The leading expert on infectious diseases, Dr. Anthony Fauci, responds to allegations made by Senator Rand Paul (R-KY) as he testifies before the Senate Health, Education, Labor, and Pensions Committee on Capitol Hill in Washington, DC, the United States, on July 20, 2021 .
J. Scott Applewhite | Reuters
The US will likely start distributing Pfizer Covid-19 booster vaccinations on a large scale in the week of September 20, but Moderna’s vaccine launch could be delayed, said Dr. Anthony Fauci, Chief Medical Officer of the White House on Sunday.
The Biden government has announced plans to offer people who received the Pfizer and Moderna shots a third dose pending approval from health officials. The US recommends an additional injection eight months after the second dose.
Only the Pfizer Vaccine Booster can get Food and Drug Administration and Centers for Disease Control and Prevention approval in time for launch the week of September 20, Fauci said on CBS’s Face the Nation. People who have received Moderna shots may have to wait longer as the company waits for regulators to sign off a third dose.
“Looks like Pfizer has its data, will likely meet the deadline,” the director of the National Institute of Allergies and Infectious Diseases told CBS. “We hope Moderna could do that too, so we could do it at the same time.”
“But if not, we’ll do it one at a time,” he continued. “So the bottom line is that at least part of the plan is very likely to be implemented, but ultimately the entire plan will be implemented.”
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Later on Sunday, Fauci told CNN that for people who received two doses of the Moderna vaccine, “it is better to wait for a third dose of Moderna” than to get an injection from Pfizer. He noted that the US plans to release data on mixing vaccines from different manufacturers in the coming weeks.
The Pfizer-BioNTech Covid-19 vaccine is the most widely used vaccine in the United States. According to CDC data, more than 95 million people have received the full two-shot regimen.
Approximately 66 million people were fully vaccinated with the Moderna syringe. Approximately 14 million people have now received the single dose from Johnson & Johnson. Regulators haven’t announced any plans for a J&J booster.
When calling for third doses of Pfizer and Moderna, US health officials cited CDC data which found that protection against infection waned several months after the second injection. According to the CDC, more than 1.3 million people received an extra vaccination after the US approved it for certain immunocompromised people.
White House Chief of Staff Ron Klain told CNN’s State of the Union on Sunday that the government will have booster vaccinations “ready for use” when regulators approve them for wider use.
An FDA advisory panel will review Pfizer’s application for a booster vaccination on September 17th, just three days before the injections are due to begin.
The Biden government’s booster plan has sparked criticism in the US and around the world. The World Health Organization has urged wealthy countries with higher vaccination rates to withhold further vaccinations until poorer countries can give more people their first doses of vaccine.
As the virus spreads around the world, the prospect of new – and potentially more dangerous – variants increases.
The White House has defended its booster plan, citing US donations of vaccine doses to other countries. Last month, Fauci told CNBC that the US has given 120 million doses to 80 countries.
“We do both,” he said of vaccinating Americans and people around the world.
Last month, civil rights icon Rev. Jesse Jackson and his wife Jacqueline Jackson were hospitalized after testing positive for COVID-19. Her family issued a statement on Friday to inform her of her condition.
Jacqueline Jackson was released from Northwestern Memorial Hospital and sent home after battling the virus. However, Jesse Jackson is still at the Shirley Ryan AbilityLab, where he is receiving intensive occupational and physical therapy. Her son Jesse Jackson Jr. shared photos of Jesse Jackson Sr. while he was at the facility and admitted that his father is now COVID negative while he continues his treatment.
The family statement went on to say, “We urge you to keep them in your prayers. The love that has been poured out from around the world for our families during this time of sickness and hardship has healed our parents and for each of you who have prayed and expressed concern we are grateful as we continue to love Expressing concern for the millions of people affected by the COVID-19 virus and its variants.
As we previously reported, Rev. Jackson was diagnosed with Parkinson’s disease in 2015 and he spoke publicly about his diagnosis in 2017, which is the reason for his physical therapy.
Rev. Jackson was fully vaccinated prior to contracting COVID-19, and his wife, Jacqueline, was not due to any previous illness.
We continue to uphold Rev. Jackson and his wife, Jacqueline, in prayer as they continue to recover.
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A supernova is the brilliant end of a giant star. For a brief moment of cosmic time, a star makes one final effort to keep shining, only to fade and collapse on itself. The end result is either a neutron star or a black hole with stellar mass. We have generally assumed that all stars above about ten solar masses will end up as a supernova, but a new study suggests that this is not the case.
In contrast to the famous Type Ia supernovae, which can result from the merging or interaction of two stars, large stars go through a so-called core collapse supernova. Stars survive by balancing heat and pressure against gravity. As more elements merge, a large star must generate heat by merging heavier and heavier elements. This eventually forms a layer of regions where different elements are fused. But this chain can only be worn up to the iron. After that, merging heavier elements costs energy instead of releasing them. So the core collapses, creating a shock wave that tears the star apart.
The onion skin model of a dying star, not to scale. Photo credit: RJ Hall
In models of large dying stars, core collapse supernovae occur for stars over 9-10 solar masses up to about 40-50 solar masses. Above this mass, stars are so massive that they will likely collapse straight into a black hole without becoming a supernova. Extremely massive stars on the order of 150 solar masses or more could explode as a hypernova. These beasts do not explode because of a core collapse, but rather because of an effect known as pair instability, in which colliding photons generated in the core create pairs of electrons and positrons.
This new study suggests that the upper mass limit for core collapse supernovae could be much lower than we thought. The team studied the elemental abundances of a pair of colliding galaxies known as Arp 299. As the galaxies are colliding, the region is a breeding ground for supernovae. As a result, the elemental abundances of Arp 299 should largely depend on the elements dropped in supernova explosions. They measured the abundance ratio of iron to oxygen and the ratio of neon and magnesium to oxygen. They found that the Ne / O and Mg / O ratios were similar to the sun, while the Fe / O ratio was much lower than the sun’s level. Iron is most efficiently thrown into the universe through large supernovae.
A Hubble image of colliding galaxies known as Arp 299. Photo credit: NASA, ESA, Hubble Heritage Collaboration, and A. Evans
The ratios observed by the team did not agree with standard core collapse models, but they found that the data was in good agreement with supernova models when ruling out supernovae over about 23 to 27 solar masses. In other words, if stars collapse into black holes above about 27 solar masses, then models and observations will agree.
This work does not conclusively prove that the upper mass limit for supernovae is smaller than we thought. It is also possible that supernovae produce higher amounts of neon and magnesium than the models predict. Either way, it is clear that we still have a great deal to learn about the last dying breaths of great stars.
Reference: Mao, Junjie, et al. “Elemental abundance of the hot atmosphere of the glowing infrared galaxy Arp 299.” The Astrophysical Journal Letters 918.1 (2021): L17.
ATLANTA – Nick Saban really wanted us to believe he was concerned. That he was worried. That maybe sometime in the last month of preparation for Alabama’s first game of the 2021 college football season, he sat at the dining table with his wife, Miss Terry, wringing their hands and frowning at what might be happening in Atlanta over Labor Day Weekend.
Forget that in previous season openers he was on the neutral side 10-0. Or that six of these 10 victories were achieved against ranked opponents. Or that those six wins were earned with an average of almost 27 points per game.
Instead, the greatest college football coach of all time, having had the best season his GOAT era has ever produced, held onto his glut of discomfort on Saturday morning. Just hours before reigning national champions Alabama took on an often “resurgent” team from Miami Hurricanes that wanted to bring down the top 10 by containing the tide, Saban spoke in almost muffled tones. No smile. Just a premonition.
“It’s always a little, did I do a good job? Saban told ESPN’s Marty & McGee in the College Football Hall of Fame when asked if he is still nervous in the first game after more than a quarter of a century as college head coach. “There’s a bit of fear there.”
2 relatives
He spoke about the weight of expectations, the challenge of replacing a historically unstoppable 2020 offensive fueled by a now-vanished Heisman Trophy winner wide receiver and an NFL first-round draft pick at the quarterback. He recalled that in addition to hiring two new coordinators, he had only one returning assistant on his entire offensive staff.
When Saban listed it all, it actually sounded convincingly insurmountable.
And then his team beat the 14th Miami 44-13. The Tide scored 501 yards offensive when replacement quarterback Bryce Young set Alabama first-start pass records with 344 yards and four touchdowns. The receivers responsible for getting into the tunnels of last year’s All-Stars did so en masse, with a whopping 10 players taking in at least one catch.
The man who spent his mornings convincing us of his lack of confidence was spending his stoppage time downright dizzy at the newfound confidence he’d just seen in his young locker room.
Bryce Young looked like a veteran in his first start, throwing 344 yards and four touchdowns. Kevin C. Cox / Getty Images
“I think that’s really important, especially when you have a lot of new players who don’t have a lot of experience,” said the 69-year-old coach after posing with these youngsters while wearing an antique leather helmet that was awarded by the club became chick-fil-a kickoff game. “When you get into the game and get some success, the reward for all the work you’ve put in, it really builds confidence. Hopefully it will help them develop and improve.”
Seeing what happened at the science fiction Mercedes-Benz stadium on Saturday afternoon was, in fact, like being trapped in some sort of Marvel Comics time warp. A solid four hour houndstooth déjà vu.
Stop me if you’ve heard this before. Don’t actually stop me. Continue reading. Because after tonight, this story will not repeat itself for a long time.
2008. Week 1. Atlanta. No. 24 Alabama upset No. 9 Clemson 34-10. The win ignites Alabama’s return to big time as it wins 12 regular season games. Clemson falls apart completely and fires trainer Tommy Bowden.
2009. Week 1. Atlanta. Fifth-placed Alabama beats seventh-placed Virginia Tech 34-24. Alabama wins its first national championship under Saban, while the Hokies pale into a three-loss season.
2014. Week 1. Atlanta. No. 2 Alabama 33, West Virginia 23.
2019. Week 1. Atlanta. No. 2 Alabama 49, Duke 3.
And those are just the games that are played in Atlanta. The biggest victories on neutral locations were in Orlando and Texas. There was the 52-6 beating of No. 20 USC in 2016, the 2012 and ’15 Beatdowns of Michigan and Wisconsin, both in Arlington, Texas. And then the cruelest breakdown of all, a 17-point win over 3rd Florida State in Orlando, which marked the beginning of the end for Jimbo Fisher’s time with the Seminoles.
Every open act won, the Battle of Atlanta, Orlando or Arlington, served the ultimate purpose of putting someone in their place. Maybe it was an old school powerhouse that needed to be told Alabama was real. Maybe it was an upstart who thought he might bring down the Alabama playoff blockade. Perhaps it was just a showcase displayed in front of a nation of recruits, especially those who lived in the neighborhood of the teams that were just being wiped out by the flood.
John Metchie III scored the game’s first touchdown and was one of 10 Alabama receivers to catch a pass against Miami. David J. Griffin / Icon Sportswire
And in at least some cases, it has felt like Saban let an entire conference know that their best team isn’t ready for SEC prime time just yet.
Saturday’s win over Miami felt like it covered all of the above.
So the thousands of Alabama fans walking up Peachtree Street on Saturday night celebrated the victory but also mourned days like this. Now, after a decade of neutral page openings, Alabama has booked home and home series with Power 5 opponents through 2035.
Will it be worth losing the $ 5 million Bama received from the Atlanta Bowl people every September? They say yes by adding more value to Tuscaloosa season ticket holders.
Because of me. But will it be worth losing the mainstream mojo and messages on it during this 11-0 season opening streak?
“I wouldn’t worry too much about Coach Saban in the future,” said Miami’s head coach Manny Diaz with a laugh. “So far it seems to be working for him.”
How EPA employees feel about themselves with the release of the report.
Roger Caiazza sent me the email below. It speaks for itself.
Subject: EPA Report Shows Disproportionate Impacts of Climate Change on Socially Vulnerable Populations
EPA Report Shows Disproportionate Impacts of Climate Change on Socially Vulnerable Populations in the United States
WASHINGTON (Sept. 2, 2021) — A new EPA analysis released today shows that the most severe harms from climate change fall disproportionately upon underserved communities who are least able to prepare for, and recover from, heat waves, poor air quality, flooding, and other impacts. EPA’s analysis indicates that racial and ethnic minority communities are particularly vulnerable to the greatest impacts of climate change. Climate Change and Social Vulnerability in the United States: A Focus on Six Impact Sectors is one of the most advanced environmental justice studies to date that looks at how projected climate change impacts may be distributed across the American public.
“The impacts of climate change that we are feeling today, from extreme heat to flooding to severe storms, are expected to get worse, and people least able to prepare and cope are disproportionately exposed,” said EPA Administrator Michael S. Regan “This report punctuates the urgency of equitable action on climate change. With this level of science and data, we can more effectively center EPA’s mission on achieving environmental justice for all.”
EPA’s new, peer-reviewed report shows the degree to which four socially vulnerable populations— defined based on income, educational attainment, race and ethnicity, and age—may be more exposed to the highest impacts of climate change. The report quantifies six types of impacts, including those to health from changes in air quality and extreme temperature, disruptions to weather-exposed workers, and flooding threats to property.
Key findings of the report include:
That Black and African American individuals are projected to face higher impacts of climate change for all six impacts analyzed in this report, compared to all other demographic groups. For example, with 2°C (3.6°F) of global warming, Black and African American individuals are:
34% more likely to currently live in areas with the highest projected increases in childhood asthma diagnoses. This rises to 41% under 4°C (7.2°F) of global warming.
40% more likely to currently live in areas with the highest projected increases in extreme temperature related deaths. This rises to 59% under 4°C of global warming.
That Hispanics and Latinos have high participation in weather-exposed industries, such as construction and agriculture, which are especially vulnerable to the effects of extreme temperatures. With 2°C (3.6°F) of global warming, Hispanic and Latino individuals are 43% more likely to currently live in areas with the highest projected reductions in labor hours due to extreme temperatures. With regards to transportation, Hispanic and Latino individuals are about 50% more likely to currently live in areas with the highest estimated increases in traffic delays due to increases in coastal flooding.
This significant study represents an important milestone in understanding the future impacts of climate change on different American populations, especially under resourced communities. Due to data and modeling limitations, this study is limited to the contiguous U.S. Future work will enhance both the coverage of other important areas, such as Hawaii and Alaska, and will explore additional impact sectors and measures of social vulnerability.
Today’s analysis will help further efforts being taken by the Biden Administration across the Federal government to advance environmental justice and to address the disproportionate impacts that climate change is having on vulnerable communities. During his first weeks in office, President Biden issued Executive Order 14008 on Tackling the Climate Crisis at Home and Abroad, which established the first-ever White House Environmental Justice Advisory Council, the White House Environmental Justice Interagency Council, and the Justice40 Initiative. Through the Justice40 Initiative, the Federal government is, for the first time in history, working to ensure that at least 40-percent of climate and clean energy investment benefits flow to disadvantaged communities.
Access the report: https://www.epa.gov/cira/social-vulnerability-report
Information about climate change: https://www.epa.gov/climate-change
Information about environmental justice: https://www.epa.gov/environmentaljustice
People line up to test for coronavirus disease (COVID-19) in a mobile test car on August 27, 2021 in New York City.
Brendan McDermid | Reuters
The US goes into Labor Day weekend with just over four times as many Covid-19 cases and more than twice as many hospital admissions as it did at that time last year – despite 62% of the American population having been vaccinated with at least one dose.
The US and the world are nowhere near where health officials hoped and thought we would be 20 months after the pandemic – and more than eight months after vaccines came out with efficacy rates of around 95%.
Although the outbreak is significantly worse than 2020 on most measures, the delta variant, vaccines, and open schools make it difficult to predict how the pandemic will develop, doctors and scientists say.
“Right now there is a lot more uncertainty. The dynamic interaction between variants and vaccine and especially unvaccinated persons and the type of game changer of the Delta variant leads to a lot of uncertainty as to what the case will bring, “said Dr. Barbara Taylor, Assistant Dean and Infectious Disease Specialist at the University of Texas Health Science Center at San Antonio.
The Centers for Disease Control and Prevention has advised unvaccinated Americans against traveling over the holiday weekend because they feared the celebrations could trigger further spikes in cases.
On the way to Labor Day 2020, the U.S. saw a summer spike with the average daily cases spike in July from about 67,000 per day to an average of just over 41,000 new cases per day in the week leading up to Labor Day, data released by the Johns Hopkins University shows. New cases this week are at their highest level since January, averaging 166,000 per day for the past seven days.
However, the number of new cases is increasing much more slowly than in recent weeks, and many scientists are predicting that they will soon decline. New cases rose 7% last week, nearly a third of the seven-day jump from 26% just three weeks ago, the data said.
“It is true that cases, hospital admissions and deaths are higher than last Labor Day, especially in most southern states,” said Lawrence Gostin, director of the World Health Organization’s Collaborating Center on National and Global Health Law. “That was very surprising because we now have highly effective vaccines.”
However, the effectiveness of all three US-approved vaccines – Pfizer, Moderna, and Johnson & Johnson – have declined since they were launched. Scientists have found that protection wears off over time. The highly contagious Delta variant is also a game changer. It spreads more easily and quickly than other variants, according to the CDC, and infects both unvaccinated and vaccinated people.
The viral load in the nasal cavity is so high, an estimated 1,000 times higher than other strains, that scientists in Australia say they followed a case where a man became infected with just 5 to 10 seconds of exposure. The small fraction of fully vaccinated people who get Covid, even an asymptomatic case, are just as capable of spreading it as unvaccinated people, officials warned. The Delta variant now accounts for 99% of all newly sequenced cases in the United States
“The Delta variant, as we’ve seen with the development of Covid-19 over the past year and a half, continues to curve us, and I think the best advice is to be careful and careful,” Dr. Nusheen Ameenuddin, a Mayo Clinic pediatrician said in an interview.
The good news is that Delta seems to be on its way in the US and there are no more new people to infect as vaccination rates rise and others gain natural immunity after recovering from the virus, doctors and scientists say.
The number of new admissions to hospitals has finally changed after weeks of steady growth, with the seven-day average of daily admissions dropping 1.7% over the past week, CDC data shows. Still, more than 100,000 Americans are currently being hospitalized, compared to about 41,000 the same week a year ago, according to the Department of Health and Human Services, up from levels as of late January this year.
The big question is: how long does immunity last? Studies show that the vaccines’ effectiveness wears off about two months after the second vaccination and then really loses protection five to eight months after the full vaccination, US officials say.
“We can see periodic waves of this until there is adequate protection at the community level, and hopefully it will be through vaccination rather than recovery from natural infection,” said Dr. Isaac Bogoch, an infectious disease doctor at the University of Toronto. “I know we all want the pandemic to be over, but it’s not. We’re closer to the end in countries with access to vaccination, but it’s not over yet. “
It was in St. Peter that questions about Mercury’s sexuality arose. Another student Janet Smith, now a girl school teacher, remembered him as “an extremely thin, intense boy who had a habit of calling a ‘darling’ which I must say seemed a bit cowardly.”
“It just wasn’t something guys did back then,” she said in Lesley-Ann Jones‘Mercury: An Intimate Biography of Freddie Mercury. “It was accepted that Freddie was gay when he was here. Normally it would be, ‘Oh god you know, it’s just awful.’ But somehow it wasn’t with Freddie. It was okay. “
Mercury returned to Zanzibar in 1963, the same year that British colonial rule ended, resulting in a revolution on the island the following year, in which poor Africans targeted the wealthier Indian population. As a result, the Bulsara family fled to London and eventually settled in nearby Feltham, Middlesex. After leaving Farrokh in Mumbai, despite still using Bulsara as his last name, Mercury enrolled at Isleworth Polytechnic in West London to study graphic design. But soon he was caught up in the era of swinging London.
“Most of our family are lawyers or accountants, but Freddie insisted he wasn’t smart enough to want to make music and sing,” his mother told The Telegraph in 2012, laughing. “My husband and I thought it was a phase he was going to grow out of and we expected that he would soon regain his senses and get back to real study. It didn’t happen.”
The top seeded women Ash Barty suffered a surprising loss to the American Shelby Rogers and lost 6-2, 1-6, 7-6 (5) in the third round of the US Open on Saturday evening in New York.
Rogers, ranked 43rd in the world, started the match in good shape with an early break on the way to completing the first set. Australia’s world number 1 fought back hard in the second to drive the match into a crucial set.
Barty started the third with a break but was broken twice herself trying to play the match off.
Rogers refused to turn, forcing the match to a tie-break where she kept her nerve for a close win.
The duo had previously faced each other five times, with the Australian winning each time. Despite these defeats, Rogers had nothing but good things to say about Barty, as she praised her encouraging nature and ability to deal with real adversity this year.
“She’s one of the most professional people I’ve ever met in my life, as well as a good person, a fun person,” said Rogers after the game. “She is super down to earth. I mean she’s one of my favorite people.
“I was joking before, every time I lost to her I can’t be mad because she’s such a nice person. It’s like, man, she just kicked my butt, but then she says : “Oh, you’ll find it someday. ‘ She encourages everyone around her and brings up energy wherever she goes.
“I can’t say how much respect I have for her and what a great representative she is for women’s tennis.
“I want to talk about what she’s been up to this season. I think a lot of people take it for granted. She hasn’t been able to go home since February. That’s crazy. I mean, she’s getting back on the road. She worked “She won five titles and stayed number one. I mean this girl is everything any gamer wants to be.
“Honestly, I could do this for another 20 minutes. She’s one of my favorite people, so I always try to take advantage of the moment when I hug her.”
Barty herself showed real grace in defeat, admitting that it didn’t hurt so much to lose to Rogers because she was a good person.
“It sucks in tennis that there is a winner and a loser every day, but sometimes you don’t mind losing to certain people,” said Barty.
“I think Shelby is certainly one of them for me in terms of her personality and character.
“The last six months have been a roller coaster ride. I think back to the very first match I played on the trip. I was 5-2 behind in the third set of the first round in Miami. Tennis has a fun way of the night. ” Things off, right? “
An 18-year-old sensation in the form of Emma Raducanu is now awaiting Rogers in a fourth-round duel early next week, with the qualifier looking to continue her own impressive US Open run.
Barty has never won a US Open singles title. Her best performance in the competition was the fourth round in 2018 and 2019.
However, the 25-year-old achieved double success in the tournament. In 2018 she won the title with CoCo Vandeweghe.
Barty won her first Wimbledon title in July of this year and also won a bronze medal in mixed doubles at the recent Olympic Games in Tokyo.
The Australian announced in July that her Wimbledon success was all the more special considering that she is fit for the tournament in time. Because of a hip injury, she had to retire from the French Open in May.
“They held a lot of cards close to their chest and didn’t tell me much about the odds, didn’t tell me a lot of information they’d gotten from other specialists,” said Barty. “I think they didn’t tell me that it just proved how exposed we were to the adversity. There weren’t many radiologists in Australia who saw my injury. In a way, it was a two month injury.
“To be able to play here at Wimbledon was a miracle.
“I think it was amazing to play through this event now without pain. Certainly it looked a lot less likely now than I had statistically seen. I think it was an incredible month.”
The search for planets outside of our solar system (extrasolar planets) has increased by leaps and bounds over the past decade. A total of 4,514 exoplanets in 3,346 planetary systems have been confirmed, and a further 7,721 candidates are awaiting confirmation. Currently, astrobiologists are primarily focused on the “low-hanging fruit” approach, which looks for exoplanets that are similar in size, mass, and atmospheric composition to Earth (also known as “Earth-like”).
However, astrobiologists are also interested in finding examples of “exotic life” that arose under conditions that are not “Earth-like”. For example, a team of astronomers from Cambridge University recently carried out a study that showed how life could arise on ocean-covered planets with hydrogen-rich atmospheres (also known as “hycean” planets). These results could have a significant impact on exoplanet studies and the field of astrobiology.
The research was carried out by Dr. Nikku Madhusudhan, an astrophysics and exoplanetary science reader from the Institute of Astronomy (IoA) at Cambridge University. He was graduated from Ph.D. Astrophysics student Anjali Piette (Dr. Madhusudhan is her supervisor) and IoA member Dr. Savvas Constantinou. The study describing its results, entitled Habitability and Biosignatures of Hycean Worlds, recently appeared in the Astrophysical Journal.
An artist’s idea of how common exoplanets are in the Milky Way. Image source: Wikipedia
Life on small ice giants?
Of all exoplanets discovered in the last 30 years, the vast majority were either predominantly rock planets with multiple Earth masses (“super-earths”) or ice giants with a hydrogen-rich atmosphere (“mini-neptunes”) or somewhere in between. While super-earths make up about 30% (1,383) of all exoplanets discovered so far, mini-Neptunes are the most numerous with 34% (1,531).
Most mini-Neptunes are over 1.7 and 3.9 times the size of Earth and are believed to have interiors made up of ice, rocks, and oceans with volatile elements. Previous studies of such planets have shown that the pressure and temperature conditions under their hydrogen-rich atmospheres are too great to allow life. However, in an earlier study, Nikku Madhusudhan and his team found that these planets can support life under certain conditions.
In particular, they examined the exoplanet K2-18b, a mini-Neptune that was the focus of attention in 2019 when two different teams reported evidence of water vapor in its hydrogen-rich atmosphere. The results of this study led Dr. Madhusudhan and his team to study the full spectrum of planetary and stellar properties that would make it possible to make mini-Neptune potentially habitable.
This led them to identify a new class of planets that they named “Hycean,” which is a combination of the words “hydrogen” and “ocean”. Like the so-called “water worlds”, the worlds of the Hycea would be covered by oceans all over the world, but would have atmospheres dominated by hydrogen (in line with gas giants). The presence of this atmospheric hydrogen would enable a greenhouse effect that would help keep the surface oceans fluid.
Artist’s impression of K2-18b. Photo credit: Amanda Smith
properties
Planets falling into this classification would be about 2.6 times the diameter of the Earth and have atmospheric temperatures of up to 200 ° C (392 ° F), depending on the nature of their host star and the proximity of the planet to it. This is akin to what scientists thought the Earth was billions of years ago when the first unicellular microbial organisms appeared.
Like Dr. Madhusudhan summarized in a recent University of Cambridge press release, these results could mean that there is a class of exoplanets more abundant than “Earth-like” planets that support life, making them much easier for astrobiologists to find :
“Hycea planets open a whole new avenue in our search for life elsewhere. Essentially, in our search for these various molecular signatures, we have focused on Earth-like planets, which is a reasonable place to start. But we believe that Hycea planets offer a better chance of finding multiple traces of biosignatures. “
In addition, the team identified several top-rated Hycean candidates for follow-up in their study. Many of these are larger and hotter than Earth, but can still be covered in large oceans with conditions that could support microbial life. This life would likely be concentrated in extreme environments such as hydrothermal at the ocean-mantle boundary, similar to what has been observed here on Earth.
This type of exoplanet could include a subclass of tidal-locked “dark hycean” planets where habitable conditions exist only on their permanent night sides. The side facing the planet’s parent star would be too hot to hold water in liquid form indefinitely and transfer heat to the dark side through oceanic and atmospheric convection. There is also the possibility of “cold Hycean” worlds that receive little radiation from their stars and have icy shells.
Artist’s impression of an “eyeball” planet, a water world in which the side facing the sun can support an ocean with liquid water. Picture credits and copyright: eburacum45 / DeviantArt
Implications for Astrobiology
Planets of this size are the most common among the known exoplanet population, although they have not been studied in nearly as much detail as super-earths. But what they have in common means that some of the most promising places to look for life elsewhere in the galaxy may be hidden within sight. In addition, these planets allow for a much wider circumolar habitable zone than Earth-like planets.
To locate these exoplanets among the statistically significant super-earth and mini-Neptune populations, one would not simply have to determine their size. Other aspects such as mass, temperature, and atmospheric properties must also be investigated before a candidate can be safely called a Hycean. But most of all, astronomers need to take a close look at these potential Hyceans to see if there is any evidence of biosignatures.
“It’s exciting that habitable conditions can exist on planets so different from Earth,” said Anjali Piette. Also exciting is the fact that the potential Hycea biosignatures that Dr. Madhusudhan and his team have identified it will be easier to spot with spectroscopic observations. Their larger sizes, higher temperatures, and hydrogen-rich atmospheres mean that all atmospheric signatures are much more detectable than those of Earth-like planets. Madhusudhan said:
“Recognizing biosignatures would change our understanding of life in the universe. We have to be open about where we expect life and what form it could take, since nature often surprises us in unimaginable ways. “
Other possible biosignatures are organic compounds such as methyl chloride and dimethyl sulfide, which are less common on Earth but could be indicators of life on planets with hydrogen-rich atmospheres and low levels of oxygen or ozone. Again, this is in line with the “low hanging fruit” approach, in which we look for biomarkers that are required for or produced by life as we know it.
When next generation telescopes become available in the near future, the wide range of potential Hycea worlds the Cambridge team has prepared will be an excellent opportunity for follow-up observation. In addition, by cosmic standards, these planets are all relatively close and orbit M (red dwarf) -type stars that are 35 to 150 light-years from the solar system. There are already plans to study K2-18b (the most promising candidate) with the next generation James Webb Space Telescope (JWST).
When JWST kicks off in November (or early December) this year, astronomers will be able to conduct direct imaging studies of exoplanets in the near to mid-infrared and extract spectra directly from their atmosphere. The Nancy Grace Roman Space Telescope (RST) will follow in 2025 and will also perform direct imaging studies with its advanced system of optics, coronographs and spectrometers.
These results help illustrate how exoplanet research has grown and changed over the past few years. With thousands of confirmed exoplanets now available for study, the process has evolved from discovery to characterization. With improved tools and methods, astronomers can constrain the planetary environments more.
In the midst of it all, scientists can test their theories about the conditions under which life could exist in our cosmos. After all, the point is not just to find “life as we know it”, but as it exists in all its diversity and splendor. While we are now just looking for the low-hanging fruit, a day may come when we can climb the tree of life and find out which exotic fruit grows farthest from the earth.
Further reading: University of Cambridge, The Astrophysical Journal
In a recent interview with @entertainmenttonight, Dog The Bounty Hunter addressed several allegations, including allegedly homophobic and racist.
In the clip above, Dog explains that he previously used the racial slur because “the brothers” gave him a passport. As he spoke, he even stated that he had a passport “like Eminem”.
I’ve never been a racist. I’m 33.5 percent Apache. But I got an Achilles heel over 15 years ago for using the wrong word, ”Dog told ET. According to the publication, Chapman used racial slur more than six times during the call.
Dog added that he “believed I had a passport in the black trunk to use, much like Eminem did.”
Dog continued, “I had just been released from prison in 1979 after spending 18 months in Texas, and it was probably three-quarters of the black tribe. So that was a word we used back and forth, maybe as a compliment, ”he said. “My passport expired because I used it, but nobody told me that.”
Dog went on to say that he had many black friends and the word was used as a “compliment”.
Dog was also asked about his daughter who claimed he was homophobic. He said, “I have three men on my team who are gay. My daughter is gay, baby Lyssa. I don’t understand why anyone would ever say that. “
The host stated, “Remember, being close doesn’t mean you are not racist or homophobic.”
“Would I die for a gay man or a black man? I would give my life, ”said Dog.
