CNN reports: A 70-foot rocket, riding beneath the wing of a retrofitted Boeing 747 aircraft, detached from the plane and fired itself into Earth's orbit on Sunday — marking the first successful launch for the California-based rocket startup Virgin Orbit.

Virgin Orbit's 747, nicknamed Cosmic Girl, took off from California around 10:30 am PT with the rocket, called LauncherOne, nestled beneath the plane's left wing. The aircraft flew out over the Pacific Ocean before the rocket was released, freeing LauncherOne and allowing it to power up its rocket motor and propel itself to more than 17,000 miles per hour, fast enough to begin orbiting the Earth... The rocket flew a group of tiny satellites on behalf of NASA's Educational Launch of Nanosatellites, or ELaNa, program, which allows high school and college students to design and assemble small satellites that NASA then pays to launch into space... About four hours after takeoff on Saturday, Virgin Orbit confirmed in a tweet that all the satellites were "successfully deployed into our target orbit."

The successful mission makes Virgin Orbit only the third so-called "New Space" company — startups hoping to overhaul the traditional industry with innovative technologies — to reach orbit, after SpaceX and Rocket Lab. The success also paves the way for Virgin Orbit to begin launching satellites for a host of customers that it already has lined up, including NASA, the military and private-sector companies that use satellites for commercial purposes.
Virgin Orbit shared a 57-second video on Twitter showing the moment their rocket was released and then launched, saying the event went exactly as planned.

"To say we're thrilled would be a massive understatement, but 240 characters couldn't do it justice anyway."

"SpaceX's attempt to reduce the reflectivity of Starlink satellites is working, but not to the degree required by astronomers," reports Gizmodo: Starlink satellites with an anti-reflective coating are half as bright as the standard version, according to research published in The Astrophysical Journal. It's an improvement, but still not good enough, according to the team, led by astronomer Takashi Horiuchi from the National Astronomical Observatory in Japan. These "DarkSats," as they're called, also continue to cause problems at other wavelengths of light [and] were included in a batch of satellites launched by SpaceX on January 7, 2020. The new study aimed to evaluate the effectiveness of that dark coating...

The scientists found that the "albedo of DarkSat is about a half of that of STARLINK-1113," as they wrote in their paper. That's a decent improvement in the visual spectrum, but still not great. What's more, problems persist at other wavelengths. "The darkening paint on DarkSat certainly halves reflection of sunlight compared to the ordinary Starlink satellites, but [the constellation's] negative impact on astronomical observations still remains," Horiuchi told Physics World. He said the mitigating effect is "good in the UV/optical region" of the spectrum, but "the black coating raises the surface temperature of DarkSat and affects intermediate infrared observations."

A third version of Starlink is supposed to be even dimmer. Called "VisorSats," they feature a sun visor that will "dim the satellites once they reach their operational altitude," according to Sky and Telescope. SpaceX launched some VisorSats last year, but the degree to which their albedo is lessened compared to the original version is still not known, or if these versions will exhibit elevated surface temperatures.

Horiuchi told Physics World that SpaceX should seriously consider lifting the altitude of the Starlink constellation to further reduce the brightness of these objects.
. The article ends with a quote from an astronomer at Harvard-Smithsonian Center for Astrophysics and an expert on satellites. He'd told Gizmodo's reporter back in January of 2020 that "SpaceX is making a good-faith effort to fix the problem," and that he believes the company "can get the satellites fainter than what the naked eye can see."

"NASA declared the Mars digger dead Thursday after failing to burrow deep into the red planet to take its temperature," reports the Associated Press: Scientists in Germany spent two years trying to get their heat probe, dubbed the mole, to drill into the Martian crust. But the 16-inch-long (40-centimeter) device that is part of NASA's InSight lander couldn't gain enough friction in the red dirt. It was supposed to bury 16 feet (5 meters) into Mars, but only drilled down a couple of feet (about a half meter). Following one last unsuccessful attempt to hammer itself down over the weekend with 500 strokes, the team called it quits.

"We've given it everything we've got, but Mars and our heroic mole remain incompatible," said the German Space Agency's Tilman Spohn, the lead scientist for the experiment...

InSight's French seismometer, meanwhile, has recorded nearly 500 Marsquakes, while the lander's weather station is providing daily reports.

"NASA's rocket charged with taking the agency back to the moon fired its four main engines Saturday afternoon, but the test in Mississippi was cut short after a malfunction caused an automatic abort," reports Florida Today...

"We did get an MCF on engine four," a control room member said less than a minute into the test fire, using an initialism that stands for "major component malfunction...." The engines fired for 12 more seconds after the exchange before an automatic shutdown was called. The test was meant to last eight minutes — the full duration needed for the booster during its Artemis program liftoff — but only ran less than two minutes.

Prime contractor Boeing previously said the test would need to run at least 250 seconds, or more than four minutes, for teams to gather enough data to move forward with transport to Kennedy Space Center and launch sometime before the end of the year. An exact plan moving forward, which could mean a second test and delay before transport to Florida, had not yet been released by Saturday evening.
Or, as the Guardian reports, "It was unclear whether Boeing and Nasa would have to repeat the test, a prospect that could push the debut launch into 2022."

In a press conference tonight, a NASA official specifically addressed the question of whether or not a launch this year was still feasible. "I think it's still too early to tell. I think as we figure out what went wrong, we're going to know what the future holds. And right now we just don't know...

"Not everything went according to script today, but we got a lot of great data, a lot of great information. I have absolutely total confidence in the team to figure out what the anomaly was, figure out how to fix it, and then get after it again... Depending on what we learn, we might not have to do it again."

They added that there was no sign of engine damage, and emphasized to reporters another way to view the significance of this afternoon's event. "A rocket capable of taking humans to the moon, was firing, all four engines at the same time." And they also stressed that this afternoon's result was not a failure -- but a test. "When you test, you learn things..."

"We're going to make adjustments, and we're going to fly to the moon. That's what the Artemis program is all about, that's what NASA is all about, and that's what America is all about. We didn't get everything we wanted, and yeah, we're going to have to make adjustments. But this was a test, and this is why we test.

"If you're expecting perfection on a first test, then you've never tested before."

"The date is set," NASA had tweeted Friday, thanking its partners Boeing Space and Aerojet Rocketdyne for Saturday's "hot fire" test of the SLS's core stage.

"One of NASA's main goals for 2021 is to launch Artemis I, an uncrewed moon mission meant to show the Orion spacecraft and Space Launch System rocket can safely send humans to our lunar neighbor," reported CNET. "But first, NASA plans to make some noise with a fiery SLS test on Saturday."

Below is the original report that schwit1 had shared from Space.com: It's a critical test for NASA and the final step in the agency's "Green Run" series of tests to ensure the SLS rocket is ready for its first launch... In the upcoming hot-fire engine test, engineers will load the Boeing-built SLS core booster with over 700,000 gallons of cryogenic (that's really cold) propellant into the rocket's fuel tanks and light all four of its RS-25 engines at once. The engines will fire for 485 seconds (a little over 8 minutes) and generate a whopping 1.6 million pounds of thrust throughout the test...

Following the success of this hot fire test and subsequent uncrewed missions to the moon, "the next key step in returning astronauts to the moon and eventually going on to Mars," Jeff Zotti, the RS-25 program director at Aerojet Rocketdyne said during the news conference. NASA's SLS program manager John Honeycutt agreed.

"This powerful rocket is going to put us in a position to be ready to support the agency in the country's deep space mission to the moon and beyond," he said.

"President-elect Joe Biden announced Friday that he has chosen a pioneer in mapping the human genome — the so-called 'book of life' — to be his chief science adviser," reports the Associated Press, "and is elevating the top science job to a Cabinet position." Biden nominated Eric Lander, founding director of the Broad Institute of MIT and Harvard, who was the lead author of the first paper announcing the details of the human genome, as director of Office of Science and Technology Policy and adviser on science. He is the first life scientist to have that job. His predecessor is a meteorologist.

Saying "science will always be at the forefront of my administration," Biden said he is boosting the science advisor post to Cabinet level, a first in White House history.... "Elevating (the science adviser) role to member in the President's Cabinet clearly signals the administration's intent to involve scientific expertise in every policy discussion," said Sudip Parikh, chief executive officer of the American Association for the Advancement of Science, the world's largest general scientific society.

An anonymous reader quotes a report from The Register: In 2010, Austin Sendek, then a physics student at UC Davis, created a petition seeking recognition for prefix "hella-" as an official International System of Units (SI) measurement representing 10^27. "Northern California is home to many influential research institutions, including the University of California, Davis, the University of California, Berkeley, Stanford University, and the Lawrence Livermore and Lawrence Berkeley National Laboratories," he argued. "However, science isn't all that sets Northern California apart from the rest of the world. The area is also the only region in the world currently practicing widespread usage of the English slang 'hella,' which typically means 'very,' or can refer to a large quantity (e.g. 'there are hella stars out tonight')."

To this day, the SI describes prefixes for quantities for up to 10^24. Those with that many bytes have a yottabyte. If you only have 10^21 bytes, you have a zettabyte. There's also exabyte (10^18), petabyte (10^15), terabyte (10^12), gigabyte(10^9), and so on. Support for "hella-" would allow you to talk about hellabytes of data, he argues, pointing out that this would make the number of atoms in 12 kg of carbon-12 would be simplified from 600 yottaatoms to 0.6 hellaatoms. Similarly, the sun (mass of 2.2 hellatons) would release energy at 0.3 hellawatts, rather than 300 yottawatts. [...] The soonest [a proposal for a "hella-" SI could be officially adopted] is in November 2022, at the quadrennial meeting of the International Bureau of Weights and Measures (BIPM)'s General Conference on Weight and Measures, where changes to the SI usually must be agreed upon. The report notes that Google customized its search engine in 2010 to let you convert "bytes to hellabytes." A year later, Wolfram Alpha added support for "hella-" calculations.

"Sendek said 'hellabyte' initially started as a joke with some college friends but became a more genuine concern as he looked into how measurements get defined and as his proposal garnered support," reports The Register. He believes it could be useful for astronomical measurements.

Underwater seagrass in coastal areas appear to trap plastic pollution in natural bundles of fiber known as "Neptune balls," researchers have found. The Guardian reports: With no help from humans, the swaying plants -- anchored to shallow seabeds -- may collect nearly 900 million plastic items in the Mediterranean alone every year, a study reported in the journal Scientific Reports said. "We show that plastic debris in the seafloor can be trapped in seagrass remains, eventually leaving the marine environment through beaching," lead author Anna Sanchez-Vidal, a marine biologist at the University of Barcelona, told AFP. This clean-up "represents a continuous purge of plastic debris out of the sea," she added.

To better understand the plastic bundling capabilities of seagrass, Sanchez-Vidal and her team studied a species found only in the Mediterranean sea, Posidonia oceanica. In 2018 and 2019, they counted the number of plastic particles found in seaballs that had washed up on four beaches in Mallorca, Spain, which has large seagrass meadows offshore. There was plastic debris in half of the loose seagrass leaf samples, up to 600 bits per kilogram of leaves.

Only 17% of the tighter bundled seagrass fibre known as Neptune balls contained plastic, but at a much higher density -- nearly 1,500 pieces per kilogram of seaball. Using estimates of seagrass fibre production in the Mediterranean, the researchers worked up an estimate of how much plastic might be filtered in the entire basin. The oval orbs -- the shape of a rugby ball -- form from the base of leaves that have been shredded by the action of ocean currents but remain attached to stems, called rhizomes. As they are slowly buried by sedimentation, the damaged leaf sheaths form stiff fibres that intertwine into a ball, collecting plastic in the process.

Facebook is harnessing the power of artificial intelligence to help doctors predict whether they will need more resources, such as extra oxygen to care for COVID-19 patients in hospitals. CNET reports: The social network said Friday it developed two AI models, one based on a single chest X-ray, and another from a series X-rays, that could help forecast if a patient infected by the coronavirus is likely to get worse. A third model predicts the amount of extra oxygen a COVID-19 patient might need. Facebook's AI models generally did a better job than a human when it came to forecasting up to four days in advance if a patient will need more intensive care resources.

Partnering with with New York University Langone Health's Predictive Analytics Unit and Department of Radiology, Facebook's AI research is another example of how tech companies are trying to help the health industry battle COVID-19. [...] Facebook's models rely on a technique in which AI learns on its own rather than depending on data labelled by humans, which can be a time-consuming process. The social network and NYU are publishing their research and open sourcing the AI models.

schwit1 shares a report from ScienceAlert: [S]cientists have just delivered their verdict on whether we'd be able to control a high-level computer super-intelligence. The answer? Almost definitely not. The catch is that controlling a super-intelligence far beyond human comprehension would require a simulation of that super-intelligence which we can analyze. But if we're unable to comprehend it, it's impossible to create such a simulation. Rules such as "cause no harm to humans" can't be set if we don't understand the kind of scenarios that an AI is going to come up with, suggest the authors of the new paper. Once a computer system is working on a level above the scope of our programmers, we can no longer set limits.

Part of the team's reasoning comes from the halting problem put forward by Alan Turing in 1936. The problem centers on knowing whether or not a computer program will reach a conclusion and answer (so it halts), or simply loop forever trying to find one. As Turing proved through some smart math, while we can know that for some specific programs, it's logically impossible to find a way that will allow us to know that for every potential program that could ever be written. That brings us back to AI, which in a super-intelligent state could feasibly hold every possible computer program in its memory at once. Any program written to stop AI harming humans and destroying the world, for example, may reach a conclusion (and halt) or not -- it's mathematically impossible for us to be absolutely sure either way, which means it's not containable.

The alternative to teaching AI some ethics and telling it not to destroy the world -- something which no algorithm can be absolutely certain of doing, the researchers say -- is to limit the capabilities of the super-intelligence. It could be cut off from parts of the internet or from certain networks, for example. The new study rejects this idea too, suggesting that it would limit the reach of the artificial intelligence -- the argument goes that if we're not going to use it to solve problems beyond the scope of humans, then why create it at all? If we are going to push ahead with artificial intelligence, we might not even know when a super-intelligence beyond our control arrives, such is its incomprehensibility. That means we need to start asking some serious questions about the directions we're going in.

MIT News: In the 1920s, German chemist Otto Warburg discovered that cancer cells don't metabolize sugar the same way that healthy cells usually do. Since then, scientists have tried to figure out why cancer cells use this alternative pathway, which is much less efficient. MIT biologists have now found a possible answer to this longstanding question. In a study appearing in Molecular Cell, they showed that this metabolic pathway, known as fermentation, helps cells to regenerate large quantities of a molecule called NAD+, which they need to synthesize DNA and other important molecules. Their findings also account for why other types of rapidly proliferating cells, such as immune cells, switch over to fermentation. "This has really been a hundred-year-old paradox that many people have tried to explain in different ways," says Matthew Vander Heiden, an associate professor of biology at MIT and associate director of MIT's Koch Institute for Integrative Cancer Research. "What we found is that under certain circumstances, cells need to do more of these electron transfer reactions, which require NAD+, in order to make molecules such as DNA." Vander Heiden is the senior author of the new study, and the lead authors are former MIT graduate student and postdoc Alba Luengo PhD '18 and graduate student Zhaoqi Li.

Fermentation is one way that cells can convert the energy found in sugar to ATP, a chemical that cells use to store energy for all of their needs. However, mammalian cells usually break down sugar using a process called aerobic respiration, which yields much more ATP. Cells typically switch over to fermentation only when they don't have enough oxygen available to perform aerobic respiration. Since Warburg's discovery, scientists have put forth many theories for why cancer cells switch to the inefficient fermentation pathway. Warburg originally proposed that cancer cells' mitochondria, where aerobic respiration occurs, might be damaged, but this turned out not to be the case. Other explanations have focused on the possible benefits of producing ATP in a different way, but none of these theories have gained widespread support. In this study, the MIT team decided to try to come up with a solution by asking what would happen if they suppressed cancer cells' ability to perform fermentation. To do that, they treated the cells with a drug that forces them to divert a molecule called pyruvate from the fermentation pathway into the aerobic respiration pathway.

An anonymous reader quotes a report from The Hill: A coalition of health and technology organizations are working to develop a digital COVID-19 vaccination passport to allow businesses, airlines and countries to check if people have received the vaccine. The Vaccination Credential Initiative, announced on Thursday, is formulating technology to confirm vaccinations in the likelihood that some governments will mandate people provide proof of their shots in order to enter the nation. The organization hopes the technology will allow people to "demonstrate their health status to safely return to travel, work, school and life while protecting their data privacy."

The initiative, which includes members like Microsoft, Oracle and U.S. nonprofit Mayo Clinic, is using the work from member Commons Project's international digital document that verifies a person has tested negative for COVID-19, the Financial Times reported. The Commons Project's technology, created in partnership with the Rockefeller Foundation, is being utilized by three major airline alliances. The coalition is reportedly in discussions with several governments to create a program requiring either negative tests or proof of vaccination to enter, Paul Meyer, the chief executive of The Commons Project, told the Times. The technology will need to allow patients to keep their data secure while being available in a digital wallet or a physical QR code for them to regulate who sees the information.

John Trumpian shares a report from Live Science: A man brewed a tea from "magic mushrooms" and injected the concoction into his veins; several days later, he ended up at the emergency department with the fungus growing in his blood. The man spent 22 days in the hospital, with eight of those days in the intensive care unit (ICU), where he received treatment for multisystem organ failure. Now released, he is still being treated with a long-term regimen of antibiotic and antifungal drugs, according to a description of the case published in the Journal of the Academy of Consultation-Liaison Psychiatry.

The case didn't reveal whether injecting shroom tea can cause persistent psychoactive effects, as sometimes seen when people ingest the fungus orally, the doctors wrote in the report. [...] By injecting shrooms into his bloodstream, the 30-year-old patient had hoped to relieve symptoms of bipolar disorder and opioid dependence, according to the report. His family members noted that he had recently stopped adhering to his prescribed bipolar medications and was "cycling between depressive and manic states."

An anonymous reader quotes a report from NBC News: Data released Thursday by the National Oceanic and Atmospheric Administration, or NOAA, showed that 2020 now ranks as the second-hottest year, with average temperatures hitting 58.77 degrees Fahrenheit -- a mere 0.04 degrees cooler than 2016, which holds the record. The Northern Hemisphere experienced its hottest year on record, surpassing the 20th century average by 2.3 degrees, according to NOAA. Oceans were also "exceptionally warm" last year, with record-high sea surface temperatures logged across parts of the Atlantic, Pacific and Indian oceans.

Above-average temperatures also shrank Arctic sea ice to near record lows, NOAA scientists said. Satellite observations revealed that Arctic sea ice in 2020 covered an average of 3.93 million square miles, tying 2016 for the smallest on record. Though NOAA has designated 2020 as the second-hottest year since record-keeping began in 1880, there are some discrepancies among other agencies that conduct similar measurements. A NASA analysis found that global average surface temperatures in 2020 tied with 2016, while the World Meteorological Organization still has 2016 in the lead. The discrepancies among these groups owe to subtle differences in how they account for data gaps over parts of the planet that lack reliable weather stations, such as in the polar regions or over wide swaths of the ocean. But experts say these small differences are inconsequential against the broader backdrop of global warming. The planet's seven warmest years on record have all been since 2014, according to NOAA, with 10 of the warmest years occurring since 2005.

AmiMoJo shares a report from 9to5Mac: When Apple revived MagSafe with the iPhone 12 lineup, one question brought up was how these latest devices with more magnets would interact with medical devices like pacemakers. Apple's official word was that iPhone 12/MagSafe wouldn't interfere more than previous iPhones. Now one of the first medical studies has been published by the Heart Rhythm Journal that saw a Medtronic pacemaker deactivated by holding an iPhone 12 near it (via MacMagazine. It doesn't sound like there is concrete evidence that iPhone 12 and MagSafe do pose a greater risk of increased interference but with this study out now, we may see more testing in the medical field to find out for sure. Of course it's not just iPhones or smartphones that can create interference issues, it can be any item that contains magnets strong enough create a problem.

As you'd expect, the short-term solution is to keep iPhones and other devices away from pacemakers and other similar medical devices. However, reported by Medical Xpress, Medtronic and others are likely looking to shift away from the reliance on magnets in future devices: "Unless companies like Medtronic get on board and move to smarter device configuration options, they will continue to butt heads with consumer devices -- and they will continue to lose. Smarter options don't have to be expensive; just look at your cheap IR TV remote or ultrasonic receiver-emitter pair. These devices simply work. They use an uncomplicated code to make sure there is no interference from all the other ambient sources that are invariably present. A couple of secure ultrasonic bits superimposed on your basic 40 khz carrier waves is all that is really needed. It is likely that companies like Medtronic are working on solutions like this; for example, a Medtronic programming head of some sort can be had on Ebay at the moment for a mere $34.99."

The higher a person's income, the more likely they were to protect themselves at the early stages of the Covid-19 pandemic in the United States, Johns Hopkins University economists find. From a report: When it comes to adopting behaviors including social distancing and mask wearing, the team detected a striking link to their financial well-being. People who made around $230,000 a year were as much as 54% more likely to increase these types of self-protective behaviors compared to people making about $13,000. The findings, that could contribute to more accurate predictions of how the disease will spread, appear in the latest Journal of Population Economics.

As part of a six-country survey, 1,000 people in the United States, from Texas, Florida, California and New York, were asked a series of questions in April 2020 to determine if and how their behavior had changed as Covid-19 cases were beginning to spike across the country. The resulting data includes information on income, gender and race along with unique variables relevant to the pandemic, such as work arrangements and housing quality. The team, which included economics graduate student Matthew Zahn, found that while almost everyone changed their behavior in some way to try to stay safe, people making the most money made the most changes. The highest earners were 13% more likely to change their behaviors, 32% more likely to increase social distancing and 30% more likely to increase hand washing and mask wearing. But the team found it was also much easier for people with more money to take extra safety measures. Higher-income individuals were more likely to report being able to work from home and more likely to have transitioned to telework instead of losing their job. The researchers found the ability to telework emerged as a huge predictor of whether someone would social distance. Compared to somebody who continued to work, people able to telework were 24% more likely to social distance.

Blue Origin launched its first mission of 2021, flying its New Shepard rocket in West Texas to a medium height of just over 350,000 feet. From a report: This is the first flight for this particular booster, and for the capsule it carried, which was equipped with a range of new passenger safety, control and comfort systems that Blue Origin was testing during flight for the first time. Also on board was a life-sized test dummy called 'Mannequin Skywalker' that recorded information during the flight and landing that the Blue Origin will now review. Based on the video stream and commentary from the company, this looks like a very successful test, including a takeoff, booster separation, controlled landing burn and touchdown -- and a parachute-aided landing back on terra firma for the crew capsule. The mission didn't carry any real passengers, although there were 50,000 postcards on board from school kids globally that have now officially been to space (past the Karman line) which will be returned to those students via Blue Origin's non-profit 'Club for the Future.'

The European Commission says it wants its newly proposed satellite mega-constellation to be offering some sort of initial service in 2024. The BBC reports: The first priority is to fill in gaps in broadband coverage where ground infrastructure cannot reach, but later it will power services such as self-driving cars. The project will in some ways mirror America's Starlink and the UK-Indian OneWeb networks. Its scope has yet to be fully defined. A consortium of aerospace and telecoms companies is doing that right now.

But EU Internal Market Commissioner Thierry Breton said he wanted to get going on the idea as soon as possible. "My objective is to go fast. And therefore it would be appropriate that the Commission puts forward this year a proposal to the European Parliament and the Council so we can move concretely," he told the 13th European Space Conference on Tuesday. "To be ready, we launched a few weeks ago a study on a secure space-based connectivity system. The selected consortium consisting of European satellite manufacturers, operators and service providers, telco operators and launch service providers will study the possible design and development of this project. This will provide insights on the technical dimension, but also the governance structure, the financing, the missions, the exact scope. I expect their first feedback in April this year."

British spacecraft could travel to Mars in half the time it now takes by using nuclear propulsion engines built by Rolls-Royce under a new deal with the UK Space Agency. From a report: The aerospace company hopes nuclear-powered engines could help astronauts make it to Mars in three to four months, twice as fast as the most powerful chemical engines, and unlock deeper space exploration in the decades to come. The partnership between Rolls-Royce and the UK Space Agency will bring together planetary scientists to explore how nuclear energy could be used to "revolutionise space travel," according to the government. Dr Graham Turnock, the chief executive of the UK Space Agency, said using nuclear power in space was "a gamechanging concept that could unlock future deep-space missions that take us to Mars and beyond."

An anonymous reader shares a report: While we might think of space as a vast sea of blackness, all we have to do is look up at night to see that it's punctuated by countless stars, galaxies and even a few planets visible to the naked eye. Scientists recently used data from NASA's New Horizons mission out beyond Pluto to measure just how dark the cosmic background really is. What they found has implications for what we thought we knew about the makeup of the entire universe. In short, space is so dark there can't be as many galaxies out there, adding their faint glow to the backdrop, as astronomers have previously estimated.

"It's an important number to know -- how many galaxies are there?" Marc Postman of the Space Telescope Science Institute said in a statement Tuesday. "We simply don't see the light from 2 trillion galaxies." That was the earlier estimate derived from Hubble Space Telescope observations, but a new study forthcoming in the Astrophysical Journal and co-authored by Postman suggests the total number of galaxies in the universe is probably in the hundreds of billions rather than the trillions. Interestingly, this is closer to an even earlier figure guessing there were around 200 billion galaxies. That was based on Hubble data from the 1990s.

Scientists in Brazil have downgraded the efficacy of a Chinese coronavirus vaccine that they hailed as a major triumph last week, diminishing hopes for a shot that could be quickly produced and easily distributed to help the developing world. From a report: Officials at the Butantan Institute in Sao Paulo said on Tuesday that a trial conducted in Brazil showed that the CoronaVac vaccine, manufactured by the Beijing-based company Sinovac, had an efficacy rate just over 50 percent. That rate, slightly above the benchmark that the World Health Organization has said would make a vaccine effective for general use, was far below the 78 percent level announced last week. The implications could be significant for a vaccine that is crucial to China's global health diplomacy. At least 10 countries have ordered more than 380 million doses of the Sinovac inoculation, CoronaVac, though regulatory agencies have yet to fully approve it.

A senior official in Hong Kong, a special administrative region of China that had already ordered CoronaVac, said on Wednesday that an advisory panel would strictly review the vaccine based on clinical trial data before it was rolled out there. "Those countries that have ordered the Chinese-made vaccines are probably going to question the usefulness of these vaccines," said Yanzhong Huang, a senior fellow for global health at the Council on Foreign Relations and an expert on health care in China. "Countries with opposition parties might use this to challenge the decision made by the incumbent government, and that will likely have domestic political implications in these countries," Mr. Huang said. Sinovac did not respond to multiple requests for comment.