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Astronomers Might Soon Have Many More Glimpses Into the Early Universe

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a bright disk with a jet extending

Quasars are active black holes at the centers of distant galaxies. (Credit: ESO/M. Kornmesser)

For decades, scientists have been on the hunt for brilliant galaxies in the distant universe. These quasars were first noticed for being spectacularly bright – some of the most energetic objects ever discovered. But astronomers think many of them – in fact, the vast majority from the early universe – may be in hiding, camouflaged behind much closer galaxies.

Because of their brightness, astronomers want to use quasars to probe the era of reionization. This is a time less than a billion years after the Big Bang, when the first generation of stars and then galaxies formed. Quasars are supermassive black holes in the centers of galaxies, actively gobbling material. They’re some of the few objects that can be seen from such a distance, which makes them some of the only glimpses we have of the early universe.

Often even quasars are often too dim to see from so long ago (and therefore so far away). But astronomers have a trick to see far away in the universe: gravitational lensing. This is where gravity from an object in between the observer and the quasar – such as a galaxy or galaxy cluster – bends the traveling light, magnifying its intensity. And given how far away these quasars are, quite literally most of the universe is between us and them. So there should be plenty of stuff in the way to magnify their light.

This means there should be many lensed quasars from this era to view, and yet the first was just discovered this year – and it was very nearly missed. But its discovery and near-miss offered another hint: That these sought-after distant light sources were hiding in plain sight all along.

How to Spot Quasars

Early quasars all appear somewhat similar, so astronomers know what colors the quasars should be. They select their targets accordingly before using better telescopes to confirm them and find out for sure whether they’ve found a quasar, or just a star or galaxy with quasar-like colors. 

Fabio Pacucci, an astronomer at Yale University, explains when this system works, and when it fails. He’s the lead author on a new paper about how many quasars astronomers may be missing, published in the Astrophysical Journal Letters on January 10. He was also a co-author on the study about the first early-universe lensed quasar finally discovered.

“This one barely made the cut-off as being identified,” Pacucci says, “because the lensing galaxy between us and the quasar affects the color.” Since the colors are blended, the quasar no longer looks like a quasar, so astronomers never bother looking any closer at such objects. He says that’s how so many quasars are escaping detection.

A compounding problem is that many lensed quasars appear so close to their lens that unless you use an instrument on the level of Hubble, most telescopes can’t distinguish them as separate objects. “It’s very likely that in previous surveys … this problem has been encountered lots of times,” Pacucci adds. And every time, the quasar was identified as a nearby galaxy, instead of as a quasar.

But hope isn’t lost. Pacucci says both problems can be overcome to reveal a wealth of distant quasars. Easiest is to simply change the selection criteria astronomers use to search for quasars, now that they know the quasars’ colors could be blended with closer galaxies.

Second, new telescopes like WFIRST, coming online within the next decade, will be able to look as precisely as Hubble, separating the quasar from its lens, but with a much wider field of view, so they can search for many of these quasars at once.

Pacucci and his colleagues estimate that the vast majority of lensed quasars from the beginnings of the universe are currently being missed. It will take more work, but by changing astronomers expectations for how these quasars appear, a treasure trove of targets from the early universe might be within reach.



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Pumped Milk Gives Infants Different Bacteria Than Breastfeeding, Study Says

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(Credit: Africa Studio/Shutterstock)

Mother’s milk provides sustenance for babies. Now researchers find pumped breast milk exposes newborns to more disease-causing bacteria than milk directly from the breast. The discovery suggests breastfeeding practices could shift the makeup of microorganisms in breast milk and infants’ digestive systems.

“We were surprised that the method of feeding was the most consistent factor associated with milk microbiota composition,” said Meghan Azad, a medical geneticist at the Children’s Hospital Research Institute of Manitoba in Canada, who led the new research.

Mighty Milk

Once considered sterile, researchers now know breast milk is full of bacteria. The microbes are thought to help set up infants’ digestive tracts with an ecosystem of microorganisms that will aid the growing human’s digestive and immune systems. Azad and her team were initially curious about this collection of bacteria in infants known as the infant gut microbiome. In an earlier study, they found breastfeeding affected babies’ gut bacteria the most. So, in the new research, the scientists probed the microbes in breast milk.

The researchers checked out the microbes in breast milk from nearly 400 nursing mothers and their three to four month old babies. The mommy-baby pairs are a part of a Canadian Healthy Infant Longitudinal Development birth cohort study known as the CHILD study, a long-term project looking to find the source of pediatric allergies. The researchers also looked at other elements — maternal age, smoking status and the microbes in babies mouths, to name a few — that could affect what bacteria are in breast milk.

Pumping Problem

The microbes in breast milk varied drastically between mothers, the researchers found, and both mom and baby mold the milk microbiome.

“Our results suggest that the infant’s oral bacteria are important in shaping the milk microbiota,” said Shirin Moossavi, a medical microbiology student in Azad’s lab, who authored the research.

But the biggest factor was whether babies received breast milk straight from the nipple or from a bottle. A family of bacteria that includes E. coli and salmonella were more abundant in pumped breast milk than direct breast milk, the researchers reported Wednesday in the journal Cell Host & Microbe.

“It is only in recent years that we have started to understand that there might be differences between direct nursing compared to feeding pumped milk,” Azad said.

“In the future, when we understand the mechanisms better, we might be able to provide recommendations about pump apparatus cleaning and milk storage to minimize the impact on the milk microbiota,” Moossavi added.

But no matter the delivery mode, “overall, breast milk is the best for the infant,” the researchers said.



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NASA Wants to Return to the Moon as Early as This Year

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NASA has big plans for returning to the moon, but private companies will do much of the work. (Credit: NASA)

In November, NASA tapped nine private spaceflight companies who will be allowed to bid on upcoming projects. Yesterday, they elaborated on what those projects would be during an industry forum. Starting as early as this year, NASA hopes to send commercial landers to the lunar surface as the first step toward returning to the moon, this time for good.

Long Lunar To-Do List

There’s a lot of work to be done before permanent or long-term lunar activities can begin. The first tasks will be to practice launching and landing on the moon, as well as answering questions about its surface. There’s plenty of technology NASA wants to see established on the ground before humans are sent back to the moon – and a lot of it is meant to stand in for future Mars settlement as well.

Some of that technology has to do with a recent buzzword among the space settlement community: in-situ resource utilization, or ISRU. This means using materials and resources already available on the moon and, one day, Mars, rather than carting all our resources with us, as has been standard for space missions. This most commonly means using solar power for energy. On the moon, it will also mean extracting water, which can be used for drinking or to power rockets. Both the hydrogen and oxygen that make up water are powerful fuel materials.

So commercial lunar partners will work on how to mine and recycle resources on the moon and make them available for future mission use. They will test habitation for future crewed missions. They’ll prove that they can collect materials from the lunar surface and return them to space or Earth. And they’ll establish communication networks between robots on the moon’s surface, way stations in lunar orbit, and mission control on Earth.

All these commercial endeavors would also need to integrate with NASA’s planned Lunar Gateway. This would be a space station in orbit around the moon that would serve as Grand Central Station for robotic or crewed missions to the lunar surface, or even for deep space missions. NASA hopes to open the Gateway by 2026, with the first power and propulsion elements entering orbit in 2022.



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Climate Change Hearings Signal Congress Is Willing to Address the Issue Again

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(credit: Roschetzky Photography/Shutterstock)

Climate change is real. It’s happening now. And it presents significant problems for the U.S. across multiple facets of society, according to a panel of climate and policy experts that testified before the House Science, Space and Technology Committee Wednesday in Washington, D.C.

The testimonials were part of the House Science Committee’s first full hearing of the 116th Congress and one of only a handful in the last eight years to address climate change. But that’s about to change. In her opening remarks, House Science Committee Chairwoman Eddie Bernice Johnson (D-TX) said Wednesday’s hearing will be the first of multiple hearings on climate change in the near future.

“Climate change is not just an environmental challenge,” said Robert Kopp, a climate scientist at Rutgers University in New Brunswick, New Jersey, during his testimony. “It’s an economic challenge, an infrastructure challenge, a public health challenge and a national security challenge.”

Carbon Cuts

For the most part, House representatives were in agreement with the panel that climate change is real and harming not only the environment but the economy and Americans. During the nearly two and half hours of questions that followed the researchers’ testimonies, representatives asked the scientists to identify priorities and sought their suggestions for solutions.

“Human emissions of CO2 must be brought as close to zero as possible with any continued emissions of CO2 balanced by human removal of carbon dioxide from the atmosphere,” said Kopp, who suggested expanding forests and using new, but little-tested technologies as a start. “The faster we reduce emissions, the less severe the effects and the lower the risk of unwelcome surprises,” he added.

Cities, states and a number of companies are already taking action by adopting emission reduction targets, but Kopp says these efforts need to grow dramatically and rapidly to effectively manage climate risk.

But Joseph Majkut, a policy expert with the Niskanen Center, a non-partisan think tank based in Washington, D.C., who also testified, acknowledged, “That’s a challenging thing to do.”

“To even get close, we’ll need significant innovation in low-carbon technology, finance and market design in order to be able to provide reliable, affordable and globally accessible low carbon energy,” Majkut said.

Majkut projected that to reach any temperature target, much less the 1.5 degrees C (2.7 degrees F) of warming goal set by the IPCC, would require carbon capture and storage of fossil fuels as well as carbon removal technologies in conjunction with renewable energy and storage solutions. He then advocated for research into alternatives to reducing global emissions, such as geoengineering technologies that would offset greenhouse gas production.

The scientists’ recommendations align with many facets of the Green New Deal Rep. Alexandria Ocasio-Cortex (D-NY) and Sen. Ed Markey (D-MA) recently proposed. The legislation calls for a massive policy shift that bolsters the U.S. economy and cuts greenhouse gas emissions to zero. Like the solutions Majkut outlined for the House Science Committee, the Green New Deal lists expanding and upgrading renewable energy sources, removing greenhouse gases from the atmosphere and increasing carbon storage as ways to achieve its goal.

Rep. Ralph Norman (R-SC) and others raised concerns about the cost of such an initiative, asking “If the Green New Deal were implemented immediately, wouldn’t it devastate our economy?” But, says Majkut, reducing CO2 associated with economic activity is “one of the cheapest elements” of the bill.

Adaptive Measures

The scientists testifying before the House also recommended prioritizing research into the ways society might adapt to climate change and called on federal support for studies of how climate change will affect communities, a research topic Kristie Ebi, an epidemiologist at the University of Washington in Seattle, is already looking into.

Ebi, another scientist to testify at the hearing, investigates how climate change affects human health. Researchers have discovered Americans are already suffering and dying from climate change and the impacts will likely only get worse.

“Risk from vector-borne diseases such as malaria, Dengue fever and Lyme disease are projected to increase with warming from 1.5 to 2 C (2.7 to 3.6 F) including potential shifts in their geographic range to areas previously unexposed to these diseases,” Ebi said. “Further, our healthcare infrastructure is vulnerable to extreme events with, for example, many hospitals and healthcare clinics located in coastal regions subject to flooding.”

Yet, there are achievable ways to alleviate the projected risks and costs associated with climate change’s impacts on communities, Ebi said, such as “developing early notification response plans for extreme heat … and incorporating climate projections into emergency preparedness and disaster risk management initiatives.”

“These steps can protect health now and provide a basis for effective adaptation to our future climate,” she added.

And if the world does not slow the rise of greenhouse gas emissions, Americans’ health and the U.S. economy will suffer because of impacts associated with mortality and the ability of people to work outdoors, scientists say. More extreme weather events will also affect human health and the economy.

“We know that in 2018, the losses due to extreme weather were roughly $160 billion just to the U.S.,” said Jennifer Francis, an atmospheric scientists at the Woods Hole Research Center in Falmouth, Massachusetts, during her testimony. “But what keeps me up at night is thinking about my own daughter and the world she will face if we do nothing.”



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