On September 29, 2024, something unusual happened in our cosmic neighborhood. Earth captured a tiny asteroid named 2024 PT5, turning it into a temporary mini-moon. 



That's right... as of today, November 2, 2024, <a href="https://www.earth.com/news/its-official-earth-now-has-two-moons-captured-asteroid-2024-pt5/" target="_blank" rel="noreferrer noopener">Earth has two moons</a>.



Richard Binzel, an astronomer at the Massachusetts Institute of Technology (<a href="https://www.mit.edu" target="_blank" rel="noreferrer noopener">MIT</a>), shed some light on these fleeting celestial companions.



"These happen more often than we think, but they're small and tough to spot," Binzel explained. "Only lately have our telescopes become powerful enough to catch them regularly."



Back in August, a team of astronomers from the <a href="https://www.ucm.es/english" target="_blank" rel="noreferrer noopener">Complutense University</a> of Madrid detected the small space rock using a powerful telescope in Sutherland, South Africa.



They weren't the only ones keeping an eye on it. The asteroid was first noticed on August 7, 2024 by NASA's Asteroid Terrestrial-impact Last Alert System (<a href="https://atlas.fallingstar.com/" target="_blank" rel="noreferrer noopener">ATLAS</a>) at Haleakala Observatory in Hawaii.



This discovery sparked excitement among astronomers, offering a chance to learn more about <a href="https://www.earth.com/news/nasa-test-simulation-shows-earth-not-prepared-prevent-large-asteroid-strike/" target="_blank" rel="noreferrer noopener">near-Earth objects</a>.



<h2 class="wp-block-heading" id="h-what-exactly-is-2024-pt5">What exactly is 2024 PT5?</h2>



Earth occasionally captures small asteroids like 2024 PT5, placing them into temporary orbits around our planet. 



While most asteroids circle the sun on their regular paths, some venture close enough for <a href="https://www.earth.com/news/earth-global-electric-field-discovered-equally-important-gravity-magnetic-fields/" target="_blank" rel="noreferrer noopener">Earth's gravity</a> to snatch them up for a brief visit.



These cosmic visitors only stay in Earth's orbit for a short time -- typically a few weeks or months -- before breaking free and resuming their solar journey.



Each mini-moon gives scientists a rare opportunity to examine <a href="https://www.earth.com/news/27500-hidden-near-earth-asteroids-discovered-using-google-cloud/" target="_blank" rel="noreferrer noopener">near-Earth asteroids</a> up close, revealing valuable insights about our solar system's mechanics.



So, what makes this asteroid special, aside from the fact that new technology and the internet made it famous? 



William Blackmore, Planetarium Director and Astronomy Instructor at <a href="https://www.mhcc.edu/" target="_blank" rel="noreferrer noopener">Mt. Hood Community College</a>, offered his thoughts.



"All mini-moons are unique in their own way," Blackmore explained. "This one isn't different from others except that it's the most recent.”



2024 PT5 will be around for about two more weeks, probably until mid-November.



<h2 class="wp-block-heading" id="h-comparing-2024-pt5-to-our-moon">Comparing 2024 PT5 to our moon</h2>



Let's compare our moon to this new mini-moon: 2024 PT5 is only about 37 feet across, while our familiar moon stretches a massive 2,159 miles in diameter. That makes <a href="https://www.earth.com/news/how-did-earth-get-its-moon-a-new-theory-has-emerged/" target="_blank" rel="noreferrer noopener">our moon</a> over 300,000 times wider than this tiny asteroid.



Knowing it’s up there is pretty exciting, even though we can't see it for ourselves without an invitation to a huge Earth telescope installation.



“These temporary captures are natural cosmic laboratories,” Binzel mentioned. “They help us understand the small bodies that come close to Earth and could be important for future space missions.”



<h2 class="wp-block-heading" id="h-how-asteroid-2024-pt5-became-famous">How Asteroid 2024 PT5 became famous</h2>



Understanding how 2024 PT5 became Earth's temporary moon involves a bit of <a href="https://www.earth.com/news/finding-order-in-the-chaos-of-the-three-body-problem/" target="_blank" rel="noreferrer noopener">orbital mechanics</a>. 



Blackmore explained, "It's moving along with us in our orbit around the sun. It's part of a group of asteroids called the Arjuna asteroids, which move at about the same pace as Earth."



He added an interesting analogy: "Imagine a skateboarder dropping into a skate park. They ride the curves, adding energy as they go. That's like the asteroid getting caught in <a href="https://www.earth.com/news/dart-mission-debris-will-create-a-human-made-meteor-shower/" target="_blank" rel="noreferrer noopener">Earth's gravitational field</a>, riding the curve before moving on."



<h2 class="wp-block-heading" id="h-significance-of-spotting-mini-moons">Significance of spotting mini-moons</h2>



Spotting mini-moons is tough because they're incredibly small and faint. These tiny asteroids are often just a few dozen feet across, which means they don't reflect much sunlight. That makes them nearly invisible against the dark backdrop of space.



Plus, they're zipping around at high speeds and don't hang around for long, so by the time we point our telescopes their way, they might already be gone. 



It's like trying to catch a glimpse of a firefly from miles away -- you need the right conditions and equipment.



<h2 class="wp-block-heading" id="h-modern-high-tech-telescopes">Modern high-tech telescopes</h2>



Astronomers find them by using powerful telescopes equipped with <a href="https://www.earth.com/news/gaia-reveals-moons-around-hundreds-of-asteroids/" target="_blank" rel="noreferrer noopener">sensitive detectors and smart software</a>.



Projects like the ATLAS system scan the skies every night, searching for any objects that weren't there before. 



When they spot something moving in a way that suggests it's close to Earth, they alert other astronomers to help confirm the find. 



It's a collaborative effort, combining technology and teamwork to spot these elusive cosmic visitors.



Knowing more about these temporary moons helps us prepare for any potential asteroid threats and opens up possibilities for mining resources from near-Earth objects.



<h2 class="wp-block-heading" id="h-challenges-in-observing-2024-pt5">Challenges in observing 2024 PT5</h2>



For those eager to see this mini-moon, both experts warned that it would be extremely difficult. "You'd need a telescope with a diameter of at least 30 inches," Blackmore mentioned. "That's beyond what most amateur astronomers have."



Todd agreed, adding, "It won't be visible to the naked eye. Being 33 feet wide and so far away, you'd need a very large telescope."



<h2 class="wp-block-heading" id="h-why-does-any-of-this-matter">Why does any of this matter?</h2>



While 2024 PT5 doesn't pose any threat to Earth, <a href="https://www.earth.com/news/is-there-a-fifth-force-of-nature-asteroids-provide-new-clues/" target="_blank" rel="noreferrer noopener">studying it is crucial</a>. 



"It's important to analyze how it moves and interacts with Earth's gravitational pull," Blackmore said. "This helps us refine our techniques for tracking objects that could cross our path again."



Todd highlighted the practical applications of this knowledge. 



"We need to understand how to intercept an asteroid at a distance and change its direction," he said. "This could be vital in <a href="https://www.earth.com/news/nasa-dart-mission-proves-humanity-can-be-saved-from-asteroid-collision/" target="_blank" rel="noreferrer noopener">preventing potential impacts</a> in the future."



<h2 class="wp-block-heading" id="h-inspiration-for-future-space-missions">Inspiration for future space missions</h2>



Blackmore envisioned future missions that could take advantage of these temporary visitors. 



"It would be fascinating if we had missions ready to send small satellites or probes to these objects when they come close," he mused. "Imagine building a network of sensors or cameras traveling along with us, like space webcams."



Todd also saw <a href="https://www.earth.com/news/asteroid-named-psyche-is-worth-10000-quadrillion-for-whoever-can-extract-minerals/" target="_blank" rel="noreferrer noopener">potential in asteroid mining</a> and scientific discovery. 



"There might be materials on these asteroids that we can't find on Earth," he said. "They could solve problems in medicine or technology. But we need to weigh the benefits carefully."



To sum it all up, the brief visit of asteroid 2024 PT5 serves as a reminder of the dynamic <a href="https://www.earth.com/news/building-blocks-of-life-found-in-asteroids-were-formed-in-cold-regions-of-space/" target="_blank" rel="noreferrer noopener">nature of our solar system</a>. 



While it won't be with us for long -- just a couple more weeks -- its presence offers valuable opportunities for learning and exploration.



As technology advances, we'll likely spot more of these mini-moons. Each one gives us a chance to understand our cosmic environment better and prepare for the future. 



So even though you'll never see it, you might want to spare a moment of your time and stop to appreciate 2024 PT5 while you still can.



The full study was published in the&nbsp;<a href="https://iopscience.iop.org/article/10.3847/2515-5172/ad781f" target="_blank" rel="noreferrer noopener">journal IOPscience</a>.



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Earth's second moon, a mini-moon, will drift away in a few days and never return

On September 29, 2024, something unusual happened in our cosmic neighborhood. Earth captured a tiny asteroid named 2024 PT5, turning it into a temporary mini-moon. That's right... as of today, November 2, 2024, Earth has two moons. Richard Binzel, an astronomer at the Massachusetts Institute of Technology (MIT), shed some light on these fleeting celestial companions. "These happen more often than we think, but they're small and tough to spot," Binzel explained. "Only lately have our telescopes become powerful enough to catch them regularly." Back in August,...

Free-range hens are often healthier birds – and it shows in their eggs, according to a new study.

Researchers from <a href="http://www.reading.ac.uk/">Reading University</a> studied 270 eggs from supermarkets in the United Kingdom. They found that the yolks of eggs from free-range hens had about 30 percent more vitamin D than eggs from hens kept indoors or in cages.

The vitamin usually comes from sunlight, and free-range birds allowed to wander outdoors get a lot more of it than their caged colleagues. 

Vitamin D can help prevent certain cancers, heart disease and diabetes. It’s found in only a few foods, including egg yolks, oily fish and liver. Otherwise, it comes primarily from the sun or supplements.

In the UK, where the study was conducted, millions of people develop vitamin D deficiencies during the winter months, when sunlight is scarce and people spend more time indoors, the researchers said.

Hens that have access to the outdoor runs and vegetation – and more sunlight – produce eggs high in the vitamin. But organic farms where hens have the most freedom and lowest amounts of genetically modified feed also have a spike in a form of the vitamin called 25-hydroxy D3, which is especially beneficial to human health, the scientists said.

Free-range and organic eggs account for about half of the eggs sold in the UK. The rest come from large egg farms where the chickens are kept in barns, usually in “colony cages” that allow perching and nesting, but no access to the outdoors.

The barn eggs generally contain about 1.7 micrograms of vitamin D, compared to 2 micrograms in free-range eggs and 2.2 in organic eggs. UK health officials recommend 10 micrograms of vitamin D per day for adults, and 7 to 8.5 micrograms for children.

Robert Brown of the McCarrison Society, a nutritional think tank, said the study is not surprising. Hens naturally (and domestically, until after World War II) had access to the outdoors and natural foods, he said. Putting them in industrial sheds allows farms to produce more eggs at lower expense, but it can also lower eggs’ health benefits, he added. 

Jon Walton of the <a href="https://www.soilassociation.org/">Soil Association</a> agreed. Organic agricultural operations put animal welfare first, he said, and their animals live a healthier, more natural life. 

The study was published in the journal Food Chemistry.

Study finds eggs from free-range hens may be better for you

Free-range hens are often healthier birds – and it shows...

The mayors of four major international cities have unveiled plans for a diesel ban by 2025. 

To prepare for the diesel ban, the leaders of Mexico City, Paris, Madrid, and Athens plan to offer incentives to those who switch to alternative vehicles, and to launch campaigns encouraging walking and cycling.

The mayors committed to a move away from diesel at the sixth biennial <a href="http://www.c40.org/">C40 Mayors Summit</a> in Mexico City. C40 is a network of more than 80 megacities that have joined together to try to fight pollution. C40 represents more than 600 million city residents worldwide.

The cities are banding against diesel after the fuel came under fire from the <a href="http://www.who.int/en/">World Health Organization</a> for adding to air pollution. While more fuel efficient, diesel exhaust contains more nitrogen oxides than other vehicle types. Nitrogen oxides are linked to higher rates of asthma, lung disease, and heart disease.

It also contains particulate matter such as fine soot, which can enter the lungs and cause lung and heart disease and death.

WHO has linked about three million deaths each year to air pollution.

As evidence of the harm caused by air pollution mounts, more cities and nations are taking step to reduce the problem. Mexico City, Paris, Madrid and Athens are vowing to encourage drivers to switch from diesel to electric, hydrogen, and hybrid vehicles, including incentives programs.

Mexico City’s mayor, Miguel Angel Mancera, says the city will expand public transportation and fund more cycling paths and infrastructure. Mexico City has some of the world’s worst air pollution.

Paris, another city with major air pollution problems, has already taken similar steps with restrictions keeping vehicles registered before 1997 out of the city. It also occasionally closes public roadways with traffic problems for short periods.  

In Barcelona, Spain, another C40 member, making bicycles publicly available reduced carbon dioxide emissions by 9,000 metric tons per year.

Diesel engines were initially encouraged because they produce less carbon dioxide, the greenhouse gas linked by a number of agencies to climate change. However, manufacturers have been unable to cut down the nitrogen oxides and clean up the particulate matter in diesel exhaust.

---

By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

Four major cities plan diesel ban

The mayors of four major international cities have unveiled plans...

Yesterday in <a href="https://www.theguardian.com/commentisfree/2016/dec/01/stephen-hawking-dangerous-time-planet-inequality">The Guardian</a> newspaper Professor Stephen Hawking said we need to work together to tackle the many issues humans have caused our planet. In the article, Hawking spoke out against climate change and threats to employment through AI and robot automation. He believes that we now have technology which could be capable of destroying our planet, and he wishes to warn us of the problems we may soon face.

Professor Hawking deeply believes that we are living in what could potentially be the most dangerous time for the human race. He states that overpopulation, climate change and diseases are only some of the factors threatening us with extinction – the technology we have created to automate our industrial processes should prompt us to “retrain” for a new world where robots can do everyday jobs.

Hawking explained, “For me, the really concerning aspect of this is that now, more than at any time in our history, our species needs to work together. We face awesome environmental challenges: climate change, food production, overpopulation, the decimation of other species, epidemic disease, acidification of the oceans. Together, they are a reminder that we are at the most dangerous moment in the development of humanity.We now have the technology to destroy the planet on which we live, but have not yet developed the ability to escape it. Perhaps in a few hundred years, we will have established human colonies amid the stars, but right now we only have one planet, and we need to work together to protect it.”

The famous physicist has previously spoken of his concerns that robots could wipe out humanity and believes that a mass exodus from Earth is our only chance of survival. Earlier this year he stated, “I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn't go to space.” Speaking on BBC Radio 4 in January 2016 as part of the annual <a href="http://www.bbc.co.uk/programmes/b00729d9">Reith Lecture</a> series, he expressed similar concerns.

In July, Professor Stephen Hawking and <a href="https://www.tesla.com/">Tesla</a> Motors founder Elon Musk led 1,000 robotics experts in an open letter warning that “autonomous weapons will become the Kalashnikovs of tomorrow.”

In 2015, Elon Musk said, “The probable life span of human civilization is much greater if we're a multi-planet species as opposed to a single-planet species. If we're a single planet species, then eventually there will be some extinction event.” Musk hopes to remedy this situation with his company <a href="http://www.spacex.com/">SpaceX</a>, that plans to send humans into space soon.

Earlier in 2016, Professor Hawking said that creating AI “would be the biggest event in human history, unfortunately, it might also be the last.” He does also see the benefits of this technology in the fight against war, disease and poverty, stating, “Looking further ahead, there are no fundamental limits to what can be achieved. There is no physical law precluding particles from being organised in ways that perform even more advanced computations than the arrangements of particles in human brains.”

Professor Stephen Hawking warns us we may destroy earth

Yesterday in The Guardian newspaper Professor Stephen Hawking said we...

According to <a href="http://www.politico.com/story/2016/11/ivanka-trump-climate-czar-232031">Politico</a>, Ivanka Trump is looking for ways to use her new role to combat climate change, despite her father's previous comments that global warming was a “hoax.”

The report goes on to state that Ms. Trump may have an even more public role than the future first lady. The president-elect’s ambitious daughter will take over running the Trump businesses alongside her brothers, but as of yet she has no plans to move to Washington. Politico reported that she may be planning to hire a chief of staff and additional team members.

Trump himself has warmed to the concept that humans may have affected the world’s climate recently, stating in a <a href="http://www.nytimes.com/2016/11/23/us/politics/trump-new-york-times-interview-transcript.html?_r=0">New York Times interview</a> that he thinks there is “some connectivity” between global warming and human activity.

Ivanka and Donald Trump are reported to have an incredibly close relationship, with some commentators believing he may move on climate if pushed by his ambitious daughter. The former fashion model is thought to have more left-leaning views than her father, with an emphasis on women's rights, climate change, family leave and pay equality. Ivanka Trump commented earlier this year, “Policies that allow women with children to thrive should not be novelties – they should be the norm.” In July, she promised her father would change labor laws put in place years before women were a major part of the workforce.

Ivanka Trump makes plans to combat climate change

According to Politico, Ivanka Trump is looking for ways to...

The good news: Oklahoma earthquakes have seen a sharp decline, linked by geologists to new state regulations on wastewater injection. 

The bad news: The state saw more magnitude-5 quakes in 2016 than ever recorded in Oklahoma’s history, and that has scientists worried.

Scientists with the <a href="https://earthquake.usgs.gov/">U.S. Geological Survey</a> and other organizations have been tracking a sharp spike in earthquakes generally along with a rise in earthquake magnitudes in Oklahoma, Kansas and Texas. 

They found that between 1973 and 2008, there were about 21 earthquakes per year above magnitude-3.0 in the central and eastern United States. From 2009 to 2013, that jumped to an average of 99 quakes rating 3.0 or higher. More than 650 magnitude-3.0 or higher tremors were reported in 2014 alone, more than 1,000 logged in 2015, and more than 500 from January to August of this year.

Many of these earthquakes are in Oklahoma, which now logs more quakes per year than California.

The Oklahoma earthquakes appear to be linked to deep injection of wastewater – a byproduct of hydraulic fracturing – into the ground. This practice protects groundwater supplies from the toxic waste produced by fracking, but also places pressure on seismic fault lines, according to scientists. 

These so-called <a href="https://earthquake.usgs.gov/research/induced/">induced earthquakes</a> have the potential to cause major damage to buildings and roadways in Oklahoma, such as the 5.8 shake-up in Pawnee in September, and the 5.0 tremor that hit Cushing in November.

This theory may hold water, as new regulations and limits on wastewater injection appear to have settled some of the Oklahoma earthquakes. 

After Kansas passed new regulations on wastewater injection in 2015, the state saw a dramatic <a href="http://kansaspublicradio.org/kpr-news/kansas-geologists-probe-decrease-kansas-earthquakes">decline in the number of earthquakes</a>. Oklahoma, which was then much less regulated, saw a climb.

Oklahoma followed its northern neighbor’s example this year, setting new regulations in May. Kansas tightened its existing regulations in August. 

Since the new regulations went into effect, Oklahoma has dropped from an average of 2.3 quakes per day at magnitude 3.0 or higher to less than one per day.

However, before fracking became widespread in Oklahoma, the state experienced only one 3.0 earthquake per year, USGS scientists pointed out. One per day is an improvement over the past few years, but still a problem.

Oklahoma has also experienced three quakes magnitude 5.0 or higher this year, including two after the new regulations went into effect, scientists noted. 

The state’s only recorded earthquake higher than 5.0 prior to 2011 was in El Reno, Oklahoma in 1952.

---

By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

Oklahoma earthquakes drop off after new state regs

The good news: Oklahoma earthquakes have seen a sharp decline,...

Tennessee wildfires killed at least four and forced thousands to flee for their lives as the firestorm engulfed the town of Gatlinburg late Tuesday and early Wednesday. 

Tourists also fled the vacation town of Pigeon Forge and Dolly Parton’s Dollywood resort as flames approached, whipped higher by 90 mph winds. 

"I have been watching the terrible fires in the Great Smoky Mountains and I am heartbroken,” Parton said in <a href="http://websterpr.com/news/dolly-parton-statement-east-tennessee-fires">a statement</a> released by her public relations firm. “I am praying for all the families affected by the fire and the firefighters who are working so hard to keep everyone safe.”

As of Wednesday morning, Dollywood and Pigeon Forge had been spared the brunt of the Tennessee wildfires damage. 

Gatlinburg was not so lucky. 

The Tennessee wildfires roared into the town with little warning on Tuesday evening, charring buildings into embers and forcing residents to flee with nothing but the clothes they wore. 

Several of the town’s residents have been reported missing, though an exact number is not available at this time.

<a href="http://www.tennessean.com/">The Tennessean</a> shared <a href="http://knoxne.ws/2gGmOl5">harrowing video</a> from stepbrothers Michael Luciano and Anthony Fulton, who literally fled for their lives as fire blazed on all sides and even in front of them. At one point, they were nearly trapped when a tree fell, but they were eventually able to get through. 

Guests were also trapped for hours in the <a href="http://www.parkvista.com/">Gatlinburg Park Vista</a> hotel as the fire raged around the building, but firefighters were able to keep them safe until they could be evacuated early Wednesday morning.

Meteorologists at Accuweather.com, a private forecasting firm, were expecting a thunderstorm to bring rain to the area on Wednesday evening. However, it could also bring more high winds and lightning, upping fire risk.

It may be the last rain in the region for a while, said Dr. Luigi Romolo, regional climatologist at the <a href="http://www.srcc.lsu.edu/">Southern Regional Climate Center</a> based at Louisiana State University.

“Across the South, there is no real trend in the forecast for precipitation over the next few months,” he said. That means a few more months of a drought that has created ideal conditions for the spread of wildfires.

The fires in the Great Smoky Mountains have been burning for weeks. As of November 30, they had burned more than 149,000 acres across eight states, according to the <a href="http://www.nwcg.gov/">National Wildfire Coordinating Group’s</a> incident reporting system.

“Drought is actually a regular occurrence of climate,” Romolo said. However, drought combined with warmer than usual temperatures, which the south has been experiencing since late summer, can create extremely dry conditions that provide fuel for fires.

“Warmer temperatures create a greater demand for water from the ground. If it’s not raining, you’re not replenishing that water, and over time, plants and shrubs are going to suffer,” Romolo said.

Severe drought has plagued the areas worst-affected by the fires for months, according to the <a href="http://droughtmonitor.unl.edu/">United States Drought Monitor</a>: eastern Tennessee, western North Carolina and South Carolina, and northern Georgia and Alabama. Fires are also burning in Kentucky, Virginia and West Virginia. 

Still, it’s too soon to tell whether the drought and Tennessee wildfires are part of any wider pattern of climate change. Drought does happen naturally without any outside forces, Romolo pointed out, just as unusual amounts of rainfall can. 

Investigators believe most of the fires burning throughout the South, including the one that roared through Gatlinburg, are “human-caused,” though that can mean anything from an improperly quenched campfire or cigarette tossed out of a vehicle to intentional arson.

The Tennessee Bureau of Investigation has launched a hotline for residents who were separated from their loved ones during the escape or who cannot get ahold of family and friends in the area: 1-800-TBI-FIND (1-800-824-3463).

The East Tennessee chapter of the <a href="http://www.redcross.org/local/tennessee/local-chapters/east-tennessee">American Red Cross</a> and the <a href="http://www.cfmt.org">Community Foundation of Middle Tennessee</a> are working to help the residents and towns affected by the fires.

---

By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

Tennessee wildfires burn Gatlinburg, threaten Dollywood

Tennessee wildfires killed at least four and forced thousands to...

Alaska has a new mystery that has some scientists stumped: disappearing caribou.

A massive herd of caribou that roams the Arctic region in the state has dwindled, with its population declining by more than half in just six years.

In 2010, the herd hit a peak population of about 70,000 caribou. By 2013, numbers had dwindled to about 50,000, and this year, <a href="http://www.adfg.alaska.gov/">Alaska Department of Fish and Game</a> surveys suggest the herd’s size has dropped to around 22,000.

Researchers can’t settle on a reason. They’ve ruled out hunting by wolves and bears as a factor, and while pregnancy levels are down among female caribou, it’s not enough to account for the population bleed.

Biologists can find so sign of diseases among the herd. They have seen a higher than normal death rate among the female caribou fitted with radio tracking collars, but no sign of what is causing those deaths, they said.

One change that may have played a role in 2013 was a later than normal spring. That seems to have led to poor nutrition among the caribou that year, scientists said. Researchers plan to study satellite and weather tracking data to see if other unusual weather patterns might have affected the mushrooms, lichen, sedges, and other plants the caribou eat, leading to malnutrition. 

Some of the herd may have split off to join other groups of caribou, but the scientists aren’t sure of the potential extent, or whether it would have caused such a sharp drop in numbers. Because not many of the adult caribou are fitted with the tracking collars, it’s difficult to account for all of the herd’s movements, they said.

The scientists declined to blame climate change for the herd’s population decline until they had studied more data. 

However, environmental groups believe that Alaskan polar bears have been affected by global warming in recent years. 

The advocacy group <a href="http://www.polarbearsinternational.org/">Polar Bears International</a> notes that loss of polar bear habitat due to sea ice melt has been linked to reduced size and weight among the bears, as well as a lower survival rate among cubs. 

The <a href="https://www.usgs.gov/">U.S. Geological Survey</a> is also working to determine what might be affecting the caribou. If summers have gotten warmer in the areas where they typically feed, booming insect populations could be driving them away, the agency’s wildlife biologists speculate.

However, studies comparing the caribous’ range to the 1970s have so far found no significant changes. 

Alaska residents have also questioned whether lax hunting rules for out-of-state visitors have played a role. The state fish and game department plans to reduce the number of caribou that can be killed from the herd this hunting season.

Two other north Alaskan caribou herds have seen declining numbers in recent years, although one seems to have stabilized, the department said.

Alaska biologists investigate mystery of disappearing caribou

Alaska has a new mystery that has some scientists stumped:...

With the holiday season upon us, it’s easy to let our daily routines slip a little. If haven’t had a chance to check out <a href="http://www.earth.com/">Earth.com</a> and <a href="http://www.greenatom.earth/">GreenAtom.earth</a> over the past few days, here are five top stories you should be sure not to miss:
<ol>
 	<li><a href="http://www.earth.com/news/cereal-cropping/">Scientists identify most environmentally friendly cereal cropping process</a>: A research team from Denmark found that how grain crops are grown and harvested can have an effect on the environment, and identified the methods and crops that cause less damage.</li>
</ol>
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 	<li><a href="http://www.earth.com/news/soil-science-helps-boost-agriculture/">Soil science helps boost agricultural success</a>: Two scientists have developed a set of equations that will help farmers, land managers and others determine what a patch of soil can best be used for.</li>
</ol>
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 	<li><a href="http://www.earth.com/news/saltmarsh-sparrow-may-go-exctinct/">Saltmarsh sparrow may be extinct within 50 years</a>: The at-risk species could be the first bird species to go extinct in the continental United States since 1931. </li>
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 	<li><a href="http://www.greenatom.earth/news/phytoplankton-a-new-sustainable-food-and-fuel-source/">Scientists see phytoplankton as a new sustainable food and fuel source</a>: Lipids from the microscopic marine plant can be removed and used for fuel. The leftovers from this process are a highly nutritious biomass, scientists said.</li>
</ol>
<ol start="5">
 	<li><a href="http://www.earth.com/news/australasian-marsupials-climate-change/">Australasian marsupials survived ancient climate change</a>: As the climate became drier and rainforests dried out five to 10 million years ago, Australian marsupials survived the shift by adapting to the new grasslands, scientists said.</li>
</ol>
---

By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

This week's top stories from Earth.com

With the holiday season upon us, it’s easy to let...

Every year, thousands of people die in earthquakes around the world. However, new research shows that small gravity shifts could offer valuable minutes for people to flee to safety in areas that are about to shake, rattle and roll.

When an earthquake is triggered, a few changes take place before the shaking is actually felt. Among them are tiny shifts in the Earth’s gravitational field, said Professor Jean-Paul Montagner, a seismologist with the <a href="http://www.ipgp.fr/en">Institut de Physique du Globe de Paris</a>. 

In fact, the gravity shifts may come minutes before seismic waves can be detected by instrumentation – the current earthquake warning system. By the time seismic waves are felt, the earthquake has already begun, but gravitational shifts can be detected at the speed of light, the <a href="http://www.nature.com/articles/ncomms13349">new research found</a>. 

Montagner believes that a network of instrumentation that can pick up gravitational shifts might offer a better early warning system.

The extra seconds or even minutes could save thousands of lives, Montagner and his research team said.

The team first began to look at how earthquakes affect gravity in the wake of the massive Tohoku earthquake that struck Japan on March 11, 2011. The six-minute, 9.0-magnitude quake triggered a tsunami and a major nuclear disaster. 

The official death toll for that disaster stands at 15,894, with more than 2,500 still missing. Thousands more were injured, and hundreds of thousands were left homeless.

Previous research showed that the Tohoku quake left scars on the Earth’s gravitational field that still persist. Montagner’s team wondered whether there may have been signs in the Earth’s gravity before the tremors began that a quake was coming.

The researchers found tiny gravitational signals just before the quake began. The signals could be detected far from the quake’s epicenter. 

While the scientists can’t yet pinpoint where an earthquake is going to happen, further research and a more extensive sensor network could provide a warning when a massive earthquake or series of several earthquakes are about to occur, the researchers said.

Their findings were published in the journal <a href="http://www.nature.com/ncomms/">Nature Communications</a>.

---

By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

Gravity shifts could offer earthquake early warning system

Every year, thousands of people die in earthquakes around the...

Some innovators are finding animal inspiration – not from nature, but from one of the world’s most popular pets. It turns out that studying cat tongues has offered up an array of ideas that could be useful in robotics, medicine, and the beauty industry.

Researchers based at <a href="http://www.gatech.edu/">Georgia Tech</a> used macro and high-speed videography to record cats as they groomed, then used the imaging to print three-dimensional models at a 400 percent scale. 

The project revealed that the sandpaper-like feel of a cat’s tongue is due to hook-like features that are the shape and sharpness of tiny claws. These little hooks make cat tongues ideal for detangling their fur. The flexibility of the tongue and the spines themselves help with this task.

And that gave the researchers some ideas. The most obvious, of course, is that hairbrushes modeled after cat tongues instead of with stiff, straight bristles might make detangling hair easier – and be easier to clean. 

The hooked shape of the spines on cats’ tongues make them “self-cleaning,” with caught fur sliding off easily. A similarly shaped brush could be cleaned by simply sliding a hand from the tip to the end.

However, the research could also offer up improved grips for soft robotics systems, as well as innovations in wound cleaning.

In robotics, engineers have struggled to create soft materials that can grip surfaces. The cat’s soft, flexible tongue could offer a model for a solution. 

The scientists aren’t done studying cats. They’ve examined the tongues of domestic cats, but would like to also study large cats like lions and tigers so they can compare the structures of their tongues. They’re hoping to find out how the spacing of the spines affects resistance. 

The researchers presented their findings at the 69th annual meeting of the <a href="https://www.aps.org/units/dfd/">American Physical Society’s Division of Fluid Dynamics</a>. They’re planning to create mimic technology based on their findings.

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By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

Cat tongues inspire ideas for new innovations

Some innovators are finding animal inspiration – not from nature,...

As Americans celebrate Thanksgiving this year, it’s time to put aside our worries for a day and remember that we have a lot to be grateful for – including these five incredible scientific breakthroughs that taught us more about the planet we all live on. Happy Thanksgiving:
<ol>
 	<li><a href="http://www.earth.com/video/images-photosynthesis-action/">Scientists capture images of photosynthesis in action</a>: Humans have known about photosynthesis – the process through which plants use light, air and the nutrients absorbed from the soil to create their own food – for a while. We don’t really understand how it works, though. Now, scientists are using ultrafast X-ray lasers to get a better picture of the process, and their results could lead to cleaner, more plentiful fuel sources.</li>
</ol>
<ol start="2">
 	<li> Researchers investigate alternative sources of fuel: Scientists at the Department of Energy’s Pacific Northwest National Laboratory may have discovered a way to <a href="http://www.earth.com/video/scientists-sewage-future-biofuel/">turn sewage into biofuel</a> using a process called hydrothermal liquefaction. Meanwhile, researchers at Tel Aviv University believe they’ve figured out how <a href="http://www.earth.com/news/algae-may-soon-be-a-source-of-clean-energy/">microalgae produces hydrogen</a>, the first step in increasing its output of this clean fuel source.</li>
</ol>
<ol start="3">
 	<li><a href="http://www.earth.com/news/asteroid-impacts-responsible-life-earth/">Asteroid impacts may be responsible for seeding life on Earth</a>: A group of researchers studying the effects of an asteroid suspected wiping out the dinosaurs 66 million years ago made a surprising discovery. The asteroid impact caused some changes in surrounding rock that might explain how much earlier asteroids created conditions for life to take hold on Earth.</li>
</ol>
<ol start="4">
 	<li><a href="http://www.earth.com/news/human-occupation-actually-improves-some-environments/">Human occupation actually improves some environments</a>: While scientists normally seek to minimize the human impact on the environment, from litter to greenhouse gas emissions, some ecosystems have actually benefited from human residents. One of these is the temperate rainforest along the coast of British Columbia, which benefited from First Nations people living there.</li>
</ol>
<ol start="5">
 	<li><a href="http://www.earth.com/news/study-eco-friendly-wines-taste-better/">Study: Eco-friendly wines taste better</a>: A study at the University of California, Los Angeles, found that wines grown by “eco-friendly” vintners got better reviews from wine experts in blind taste-tests. They’re also often cheaper to produce, the study found.</li>
</ol>
---

By <a href="mailto:oliviagharvey24@gmail.com">Olivia Harvey</a>, <a href="http://earth.com">Earth.com</a> Staff Writer

5 Earth stories we were grateful for in 2016

As Americans celebrate Thanksgiving this year, it’s time to put...

Scientists can now get a very close look at how plants make oxygen using water molecules, thanks to an international team of researchers.

Led by Dr. Johannes Messinger from <a href="http://www.umu.se/english">Umea University</a> in Sweden, the scientists used experimental molecular studies to produce high-resolution images of photosystem II, a protein complex in the light-dependent reactions of the process of photosynthesis.

The images will allow researchers to take a close look at the step-by-step conversion of two water molecules into one oxygen molecule that takes place during this part of photosynthesis, Messinger said.

Plants play a large role in mitigating the effects of climate change, according to the researchers. In addition to absorbing atmospheric carbon from the greenhouse gas carbon dioxide, plants also convert water molecules into oxygen and hydrogen.

If humans can learn how plants split water molecules, they can do the same, providing more oxygen in the atmosphere and hydrogen as a cleaner source of energy than carbon-based fuels, Messinger said.

The visualization of the plants’ process was created with the help of the X-ray free electron laser at Stanford University’s <a href="https://www6.slac.stanford.edu/">SLAC National Accelerator Laboratory</a>.

The team grew microcrystals of the photosystem II protein, then placed them on a conveyor belt. The laser was used to stimulate the crystals similar to sunlight and jumpstart the water splitting process. 

The crystals were then hit with superfast X-ray pulses to visualize them. The study describes how the scientists were able to use the data gathered during this experiment to produce high-resolution images showing the structural differences in the photosystem II protein at different stages of the water splitting process.

Messinger has since joined the Molecular Biometrics Programme at <a href="https://www.uu.se/en/">Uppsala University</a>.

—

Researchers on verge of solving how plants make oxygen

Scientists can now get a very close look at how...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Flu viruses are more flexible than expected

[sendtonews key="G9bUoxcjr4-2511624-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Detecting mercury contamination with the tap of a finger

[sendtonews key="LvS8v8bp9z-2564889-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

How does salt makes things taste better?

[sendtonews key="X0f6OHYoI4-2310561-12187" type="single"] Today’s Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Santiago, Chile in South America

[sendtonews key="JRaP49ISmm-2357509-12187" type="single"] Today’s Video of the Day from the...

Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Interactive map of the universe includes 200,000 galaxies

[sendtonews key="e4ZG0Jawp3-2374785-12187" type="single"] Astronomers at Johns Hopkins University have created...

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

[sendtonews key="6HyfrAJTBI-1831843-12187" type="single"] Today’s Video of the Day from the...

Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites capture the world's biggest and fastest waves

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

[sendtonews key="761m2QQvR1-2035772-12187" type="single"] Today’s Video of the Day from the...