Study finds microplastics in Florida birds of prey for 1st time

Big bird with strong-looking legs and hooked beak sitting on a branch.

Ospreys, like the one pictured here, are among the types of birds of prey in Florida that have been found to be accumulating microplastics in their stomachs. Image via Linda Walters/ University of Central Florida.

A new study has found, for the first time, the presence of microplastics in the digestive systems of terrestrial and aquatic birds of prey in Florida, including hawks, ospreys and owls.

Microplastics are not a specific kind of plastic, but rather any type of plastic fragment that is less than 5 mm in length – less than the size of a pencil tip. They enter natural ecosystems from a variety of sources, including cosmetics, synthetic clothing, and industrial processes.

The accumulation of microplastics in birds’ digestive systems could lead to poisoning, starvation and death, according to the study, which was published online in the journal Environmental Pollution. University of Central Florida biologist Julia Carlin is the study’s lead author, said that birds of prey are critical to a functioning ecosystem:

Birds of prey are top predators in the ecosystem and by changing the population or health status of the top predator, it completely alters all of the animals, organisms and habitats below them on the food web.

Past studies have documented increasing amounts of microplastics in the guts of fish, marine birds, and filter-feeding invertebrates, such as oysters. There have also been recent reports of whales dying from eating dozens of pounds of plastic, including plastic bags. However, birds of prey have not been thoroughly examined before, partly due to their protected status. The researchers for the new study were able to overcome this by working with the Audubon Center for Birds of Prey in Maitland, Florida, a rehabilitation center that helps injured raptors.

With the center’s permits, the researchers were able to examine the stomach contents of 63 birds that were dead when they arrived at the center or died 24 hours after they arrived. Using dissecting microscopes and spectroscopy, the researchers found microplastics in the digestive systems of all birds examined.

The most common types of microplastic in the birds were microfibers, which accounted for 86% of the plastics found. Microfibers can come from synthetic ropes or clothing and may end up in ecosystems through wastewater from clothes-washing machines.

Study co-author Linda Walters, of University of Central Florida, suggested some solutions to the problem could be removing plastic from open landfills, carefully discarding plastic trash, buying natural fabrics instead of plastic-based ones, and retrofitting water treatment plants and stormwater drains to capture microplastics. Walters said:

We have all benefitted from the convenience of plastics, but plastics do not go away once produced.

Bottom line: A new study has found microplastics in birds of prey – including hawks, ospreys and owls – in Florida for the first time.

Source: Microplastic accumulation in the gastrointestinal tracts in birds of prey in central Florida, USA

Via University of Central Florida



from EarthSky https://ift.tt/2TuFvhq
Big bird with strong-looking legs and hooked beak sitting on a branch.

Ospreys, like the one pictured here, are among the types of birds of prey in Florida that have been found to be accumulating microplastics in their stomachs. Image via Linda Walters/ University of Central Florida.

A new study has found, for the first time, the presence of microplastics in the digestive systems of terrestrial and aquatic birds of prey in Florida, including hawks, ospreys and owls.

Microplastics are not a specific kind of plastic, but rather any type of plastic fragment that is less than 5 mm in length – less than the size of a pencil tip. They enter natural ecosystems from a variety of sources, including cosmetics, synthetic clothing, and industrial processes.

The accumulation of microplastics in birds’ digestive systems could lead to poisoning, starvation and death, according to the study, which was published online in the journal Environmental Pollution. University of Central Florida biologist Julia Carlin is the study’s lead author, said that birds of prey are critical to a functioning ecosystem:

Birds of prey are top predators in the ecosystem and by changing the population or health status of the top predator, it completely alters all of the animals, organisms and habitats below them on the food web.

Past studies have documented increasing amounts of microplastics in the guts of fish, marine birds, and filter-feeding invertebrates, such as oysters. There have also been recent reports of whales dying from eating dozens of pounds of plastic, including plastic bags. However, birds of prey have not been thoroughly examined before, partly due to their protected status. The researchers for the new study were able to overcome this by working with the Audubon Center for Birds of Prey in Maitland, Florida, a rehabilitation center that helps injured raptors.

With the center’s permits, the researchers were able to examine the stomach contents of 63 birds that were dead when they arrived at the center or died 24 hours after they arrived. Using dissecting microscopes and spectroscopy, the researchers found microplastics in the digestive systems of all birds examined.

The most common types of microplastic in the birds were microfibers, which accounted for 86% of the plastics found. Microfibers can come from synthetic ropes or clothing and may end up in ecosystems through wastewater from clothes-washing machines.

Study co-author Linda Walters, of University of Central Florida, suggested some solutions to the problem could be removing plastic from open landfills, carefully discarding plastic trash, buying natural fabrics instead of plastic-based ones, and retrofitting water treatment plants and stormwater drains to capture microplastics. Walters said:

We have all benefitted from the convenience of plastics, but plastics do not go away once produced.

Bottom line: A new study has found microplastics in birds of prey – including hawks, ospreys and owls – in Florida for the first time.

Source: Microplastic accumulation in the gastrointestinal tracts in birds of prey in central Florida, USA

Via University of Central Florida



from EarthSky https://ift.tt/2TuFvhq

Have you seen Venus and Mercury? Photos here

See an amazing collection of Venus and Mercury photos at EarthSky Community Photos.

Venus and Mercury will be near the moon this weekend. Charts and info here.

Venus and Mercury over New York City.

View at EarthSky Community Photos. | Alexander Krivenyshev of the website WorldTimeZone.com caught Venus and Mercury on one of the evenings when they were closest – May 21, 2020 – shining over New York City. Alexander was in North Bergen, New Jersey when he captured this image. Thanks, Alexander!

Venus and Mercury in a red twilight sky, reflecting in a lake.

View at EarthSky Community Photos. | Mike Shaw captured this beautiful image on May 20. He wrote: “The Mercury – Venus conjunction of 2020 is seen here setting over a peaceful lake in the Carlos Avery Wildlife Refuge in central Minnesota. If only the sounds of the frogs and songbirds could be included! Reflections of both planets are visible in the still lake surface, a good indicator of the serenity of the evening. This image was made under the provisions of a Special Use permit to access the normally closed wildlife refuge at night.” Mike has a wider view of this same scene, here. Thank you, Mike!

Chart showing the moon, Venus, Mercury on May 23-25, 2020.

The young moon will sweep past Venus and Mercury on May 23, 24 and 25, 2020. Read more.

Bright Venus, with Mercury to its lower left, in a twilight sky.

View at EarthSky Community Photos. | Helio C. Vital in Rio de Janeiro, Brazil, captured Venus and Mercury on May 20, when they were about 3 degrees apart. As viewed from the Southern Hemisphere, Mercury was seen to the lower left of Venus that night. These objects are moving rapidly on the sky’s dome with respect to each other. Your perspective on them also shifts as seen from various parts of the globe. Try Stellarium-Web for a precise view from your location. Thank you, Helio!

Sky fading from blue to orange at horizon with two white dots.

View larger at EarthSky Community Photos. | Ken Ferrere caught Venus and Mercury in the sunset sky over Groton, Massachusetts, on May 20, 2020. Thank you, Ken!

Very bright Venus in a twilight sky, and Mercury below Venus.

View at EarthSky Community Photos. | Jenney Disimon in Sabah, N. Borneo, caught Venus and Mercury on May 19, 2020. Thank you, Jenney!

Mosaic showing Venus and Mercury setting.

View larger at EarthSky Community Photos. | Peter Lowenstein in the Southern Hemisphere (Mutare, Zimbabwe) made a successful attempt to photograph Venus and Mercury setting after sunset on Monday, May 18, 2020. In the larger version of this mosaic, you can see both planets. Venus is bright, and above the crest of the hill. Mercury is fainter and lower in the sky, above the lower ridgeline of the hill, in the bottom middle of the photo. You can see that Mercury comes close to setting behind the hill as the mosaic progresses from upper left to bottom right (as time passes after sunset). Thank you, Peter!

Bottom line: Photos from the EarthSky Community of the planets Venus and Mercury. These worlds are closest on our sky’s dome for all of 2020 around May 21 and 22.

See an amazing collection of Venus and Mercury photos at EarthSky Community Photos.

Venus and Mercury will be near the moon this weekend. Charts and info here.



from EarthSky https://ift.tt/3bW6fOl

See an amazing collection of Venus and Mercury photos at EarthSky Community Photos.

Venus and Mercury will be near the moon this weekend. Charts and info here.

Venus and Mercury over New York City.

View at EarthSky Community Photos. | Alexander Krivenyshev of the website WorldTimeZone.com caught Venus and Mercury on one of the evenings when they were closest – May 21, 2020 – shining over New York City. Alexander was in North Bergen, New Jersey when he captured this image. Thanks, Alexander!

Venus and Mercury in a red twilight sky, reflecting in a lake.

View at EarthSky Community Photos. | Mike Shaw captured this beautiful image on May 20. He wrote: “The Mercury – Venus conjunction of 2020 is seen here setting over a peaceful lake in the Carlos Avery Wildlife Refuge in central Minnesota. If only the sounds of the frogs and songbirds could be included! Reflections of both planets are visible in the still lake surface, a good indicator of the serenity of the evening. This image was made under the provisions of a Special Use permit to access the normally closed wildlife refuge at night.” Mike has a wider view of this same scene, here. Thank you, Mike!

Chart showing the moon, Venus, Mercury on May 23-25, 2020.

The young moon will sweep past Venus and Mercury on May 23, 24 and 25, 2020. Read more.

Bright Venus, with Mercury to its lower left, in a twilight sky.

View at EarthSky Community Photos. | Helio C. Vital in Rio de Janeiro, Brazil, captured Venus and Mercury on May 20, when they were about 3 degrees apart. As viewed from the Southern Hemisphere, Mercury was seen to the lower left of Venus that night. These objects are moving rapidly on the sky’s dome with respect to each other. Your perspective on them also shifts as seen from various parts of the globe. Try Stellarium-Web for a precise view from your location. Thank you, Helio!

Sky fading from blue to orange at horizon with two white dots.

View larger at EarthSky Community Photos. | Ken Ferrere caught Venus and Mercury in the sunset sky over Groton, Massachusetts, on May 20, 2020. Thank you, Ken!

Very bright Venus in a twilight sky, and Mercury below Venus.

View at EarthSky Community Photos. | Jenney Disimon in Sabah, N. Borneo, caught Venus and Mercury on May 19, 2020. Thank you, Jenney!

Mosaic showing Venus and Mercury setting.

View larger at EarthSky Community Photos. | Peter Lowenstein in the Southern Hemisphere (Mutare, Zimbabwe) made a successful attempt to photograph Venus and Mercury setting after sunset on Monday, May 18, 2020. In the larger version of this mosaic, you can see both planets. Venus is bright, and above the crest of the hill. Mercury is fainter and lower in the sky, above the lower ridgeline of the hill, in the bottom middle of the photo. You can see that Mercury comes close to setting behind the hill as the mosaic progresses from upper left to bottom right (as time passes after sunset). Thank you, Peter!

Bottom line: Photos from the EarthSky Community of the planets Venus and Mercury. These worlds are closest on our sky’s dome for all of 2020 around May 21 and 22.

See an amazing collection of Venus and Mercury photos at EarthSky Community Photos.

Venus and Mercury will be near the moon this weekend. Charts and info here.



from EarthSky https://ift.tt/3bW6fOl

Scientists identify chemicals in noxious weed that 'disarm' deadly bacteria

"Nature is the best chemist, hands down," says Emory ethnobotanist Cassandra Quave, shown with berries from the Brazilian peppertree. The plant is native to South America where traditional healers in the Amazon have used it as a treatment for skin infections. 

By Carol Clark

Scientists have identified specific compounds from the Brazilian peppertree — a weedy, invasive shrub in Florida — that reduce the virulence of antibiotic-resistant staph bacteria. Scientific Reports published the research, demonstrating that triterpenoid acids in the red berries of the plant “disarm” dangerous staph bacteria by blocking its ability to produce toxins.

The work was led by the lab of Cassandra Quave, an assistant professor in Emory University’s Center for the Study of Human Health and the Emory School of Medicine’s Department of Dermatology. The researchers’ laboratory experiments provide the first evidence that triterpenoid acids pack a punch against methicillin-resistant Staphylococcus aureus, known as MRSA.

The Brazilian peppertree (Schinus terebinthifolia), native to South America, is also abundant in Florida, where it forms dense thickets that crowd out native species. “It is a noxious weed that many people in Florida hate, for good reason,” Quave says. “But, at the same time, there is this rich lore about the Brazilian Peppertree in the Amazon, where traditional healers have used the plant for centuries to treat skin and soft tissue infections.”

Brazilian peppertree
Quave, a leader in the field of medical ethnobotany and a member of the Emory Antibiotic Resistance Center, studies how indigenous people incorporate plants in healing practices to uncover promising candidates for new drugs.

The Centers for Disease Control and Prevention calls antibiotic resistance “one of the biggest public health challenges of our time.” Each year in the U.S., at least 2.8 million people get antibiotic-resistant infections, leading to more than 35,000 deaths.

“Even in the midst of the current viral pandemic of COVID-19, we can’t forget about the issue of antibiotic resistance,” Quave says. She notes that many COVID-19 patients are receiving antibiotics to deal with secondary infections brought on by their weakened conditions, raising concerns about a later surge in antibiotic-resistant infections.

In 2017, the Quave lab published the finding that a refined, flavone-rich mix of 27 compounds extracted from the berries of the Brazilian peppertree inhibits formation of skin lesions in mice infected with MRSA. The extract works not by killing the MRSA bacteria, but by repressing a gene that allows the bacteria cells to communicate with one another. Blocking that communication prevents the cells from taking collective action, which essentially disarms the bacteria by preventing it from excreting the toxins it uses to damage tissues. The body’s immune system then stands a better chance of healing a wound.

That approach is different from the typical treatment of blasting deadly bacteria with drugs designed to kill them, which can help fuel the problem of antibiotic resistance. Some of the stronger bacteria may survive these drug onslaughts and proliferate, passing on their genes to offspring and leading to the evolution of deadly “super bugs.”

For the current paper, the researchers wanted to narrow down the scope of 27 major compounds from the berries to isolate the specific chemicals involved in disarming MRSA. They painstakingly refined the original compounds, testing each new iteration for its potency on the bacteria. They also used a series of analytical chemistry techniques, including mass spectrometry, nuclear magnetic resonance spectroscopy and X-ray crystallography to gain a clear picture of the chemicals involved in the anti-virulence mechanism.

The results showed that three triterpenoid acids worked equally well at inhibiting MRSA from forming toxins in a petri dish, without harming human skin cells. And one of the triterpenoid acids worked particularly well at inhibiting the ability of MRSA to form lesions on the skin of mice. The researchers also demonstrated that the triterpenoid acids repressed not just one gene that MRSA uses to excrete toxins, but two genes involved in that process.

“Nature is the best chemist, hands down,” Quave says. She adds that weeds, in particular, tend to have interesting chemical arsenals that they may use to protect them from diseases so they can more easily spread in new environments.

The research team plans to do further studies to test the triterpenoid acids as treatments for MRSA infections in animal models. If those studies are promising, the next step would be to work with medicinal chemists to optimize the compounds for efficacy, delivery and safety before testing on humans.

“Plants are so incredibly complex chemically that identifying and isolating particular extracts is like picking needles out of haystacks,” Quave says. “When you’re able to pluck out molecules with medicinal properties from these complex natural mixtures, that’s a big step forward to understanding how some traditional medicines may work, and for advancing science towards a potential drug development pathway.”

First authors of the current paper are Huaqiao Tang — a former visiting scholar at Emory and a veterinarian at Sichuan Agricultural University in China — and Gina Porras, an Emory post-doctoral fellow. In addition to senior author Quave, co-authors include Francois Chassagne and James Lyles, who are both members of the Quave lab; John Basca, director of Emory’s X-ray Crystallography Center; and Alexander Horswill and Morgan Brown from the University of Colorado School of Medicine.

Related:
Brazilian peppertree packs power to knock out antibiotic-resistant bacteria
Chestnut leaves yield extract that disarms deadly bacteria
A future without antibiotics?

from eScienceCommons https://ift.tt/2WORngu
"Nature is the best chemist, hands down," says Emory ethnobotanist Cassandra Quave, shown with berries from the Brazilian peppertree. The plant is native to South America where traditional healers in the Amazon have used it as a treatment for skin infections. 

By Carol Clark

Scientists have identified specific compounds from the Brazilian peppertree — a weedy, invasive shrub in Florida — that reduce the virulence of antibiotic-resistant staph bacteria. Scientific Reports published the research, demonstrating that triterpenoid acids in the red berries of the plant “disarm” dangerous staph bacteria by blocking its ability to produce toxins.

The work was led by the lab of Cassandra Quave, an assistant professor in Emory University’s Center for the Study of Human Health and the Emory School of Medicine’s Department of Dermatology. The researchers’ laboratory experiments provide the first evidence that triterpenoid acids pack a punch against methicillin-resistant Staphylococcus aureus, known as MRSA.

The Brazilian peppertree (Schinus terebinthifolia), native to South America, is also abundant in Florida, where it forms dense thickets that crowd out native species. “It is a noxious weed that many people in Florida hate, for good reason,” Quave says. “But, at the same time, there is this rich lore about the Brazilian Peppertree in the Amazon, where traditional healers have used the plant for centuries to treat skin and soft tissue infections.”

Brazilian peppertree
Quave, a leader in the field of medical ethnobotany and a member of the Emory Antibiotic Resistance Center, studies how indigenous people incorporate plants in healing practices to uncover promising candidates for new drugs.

The Centers for Disease Control and Prevention calls antibiotic resistance “one of the biggest public health challenges of our time.” Each year in the U.S., at least 2.8 million people get antibiotic-resistant infections, leading to more than 35,000 deaths.

“Even in the midst of the current viral pandemic of COVID-19, we can’t forget about the issue of antibiotic resistance,” Quave says. She notes that many COVID-19 patients are receiving antibiotics to deal with secondary infections brought on by their weakened conditions, raising concerns about a later surge in antibiotic-resistant infections.

In 2017, the Quave lab published the finding that a refined, flavone-rich mix of 27 compounds extracted from the berries of the Brazilian peppertree inhibits formation of skin lesions in mice infected with MRSA. The extract works not by killing the MRSA bacteria, but by repressing a gene that allows the bacteria cells to communicate with one another. Blocking that communication prevents the cells from taking collective action, which essentially disarms the bacteria by preventing it from excreting the toxins it uses to damage tissues. The body’s immune system then stands a better chance of healing a wound.

That approach is different from the typical treatment of blasting deadly bacteria with drugs designed to kill them, which can help fuel the problem of antibiotic resistance. Some of the stronger bacteria may survive these drug onslaughts and proliferate, passing on their genes to offspring and leading to the evolution of deadly “super bugs.”

For the current paper, the researchers wanted to narrow down the scope of 27 major compounds from the berries to isolate the specific chemicals involved in disarming MRSA. They painstakingly refined the original compounds, testing each new iteration for its potency on the bacteria. They also used a series of analytical chemistry techniques, including mass spectrometry, nuclear magnetic resonance spectroscopy and X-ray crystallography to gain a clear picture of the chemicals involved in the anti-virulence mechanism.

The results showed that three triterpenoid acids worked equally well at inhibiting MRSA from forming toxins in a petri dish, without harming human skin cells. And one of the triterpenoid acids worked particularly well at inhibiting the ability of MRSA to form lesions on the skin of mice. The researchers also demonstrated that the triterpenoid acids repressed not just one gene that MRSA uses to excrete toxins, but two genes involved in that process.

“Nature is the best chemist, hands down,” Quave says. She adds that weeds, in particular, tend to have interesting chemical arsenals that they may use to protect them from diseases so they can more easily spread in new environments.

The research team plans to do further studies to test the triterpenoid acids as treatments for MRSA infections in animal models. If those studies are promising, the next step would be to work with medicinal chemists to optimize the compounds for efficacy, delivery and safety before testing on humans.

“Plants are so incredibly complex chemically that identifying and isolating particular extracts is like picking needles out of haystacks,” Quave says. “When you’re able to pluck out molecules with medicinal properties from these complex natural mixtures, that’s a big step forward to understanding how some traditional medicines may work, and for advancing science towards a potential drug development pathway.”

First authors of the current paper are Huaqiao Tang — a former visiting scholar at Emory and a veterinarian at Sichuan Agricultural University in China — and Gina Porras, an Emory post-doctoral fellow. In addition to senior author Quave, co-authors include Francois Chassagne and James Lyles, who are both members of the Quave lab; John Basca, director of Emory’s X-ray Crystallography Center; and Alexander Horswill and Morgan Brown from the University of Colorado School of Medicine.

Related:
Brazilian peppertree packs power to knock out antibiotic-resistant bacteria
Chestnut leaves yield extract that disarms deadly bacteria
A future without antibiotics?

from eScienceCommons https://ift.tt/2WORngu

One of Jupiter’s Trojan asteroids has a comet-like tail

Diagam showing the inner solar system, asteroid belt and Jupiter and its orbit, with locations of Trojan asteroids indicated.

Astronomers use the name Trojan asteroid for all the asteroids collected at Jupiter’s 2 stable Lagrange points, 60 degrees ahead of the planet in its orbit and 60 degrees behind. They further divide them into 2 camps with the Greek camp orbiting in front of Jupiter, and the Trojan camp trailing behind. The newly discovered Trojan with a comet-tail is orbiting ahead of Jupiter. Image via Wikimedia Commons.

Scientific language is like a net thrown over nature. Scientists try to name and categorize natural objects, and usually that process goes smoothly … but sometimes it doesn’t, as in 2006 when Pluto was demoted from major planet to dwarf planet. Pluto didn’t change. Our understanding of Pluto’s context in our solar system had evolved. Asteroids and comets also sometimes defy easy categorization. There’s 3200 Phaethon, for example, which has an asteroid name, but which is the parent body for December’s Geminid meteor shower; if you follow meteor showers, you know they stem from comets. Astronomers are discovering more and more objects that start out looking like asteroids, and later develop activity, such as comet-like tails. Today (May 21, 2020), the Institute for Astronomy at the University of Hawai’i announced a new asteroid-with-a-comet-tail in a very interesting place in our solar system. This object is moving along the orbit traveled by Jupiter around our sun. It’s thus considered a Trojan asteroid, the first Trojan asteroid known with a comet-like tail. The University of Hawai’i explained:

Trojan asteroids follow the same orbit as a planet, but stay either around 60 degrees ahead or 60 degrees behind along the orbit. Earth has at least one Trojan asteroid, and Neptune has dozens. Jupiter has hundreds of thousands. The Jupiter Trojan asteroids orbit the sun in two huge swarms, one swarm orbiting ahead of the planet (where 2019 LD2 was found) and one swarm orbiting behind it. The Trojan asteroids have been captured into these orbits by Jupiter’s strong gravity.

The discovery comes from the Asteroid Terrestrial-impact Last Alert System (ATLAS), a NASA-funded project that uses wide-field telescopes to scan for asteroids that might pose an impact threat to Earth. You might remember comet C/2019 Y4 (ATLAS) from earlier this year; it’s one of more than 40 comets discovered by these same telescopes. It appeared to be getting brighter but then suddenly broke apart into multiple pieces, shattering our hopes for a cool comet show in the night sky. Comet do that sometimes; they break up as they near the sun.

They do that because comets are typically fragile, icy bodies, unlike asteroids, which tend to be rocky or metallic. That’s why comets, typically, have tails and asteroids don’t. The tails come from volatile materials – ices – within a comet’s central nucleus, or core. Solar radiation can vaporize these fragile materials, causing them to stream out of the nucleus, carrying dust with them, forming the comet’s tail.

Asteroids don’t do this, typically. They typically don’t have the ices that become comet tails. But, as stated above, the lines sometimes blur. University of Hawai’i reported:

Early in June 2019, ATLAS reported what seemed to be a faint asteroid near the orbit of Jupiter. The Minor Planet Center designated the new discovery as 2019 LD2. Inspection of ATLAS images taken on June 10 by collaborators Alan Fitzsimmons and David Young at Queen’s University Belfast revealed its probable cometary nature. Follow-up observations by the University of Hawai?i’s J.D. Armstrong and his student Sidney Moss on June 11 and 13 using the Las Cumbres Observatory (LCO) global telescope network confirmed the cometary nature of this body.

Later, in July 2019, new ATLAS images caught 2019 LD2 again – now truly looking like a comet, with a faint tail made of dust or gas. The asteroid passed behind the sun and was not observable from the Earth in late 2019 and early 2020, but upon its reappearance in the night sky in April of 2020, routine ATLAS observations confirmed that it still looks like a comet. These observations showed that 2019 LD2 has probably been continuously active for almost a year.

And that’s interesting, too, because we don’t tend to think of cometary activity as something ongoing. It tends to happen when comets draw in near the sun. The volatile material leaves the comet’s surface, forming the tail and then, at some point, it’s used up. For 2019 LD2, the continuous activity for a year of observation prompts some questions. How long has this object been doing this? Why didn’t astronomers see this object before this?

A speck of light, on a field of starry specks.

Image of asteroid 2019 LD2 taken on June 11, 2019, using the Las Cumbres Observatory Global Telescope (LCOGT) Networks 1.0-meter telescope at Cerro Tololo, Chile. Image via JD Armstrong/ LCOGT/ IfA.

One answer may be that it only recently got to the place where we now see it. The astronomers’ statement said:

What makes 2019 LD2 so interesting is that we think most Jupiter Trojans were captured billions of years ago. Any surface ice that could vaporize to spew out gas and dust should have done so long ago, leaving the objects quietly orbiting as asteroids – not behaving like comets.

What could have made 2019 LD2 suddenly show cometary behavior? Maybe Jupiter captured it only recently from a more distant orbit where surface ice could still survive.

Or, there’s another possibility, one that has astronomers excited. This object could be revealing that, as predicted by some astronomers, the Trojan asteroids may be icier than your average asteroid. Alan Fitzsimmons said:
.

We have believed for decades that Trojan asteroids should have large amounts of ice beneath their surfaces, but never had any evidence until now. ATLAS has shown that the predictions of their icy nature may well be correct.

These astronomers said the comet-tail might be showing up now because 2019 LD2 recently suffered a landslide or an impact from another asteroid, exposing ice that used to be buried under layers of protective rock. The astronomers said:

New observations to find out are being acquired and evaluated.

What’s certain is that the universe is full of surprises – and surveys to guard the Earth from dangerous asteroids often make unexpected discoveries of harmless but fascinating objects that can reveal more about our solar system’s history.

Bottom line: Trojan asteroids orbit 60 degrees ahead of and behind Jupiter, in its wide orbit at 5 times Earth’s distance from the sun. Now the 1st Trojan asteroid – called 2019 LD2 – has been found with a comet-like tail.

Via University of Hawai’i



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Diagam showing the inner solar system, asteroid belt and Jupiter and its orbit, with locations of Trojan asteroids indicated.

Astronomers use the name Trojan asteroid for all the asteroids collected at Jupiter’s 2 stable Lagrange points, 60 degrees ahead of the planet in its orbit and 60 degrees behind. They further divide them into 2 camps with the Greek camp orbiting in front of Jupiter, and the Trojan camp trailing behind. The newly discovered Trojan with a comet-tail is orbiting ahead of Jupiter. Image via Wikimedia Commons.

Scientific language is like a net thrown over nature. Scientists try to name and categorize natural objects, and usually that process goes smoothly … but sometimes it doesn’t, as in 2006 when Pluto was demoted from major planet to dwarf planet. Pluto didn’t change. Our understanding of Pluto’s context in our solar system had evolved. Asteroids and comets also sometimes defy easy categorization. There’s 3200 Phaethon, for example, which has an asteroid name, but which is the parent body for December’s Geminid meteor shower; if you follow meteor showers, you know they stem from comets. Astronomers are discovering more and more objects that start out looking like asteroids, and later develop activity, such as comet-like tails. Today (May 21, 2020), the Institute for Astronomy at the University of Hawai’i announced a new asteroid-with-a-comet-tail in a very interesting place in our solar system. This object is moving along the orbit traveled by Jupiter around our sun. It’s thus considered a Trojan asteroid, the first Trojan asteroid known with a comet-like tail. The University of Hawai’i explained:

Trojan asteroids follow the same orbit as a planet, but stay either around 60 degrees ahead or 60 degrees behind along the orbit. Earth has at least one Trojan asteroid, and Neptune has dozens. Jupiter has hundreds of thousands. The Jupiter Trojan asteroids orbit the sun in two huge swarms, one swarm orbiting ahead of the planet (where 2019 LD2 was found) and one swarm orbiting behind it. The Trojan asteroids have been captured into these orbits by Jupiter’s strong gravity.

The discovery comes from the Asteroid Terrestrial-impact Last Alert System (ATLAS), a NASA-funded project that uses wide-field telescopes to scan for asteroids that might pose an impact threat to Earth. You might remember comet C/2019 Y4 (ATLAS) from earlier this year; it’s one of more than 40 comets discovered by these same telescopes. It appeared to be getting brighter but then suddenly broke apart into multiple pieces, shattering our hopes for a cool comet show in the night sky. Comet do that sometimes; they break up as they near the sun.

They do that because comets are typically fragile, icy bodies, unlike asteroids, which tend to be rocky or metallic. That’s why comets, typically, have tails and asteroids don’t. The tails come from volatile materials – ices – within a comet’s central nucleus, or core. Solar radiation can vaporize these fragile materials, causing them to stream out of the nucleus, carrying dust with them, forming the comet’s tail.

Asteroids don’t do this, typically. They typically don’t have the ices that become comet tails. But, as stated above, the lines sometimes blur. University of Hawai’i reported:

Early in June 2019, ATLAS reported what seemed to be a faint asteroid near the orbit of Jupiter. The Minor Planet Center designated the new discovery as 2019 LD2. Inspection of ATLAS images taken on June 10 by collaborators Alan Fitzsimmons and David Young at Queen’s University Belfast revealed its probable cometary nature. Follow-up observations by the University of Hawai?i’s J.D. Armstrong and his student Sidney Moss on June 11 and 13 using the Las Cumbres Observatory (LCO) global telescope network confirmed the cometary nature of this body.

Later, in July 2019, new ATLAS images caught 2019 LD2 again – now truly looking like a comet, with a faint tail made of dust or gas. The asteroid passed behind the sun and was not observable from the Earth in late 2019 and early 2020, but upon its reappearance in the night sky in April of 2020, routine ATLAS observations confirmed that it still looks like a comet. These observations showed that 2019 LD2 has probably been continuously active for almost a year.

And that’s interesting, too, because we don’t tend to think of cometary activity as something ongoing. It tends to happen when comets draw in near the sun. The volatile material leaves the comet’s surface, forming the tail and then, at some point, it’s used up. For 2019 LD2, the continuous activity for a year of observation prompts some questions. How long has this object been doing this? Why didn’t astronomers see this object before this?

A speck of light, on a field of starry specks.

Image of asteroid 2019 LD2 taken on June 11, 2019, using the Las Cumbres Observatory Global Telescope (LCOGT) Networks 1.0-meter telescope at Cerro Tololo, Chile. Image via JD Armstrong/ LCOGT/ IfA.

One answer may be that it only recently got to the place where we now see it. The astronomers’ statement said:

What makes 2019 LD2 so interesting is that we think most Jupiter Trojans were captured billions of years ago. Any surface ice that could vaporize to spew out gas and dust should have done so long ago, leaving the objects quietly orbiting as asteroids – not behaving like comets.

What could have made 2019 LD2 suddenly show cometary behavior? Maybe Jupiter captured it only recently from a more distant orbit where surface ice could still survive.

Or, there’s another possibility, one that has astronomers excited. This object could be revealing that, as predicted by some astronomers, the Trojan asteroids may be icier than your average asteroid. Alan Fitzsimmons said:
.

We have believed for decades that Trojan asteroids should have large amounts of ice beneath their surfaces, but never had any evidence until now. ATLAS has shown that the predictions of their icy nature may well be correct.

These astronomers said the comet-tail might be showing up now because 2019 LD2 recently suffered a landslide or an impact from another asteroid, exposing ice that used to be buried under layers of protective rock. The astronomers said:

New observations to find out are being acquired and evaluated.

What’s certain is that the universe is full of surprises – and surveys to guard the Earth from dangerous asteroids often make unexpected discoveries of harmless but fascinating objects that can reveal more about our solar system’s history.

Bottom line: Trojan asteroids orbit 60 degrees ahead of and behind Jupiter, in its wide orbit at 5 times Earth’s distance from the sun. Now the 1st Trojan asteroid – called 2019 LD2 – has been found with a comet-like tail.

Via University of Hawai’i



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Wolf spiders may turn to cannibalism in a warming Arctic

Wolf spiders in a warming Arctic are getting bigger, reproducing more and eating different foods, including other spiders. The changes could initiate a new cascade of food web interactions that could potentially alleviate some impacts of global warming. That’s according to a study published May 5, 2020, in the peer-reviewed Journal of Animal Ecology.

The research, conducted at two sites in the Alaskan Arctic, suggests that as female wolf spiders become larger and produce more offspring, competition among them increases, triggering higher rates of cannibalism and reducing the number of young spiders that survive to adulthood.

Washington University biologist Amanda Koltz is first author of the new study. She said in a statement:

Although cannibalism is probably not the best dietary choice for these spiders, our field and experimental data suggest that when there are lots of spiders around, they turn to cannibalism more frequently. It’s likely a reflection of increased competition among the spiders for resources.

Closeup of big brown spider in twiggy vegetation.

Wolf spiders are among the most important predators in the Alaskan Arctic. Image via Ashley Asmus/ Washington University.

Animals such as spiders that regulate their body temperature externally are particularly likely to experience changes as a result of warming. In some areas of the Arctic, biologists have found that wolf spiders are bigger following years with longer summers. This suggests that as climate change continues to warm up the Arctic, wolf spider body sizes will generally become larger.

At the same time, female spiders tend to produce more offspring as they become larger, so bigger spiders might translate to more spiders in the future. But whether this change actually results in more spiders in the wild remains an important question. Koltz said:

Space and resources on the tundra are finite.

In observations at sites in the Alaskan Arctic, Koltz and her team discovered that the presence of larger female spiders was associated with fewer juvenile spiders. This was unexpected, as larger females produce more offspring. An analysis found that the spiders at the site with larger females had different diets than at the site with smaller females.

Man and woman holding a long rope between them in tundra landscape with hills in the background.

The researchers setting up spider traps at a field site in Alaska. Read more about how the researchers conducted the new study here. Image via Nick LaFave/ Washington University.

The dietary shift was consistent with what a shift toward cannibalism would look like, Koltz said, suggesting that where spiders were larger – and reproductive rates higher – spiders cannibalized each other more often. This idea was further supported by the experimental results.

Bottom line: According to a study, wolf spiders in a warming Arctic are getting bigger, reproducing more and eating different foods, including other spiders. The changes could initiate a new cascade of food web interactions that could potentially alleviate some impacts of global warming.

Source: Impacts of female body size on cannibalism and juvenile abundance in a dominant arctic spider

Via Washington University



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Wolf spiders in a warming Arctic are getting bigger, reproducing more and eating different foods, including other spiders. The changes could initiate a new cascade of food web interactions that could potentially alleviate some impacts of global warming. That’s according to a study published May 5, 2020, in the peer-reviewed Journal of Animal Ecology.

The research, conducted at two sites in the Alaskan Arctic, suggests that as female wolf spiders become larger and produce more offspring, competition among them increases, triggering higher rates of cannibalism and reducing the number of young spiders that survive to adulthood.

Washington University biologist Amanda Koltz is first author of the new study. She said in a statement:

Although cannibalism is probably not the best dietary choice for these spiders, our field and experimental data suggest that when there are lots of spiders around, they turn to cannibalism more frequently. It’s likely a reflection of increased competition among the spiders for resources.

Closeup of big brown spider in twiggy vegetation.

Wolf spiders are among the most important predators in the Alaskan Arctic. Image via Ashley Asmus/ Washington University.

Animals such as spiders that regulate their body temperature externally are particularly likely to experience changes as a result of warming. In some areas of the Arctic, biologists have found that wolf spiders are bigger following years with longer summers. This suggests that as climate change continues to warm up the Arctic, wolf spider body sizes will generally become larger.

At the same time, female spiders tend to produce more offspring as they become larger, so bigger spiders might translate to more spiders in the future. But whether this change actually results in more spiders in the wild remains an important question. Koltz said:

Space and resources on the tundra are finite.

In observations at sites in the Alaskan Arctic, Koltz and her team discovered that the presence of larger female spiders was associated with fewer juvenile spiders. This was unexpected, as larger females produce more offspring. An analysis found that the spiders at the site with larger females had different diets than at the site with smaller females.

Man and woman holding a long rope between them in tundra landscape with hills in the background.

The researchers setting up spider traps at a field site in Alaska. Read more about how the researchers conducted the new study here. Image via Nick LaFave/ Washington University.

The dietary shift was consistent with what a shift toward cannibalism would look like, Koltz said, suggesting that where spiders were larger – and reproductive rates higher – spiders cannibalized each other more often. This idea was further supported by the experimental results.

Bottom line: According to a study, wolf spiders in a warming Arctic are getting bigger, reproducing more and eating different foods, including other spiders. The changes could initiate a new cascade of food web interactions that could potentially alleviate some impacts of global warming.

Source: Impacts of female body size on cannibalism and juvenile abundance in a dominant arctic spider

Via Washington University



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Mercury and Venus pair up May 21 and 22

The sun’s innermost planets, Mercury and Venus, will pair up in the west after sunset – their closest pairing for all of 2020 – on May 21 or 22. These two worlds will pass within only one degree on the sky’s dome. That’s approximately the width of your little finger held at arm’s length. Their pairing takes place low in the western twilight sky, shortly after sunset. Bright twilight will make Mercury hard to see. But Venus is very bright. Its brightness will pierce the twilight, making Venus an interesting and beautiful object to see now. Plus Venus can help you find and identify Mercury.

To witness the unfolding of this grand celestial event, find an unobstructed horizon in the direction of sunset. As twilight deepens into darkness, watch for Venus to pop out 1/2 hour (or sooner) after sunset. Given clear skies, it’ll be hard to miss Venus, as it’s the 3rd-brightest celestial body to light up the heavens, after the sun and moon, respectively. Luckily, Venus is our ticket to catching Mercury.

Although Mercury pales next to Venus, Mercury still shines as brilliantly as a 1st-magnitude star. Forty-five minutes to one hour after sunset, you may well be able to spot Mercury with the eye alone. If you can’t see Mercury otherwise, aim binoculars at Venus to view Mercury and Venus in a single binocular field.

By the way, these objects are moving rapidly on the sky’s dome with respect to each other. Your perspective on them also shifts as seen from various parts of the globe. Try Stellarium for a precise view from your location. And – no matter where you are – you can recognize Mercury on May 21 and 22 as the brightest object near Venus in the evening twilight.

Just be sure to catch them not long after the sun goes down.

Very bright Venus in a twilight sky, and Mercury below Venus.

View at EarthSky Community Photos. | Jenney Disimon in Sabah, N. Borneo caught Venus and Mercury on May 19, 2020. Thank you, Jenney! See more Venus-Mercury photos at EarthSky Community Photos.

The Northern Hemisphere has the advantage for watching Mercury and Venus, because these two worlds set later after the sun as seen from latitudes. We give Venus’ approximate setting time at various latitudes for the evenings around May 21 and 22, 2020, given an absolutely level horizon:

60 degrees north latitude
Venus sets 2 1/2 hours after the sun

40 degrees north latitude:
Venus sets 1 1/2 hours after the sun

Equator (0 degrees latitude)
Venus sets 1 1/4 hours after the sun

35 degrees south latitude
Venus sets one hour after the sun

Mosaic showing Venus and Mercury setting.

View larger at EarthSky Community Photos. | Peter Lowenstein in the Southern Hemisphere (Mutare, Zimbabwe) made a successful attempt to photograph Venus and Mercury setting after sunset on Monday, May 18, 2020. In the larger version of this mosaic, you can see both planets. Venus is bright, and above the crest of the hill. Mercury is fainter and lower in the sky, above the lower ridgeline of the hill, in the bottom middle of the photo. You can see that Mercury comes close to setting behind the hill as the mosaic progresses from upper left to bottom right (as time passes after sunset). Thank you, Peter! See more Venus-Mercury photos at EarthSky Community Photos.

Day by day, relative to the setting sun, Mercury will climb upward whereas Venus will fall downward. In a few more weeks – June 3, 2020 – Venus will transition out of the evening sky and into the morning sky. Mercury, on the other hand, will reach its greatest elongation from the setting sun on June 4, 2020. Over the next two weeks, watch for Venus to set sooner after sunset daily, while Mercury (though fading somewhat each day) stays out longer after sunset daily. After Mercury reaches its greatest elongation from the sun on June 4, 2020, it’ll fall sunward once again, to transition out of the evening sky and into the morning sky on July 1, 2020.

Diagram of Mercury and Venus conjunction.

A bird’s-eye view of the north side of the inner solar system (Mercury, Venus, Earth and Mars) when Mercury and Venus are in conjunction (as seen from Earth) on May 22, 2020, at 7 UTC. Image via Solar System Live.

Even though Mercury and Venus appear close together on the sky’s dome, they are not truly close together in space. These two words only reside near the same line of sight. Look above at the diagram of the inner solar system (Mercury, Venus, Earth and Mars). At present, Mercury is more than three times Venus’ distance from Earth. Astronomers often measure solar system objects in terms of the astronomical unit (Earth-sun distance). At their conjunction on May 22, 2020, at 7 UTC, Mercury is one astronomical unit and Venus is 0.3 astronomical unit distant from Earth.

As awesome as the Mercury/Venus pairing will be on May 21 and 22, 2021, more celestial drama is yet to come. Watch for the young waxing crescent moon to join up with these bright planets for several days, centered on or near May 24, 2020. (See sky chart below.)

Bottom line: For the Northern Hemisphere, late May/early June 2020 presents the best chance to see Mercury in the evening sky for the rest of 2020. From the Southern Hemisphere, Mercury will be harder to see, more deeply buried in evening twilight. No matter where you are on Earth, trying using Venus to find Mercury on May 21 and 22, 2020!



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The sun’s innermost planets, Mercury and Venus, will pair up in the west after sunset – their closest pairing for all of 2020 – on May 21 or 22. These two worlds will pass within only one degree on the sky’s dome. That’s approximately the width of your little finger held at arm’s length. Their pairing takes place low in the western twilight sky, shortly after sunset. Bright twilight will make Mercury hard to see. But Venus is very bright. Its brightness will pierce the twilight, making Venus an interesting and beautiful object to see now. Plus Venus can help you find and identify Mercury.

To witness the unfolding of this grand celestial event, find an unobstructed horizon in the direction of sunset. As twilight deepens into darkness, watch for Venus to pop out 1/2 hour (or sooner) after sunset. Given clear skies, it’ll be hard to miss Venus, as it’s the 3rd-brightest celestial body to light up the heavens, after the sun and moon, respectively. Luckily, Venus is our ticket to catching Mercury.

Although Mercury pales next to Venus, Mercury still shines as brilliantly as a 1st-magnitude star. Forty-five minutes to one hour after sunset, you may well be able to spot Mercury with the eye alone. If you can’t see Mercury otherwise, aim binoculars at Venus to view Mercury and Venus in a single binocular field.

By the way, these objects are moving rapidly on the sky’s dome with respect to each other. Your perspective on them also shifts as seen from various parts of the globe. Try Stellarium for a precise view from your location. And – no matter where you are – you can recognize Mercury on May 21 and 22 as the brightest object near Venus in the evening twilight.

Just be sure to catch them not long after the sun goes down.

Very bright Venus in a twilight sky, and Mercury below Venus.

View at EarthSky Community Photos. | Jenney Disimon in Sabah, N. Borneo caught Venus and Mercury on May 19, 2020. Thank you, Jenney! See more Venus-Mercury photos at EarthSky Community Photos.

The Northern Hemisphere has the advantage for watching Mercury and Venus, because these two worlds set later after the sun as seen from latitudes. We give Venus’ approximate setting time at various latitudes for the evenings around May 21 and 22, 2020, given an absolutely level horizon:

60 degrees north latitude
Venus sets 2 1/2 hours after the sun

40 degrees north latitude:
Venus sets 1 1/2 hours after the sun

Equator (0 degrees latitude)
Venus sets 1 1/4 hours after the sun

35 degrees south latitude
Venus sets one hour after the sun

Mosaic showing Venus and Mercury setting.

View larger at EarthSky Community Photos. | Peter Lowenstein in the Southern Hemisphere (Mutare, Zimbabwe) made a successful attempt to photograph Venus and Mercury setting after sunset on Monday, May 18, 2020. In the larger version of this mosaic, you can see both planets. Venus is bright, and above the crest of the hill. Mercury is fainter and lower in the sky, above the lower ridgeline of the hill, in the bottom middle of the photo. You can see that Mercury comes close to setting behind the hill as the mosaic progresses from upper left to bottom right (as time passes after sunset). Thank you, Peter! See more Venus-Mercury photos at EarthSky Community Photos.

Day by day, relative to the setting sun, Mercury will climb upward whereas Venus will fall downward. In a few more weeks – June 3, 2020 – Venus will transition out of the evening sky and into the morning sky. Mercury, on the other hand, will reach its greatest elongation from the setting sun on June 4, 2020. Over the next two weeks, watch for Venus to set sooner after sunset daily, while Mercury (though fading somewhat each day) stays out longer after sunset daily. After Mercury reaches its greatest elongation from the sun on June 4, 2020, it’ll fall sunward once again, to transition out of the evening sky and into the morning sky on July 1, 2020.

Diagram of Mercury and Venus conjunction.

A bird’s-eye view of the north side of the inner solar system (Mercury, Venus, Earth and Mars) when Mercury and Venus are in conjunction (as seen from Earth) on May 22, 2020, at 7 UTC. Image via Solar System Live.

Even though Mercury and Venus appear close together on the sky’s dome, they are not truly close together in space. These two words only reside near the same line of sight. Look above at the diagram of the inner solar system (Mercury, Venus, Earth and Mars). At present, Mercury is more than three times Venus’ distance from Earth. Astronomers often measure solar system objects in terms of the astronomical unit (Earth-sun distance). At their conjunction on May 22, 2020, at 7 UTC, Mercury is one astronomical unit and Venus is 0.3 astronomical unit distant from Earth.

As awesome as the Mercury/Venus pairing will be on May 21 and 22, 2021, more celestial drama is yet to come. Watch for the young waxing crescent moon to join up with these bright planets for several days, centered on or near May 24, 2020. (See sky chart below.)

Bottom line: For the Northern Hemisphere, late May/early June 2020 presents the best chance to see Mercury in the evening sky for the rest of 2020. From the Southern Hemisphere, Mercury will be harder to see, more deeply buried in evening twilight. No matter where you are on Earth, trying using Venus to find Mercury on May 21 and 22, 2020!



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Crescent Venus, moon, sun

3 crescents - Venus, the moon, the eclipsed sun - all at about the same phase.

View at EarthSky Community Photos. | Eliot Herman in Tucson, Arizona wrote: “This is a comparison of crescent images as a montage. Imagery acquired in May 2020 for Venus (in Tucson AZ) upper left, September 2019 for the moon (in Tucson AZ) in the middle, and during the total solar eclipse in July 2019 (in Chile) on the bottom right. Venus was imaged using a 180 mm Skywatcher Mak telescope and the moon a with a Questar Mak telescope. The sun was imaged with 500 mm Nikon lens. Venus is not to scale.” Thank you, Eliot! See more photos of Venus in a crescent phase in May, 2020



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3 crescents - Venus, the moon, the eclipsed sun - all at about the same phase.

View at EarthSky Community Photos. | Eliot Herman in Tucson, Arizona wrote: “This is a comparison of crescent images as a montage. Imagery acquired in May 2020 for Venus (in Tucson AZ) upper left, September 2019 for the moon (in Tucson AZ) in the middle, and during the total solar eclipse in July 2019 (in Chile) on the bottom right. Venus was imaged using a 180 mm Skywatcher Mak telescope and the moon a with a Questar Mak telescope. The sun was imaged with 500 mm Nikon lens. Venus is not to scale.” Thank you, Eliot! See more photos of Venus in a crescent phase in May, 2020



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