whales have an ‘oral plug’, a fleshy bulb in their mouths that moves backwards to seal off the upper airways during feeding, while their larynx closes to block the lower airways.

This plug prevents water from entering their lungs when they feed, according to a paper published today in Current Biology. “It’s kind of like when a human’s uvula moves backwards to block our nasal passages, and our windpipe closes up while swallowing food,” says lead author Dr. Kelsey Gil, a postdoctoral researcher in the department of zoology.

Lunge-feeding whales eat by, you guessed it, lunging at their prey, accelerating at high speed and opening their mouths to engulf water and krill. Sometimes this amount can be larger than their own bodies, says Dr. Gil, an impressive feat given this group includes the humpback and the blue whale, the largest animal on Earth. Water is then drained via their baleen, leaving the tiny, tasty krill behind to be swallowed.

The researchers investigated fin whales specifically, a type of lunge-feeding whale and found the ‘oral plug’ needed to move in order to allow food to pass to the esophagus. The only way it could was towards the back of the head, and up, blocking off the nasal passages when the whale swallows. Simultaneously, cartilage closes at the entrance to the larynx, and the laryngeal sac moves upwards to block off the lower airways, says Dr. Gil. “We haven’t seen this protective mechanism in any other animals, or in the literature. A lot of our knowledge about whales and dolphins comes from toothed whales, which have completely separated respiratory tracts, so similar assumptions have been made about lunge-feeding whales.”

It turns out humans have a similar system to swallow food without getting anything in their lungs: we have the epiglottis and soft palate, a ‘lid’ of cartilage and a flap of muscle in our throat and mouth, respectively. Humans could probably eat underwater as well, says Dr. Gil, but it would be rather like swimming at high speed towards a hamburger and opening your mouth wide as you approached — difficult not to flood your lungs.

The whales’ oral plug and closing larynx is central to how lunge-feeding evolved, a key component in the enormous size of these creatures, the researchers say. “Bulk filter-feeding on krill swarms is highly efficient and the only way to provide the massive amount of energy needed to support such large body size. This would not be possible without the special anatomical features we have described,” says senior author Dr. Robert Shadwick, a professor in the UBC department of zoology.

Investigating whale anatomy often involves trying to dissect whales that have died from stranding which comes with such challenges as trying to complete work before the tide rises. However, for this research, Dr. Gil and her colleagues dissected whales in Iceland in 2018, recovering tissue that wasn’t being used for food from a commercial whaling station. Working with whales in real-time would be wonderful, she says, but might require some advancements in technology. “It would be interesting to throw a tiny camera down a whale’s mouth while it was feeding to see what’s happening, but we’d need to make sure it was safe to eat and biodegradable.”

The team will continue to explore the mechanisms related to the pharynx, and of the small esophagus that is responsible for rapidly transporting hundreds of kilograms of krill to the stomach in less than a minute. With the many human impacts that disrupt food chains, and knowing how whales feed and how much they eat, it’s good to know as much as possible about these animals in order to protect them and their eco systems, says Dr. Gil.

And there’s plenty more to find out, including whether whales cough, hiccup, and yes, burp. “Humpback whales blow bubbles out of their mouth, but we aren’t exactly sure where the air is from — it might make more sense, and be safer, for whales to burp out of their blowholes.”

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The drifting giant A68 iceberg released billions of tons of fresh water in South Georgia ecosystem – MercoPress

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Saturday, January 22nd 2022 – 10:56 UTC

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Satellite images shows A68a heading towards the sub-Antarctic island of South Georgia. Credit: MODIS from NASA Worldview Snapshots

Scientists monitoring the giant A68a iceberg from space reveal that a huge amount of freshwater was released as it melted around the sub-Antarctic island of South Georgia. An estimated 152 billion tons of freshwater – equivalent to 20 x Loch Ness or 61 million Olympic sized swimming pools, entered the seas around the sub-Antarctic island of South Georgia when A68a melted over three months in 2020/2021, according to a new study published this month by the British Antarctic Survey.

In July 2017, A68a calved off the Larsen-C Ice Shelf on the Antarctic Peninsula and began its epic three-and-a-half year, 4.000 km journey across the Southern Ocean. At 5719 square kilometers – about a quarter the size of Wales – it was the biggest iceberg on Earth when it formed and the sixth largest on record. Around Christmas 2020, the berg received widespread attention as it drifted worryingly close to South Georgia, raising concerns it could harm the island’s fragile ecosystem.

A team from Center for Polar Observation and Modeling and BAS used satellite measurements to chart the iceberg’s area and thickness change throughout its life cycle. The authors show that the iceberg had melted enough as it drifted to avoid damaging the sea floor around South Georgia by running aground. However, a side effect of the melting was the release of a colossal 152 billion tons of fresh water in close proximity to the island – a disturbance that could have a profound impact on the island’s marine habitat.

For the first two years of its life, A68a stayed close to Antarctica in the cold waters of the Weddell Sea and experienced little in the way of melting. However, once it began its northwards journey across the Drake Passage it traveled through increasingly warm waters and began to melt. Altogether, the iceberg thinned by 67 meters from its initial 235 m thickness, with the rate of melting rising sharply as the berg drifted around South Georgia.

Laura Gerrish, GIS and mapping specialist at BAS and co-author of the study said, “A68 was an absolutely fascinating iceberg to track all the way from its creation to its end. Frequent measurements allowed us to follow every move and break-up of the berg as it moved slowly northwards through an area called ‘iceberg alley’, a route in the ocean which icebergs often follow, and into the Scotia Sea where it then gained speed and approached the island of South Georgia very closely.”

If an iceberg’s keel is too deep it can become grounded on the sea floor. This can be disruptive in several different ways; the scour marks can destroy fauna, and the berg itself can block ocean currents and predator foraging routes. All of these potential outcomes were feared when A68a approached South Georgia. However, this new study reveals that it collided only briefly with the sea floor and broke apart shortly afterwards, making it less of a risk in terms of blockage. By the time it reached the shallow waters around South Georgia, the iceberg’s keel had reduced to 141 meters below the ocean surface, shallow enough to avoid the seabed which is around 150 meters deep.

Nevertheless, the ecosystem and wildlife around South Georgia will certainly have felt the impact of the colossal iceberg’s visit. When icebergs detach from ice shelves, they drift with the ocean currents and wind while releasing cold fresh melt-water and nutrients as they melt. This process influences the local ocean circulation and fosters biological production around the iceberg. At its peak, the iceberg was melting at a rate of 7 meters per month, and in total it released a staggering 152 billion tons of fresh water and nutrients.

“This is a huge amount of melt water, and the next thing we want to learn is whether it had a positive or negative impact on the ecosystem around South Georgia. Because A68a took a common route across the Drake Passage, we hope to learn more about icebergs taking a similar trajectory, and how they influence the polar oceans,” said Anne Braakmann-Folgmann, a researcher at CPOM and PhD candidate at the University of Leeds’ School of Earth and Environment, and lead author of the study.

The journey of A68a has been charted using observations from five different satellites. The iceberg’s area change was recorded using a combination of Sentinel-1, Sentinel-3, and MODIS imagery. Meanwhile, the iceberg’s thickness change was measured using CryoSat-2 and ICESat-2 altimetry. By combining these measurements, the iceberg’s area, thickness, and volume change were determined.

Tommaso Parrinello, CryoSat Mission Manager at the European Space Agency pointed out that “Our ability to study every move of the iceberg in such detail is thanks to advances in satellite techniques and the use of a variety of measurements. Imaging satellites record the location and shape of the iceberg and data from altimetry missions add a third dimension as they measure the height of surfaces underneath the satellites and can therefore observe how an iceberg melts.”

“Observing the Disintegration of the A68A Iceberg from Space” is published in the journal Remote Sensing of Environment at https://doi.org/10.1016/j.rse.2021.112855.

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