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Behold, the closest-ever photo of a coronal streamer
It was captured by the Parker Solar Probe, which is currently studying the star.
- NASA's Parker Solar Probe is currently traveling closer to the sun than any other spacecraft before it.
- The probe is recording data on the star to help scientists learn more about the star and its volatile nature.
- Also this week, NASA released the first images of its Mars InSight lander taken from space.
NASA's Parker Solar Probe has come closer to the sun than any human spacecraft before it, managing to enter the star's atmosphere to record data for the ambitious mission.
On November 8, the probe soared within about 15 million miles of the sun's surface. To illustrate how close that is, NASA researchers wrote: "If Earth was at one end of a yard-stick and the Sun on the other, Parker Solar Probe will make it to within four inches of the solar surface."
During the encounter, the probe's wide-field imager snapped the closest-ever photo of the sun emitting solar material, in an event known as a coronal streamer.
These events usually occur over regions undergoing increased solar activity, and this one appeared over the east limb of the sun and includes at least two visible rays. Jupiter, the bright spot toward the center of the photo, is also visible in the background.
The photo was shared at a meeting of the American Geophysical Union earlier this week.
"Heliophysicists have been waiting more than 60 years for a mission like this to be possible," said Nicola Fox, director of the Heliophysics Division at NASA Headquarters in Washington. Heliophysics is the study of the Sun and how it affects space near Earth, around other worlds and throughout the solar system. "The solar mysteries we want to solve are waiting in the corona."
What the Parker probe mission hopes to accomplish
The Parker Solar Probe is on an exploratory mission that could yield surprising findings for scientists, namely because no one's quite sure what exactly happens when a spacecraft gets so close to the sun. NASA hopes the mission will address three key questions:
"First: How is the sun's outer atmosphere, the corona, heated to temperatures about 300 times higher than the visible surface below?" NASA wrote in a blog post. "Second — how is the solar wind accelerated so quickly to the high speeds we observe? And finally, how do some of the sun's most energetic particles rocket away from the sun at more than half the speed of light?"
To answer these questions, the Parker probe must match the speed of the sun's rotation so it can hover over areas of interest, meaning it must fly faster than 213,000 miles per hour. Learning more about the star is important, given its tremendous influence on our planet and those in our solar system. NASA writes:
"The solar wind, its outflow of material, fills up the inner part of our solar system, creating a bubble that envelops the planets and extends far past the orbit of Neptune. Embedded in its energized particles and solar material, the solar wind carries with it the Sun's magnetic field. Additional one-off eruptions of solar material called coronal mass ejections also carry this solar magnetic field — and in both cases, this magnetized material can interact with Earth's natural magnetic field and cause geomagnetic storms. Such storms can trigger the aurora or even power outages, and other types of solar activity can cause communications problems, disrupt satellite electronics and even endanger astronauts — especially beyond the protective bubble of Earth's magnetic field."
NASA also releases first images of Mars InSight lander taken from space
This week, NASA published the first images taken of its Mars InSight lander, which touched down on the red planet in November and is designed to help scientists learn more about the formation of rocky planets. The images were taken from HiRISE, a camera onboard NASA's Mars Reconnaissance Orbiter (MRO).
- A 32,000 megapixel space camera is about to go online - Big Think ›
- Parker Solar Probe: Why it's NASA's most exciting mission - Big Think ›
- UAE's Hope Probe has transmitted its first image of Mars - Big Think ›
All this from a wad of gum?
- Researchers recently uncovered a piece of chewed-on birch pitch in an archaeological dig in Denmark.
- Conducting a genetic analysis of the material left in the birch pitch offered a plethora of insights into the individual who last chewed it.
- The gum-chewer has been dubbed Lola. She lived 5,700 years ago; and she had dark skin, dark hair, and blue eyes.
Five thousand and seven hundred years ago, "Lola" — a blue-eyed woman with dark skin and hair — was chewing on a piece of pitch derived from heating birch bark. Then, this women spit her chewing gum out into the mud on an island in Denmark that we call Syltholm today, where it was unearthed by archaeologists thousands of years later. A genetic analysis of the chewing gum has provided us with a wealth of information on this nearly six-thousand-year-old Violet Beauregarde.
This represents the first time that the human genome has been extracted from material such as this. "It is amazing to have gotten a complete ancient human genome from anything other than bone," said lead researcher Hannes Schroeder in a statement.
"What is more," he added, "we also retrieved DNA from oral microbes and several important human pathogens, which makes this a very valuable source of ancient DNA, especially for time periods where we have no human remains."
In the pitch, researchers identified the DNA of the Epstein-Barr virus, which infects about 90 percent of adults. They also found DNA belonging to hazelnuts and mallards, which were likely the most recent meal that Lola had eaten before spitting out her chewing gum.
Insights into ancient peoples
The birch pitch was found on the island of Lolland (the inspiration for Lola's name) at a site called Syltholm. "Syltholm is completely unique," said Theis Jensen, who worked on the study for his PhD. "Almost everything is sealed in mud, which means that the preservation of organic remains is absolutely phenomenal.
"It is the biggest Stone Age site in Denmark and the archaeological finds suggest that the people who occupied the site were heavily exploiting wild resources well into the Neolithic, which is the period when farming and domesticated animals were first introduced into southern Scandinavia."
Since Lola's genome doesn't show any of the markers associated with the agricultural populations that had begun to appear in this region around her time, she provides evidence for a growing idea that hunter-gatherers persisted alongside agricultural communities in northern Europe longer than previously thought.
Her genome supports additional theories on northern European peoples. For example, her dark skin bolsters the idea that northern populations only recently acquired their light-skinned adaptation to the low sunlight in the winter months. She was also lactose intolerant, which researchers believe was the norm for most humans prior to the agricultural revolution. Most mammals lose their tolerance for lactose once they've weaned off of their mother's milk, but once humans began keeping cows, goats, and other dairy animals, their tolerance for lactose persisted into adulthood. As a descendent of hunter-gatherers, Lola wouldn't have needed this adaptation.
A hardworking piece of gum
A photo of the birch pitch used as chewing gum.
These findings are encouraging for researchers focusing on ancient peoples from this part of the world. Before this study, ancient genomes were really only ever recovered from human remains, but now, scientists have another tool in their kit. Birch pitch is commonly found in archaeological sites, often with tooth imprints.
Ancient peoples used and chewed on birch pitch for a variety of reasons. It was commonly heated up to make it pliable, enabling it to be molded as an adhesive or hafting agent before it settled. Chewing the pitch may have kept it pliable as it cooled down. It also contains a natural antiseptic, and so chewing birch pitch may have been a folk medicine for dental issues. And, considering that we chew gum today for no other reason than to pass the time, it may be that ancient peoples chewed pitch for fun.
Whatever their reasons, chewed and discarded pieces of birch pitch offer us the mind-boggling option of learning what someone several thousands of years ago ate for lunch, or what the color of their hair was, their health, where their ancestors came from, and more. It's an unlikely treasure trove of information to be found in a mere piece of gum.
A study finds that baby mammals dream about the world they are about to experience to prepare their senses.
- Researchers find that babies of mammals dream about the world they are entering.
- The study focused on neonatal waves in mice before they first opened their eyes.
- Scientists believe human babies also prime their visual motion detection before birth.
Imagine opening your eyes for the first time as a brand new baby. The world is so mysterious, full of obstacles and strange shapes. And yet it does not take babies all that long to get their bearings, to latch on to their parents, and to start interacting. How do they do this so quickly? A new study published in Science proposes that babies of mammals dream about the world they are about to enter before being born, developing important skills.
The team, led by professor Michael Crair, who specializes in neuroscience, ophthalmology, and visual science, wanted to understand why when mammals are born, they are already somewhat prepared to interact with the world.
"At eye opening, mammals are capable of pretty sophisticated behavior," said Craig, "But how do the circuits form that allow us to perceive motion and navigate the world? It turns out we are born capable of many of these behaviors, at least in rudimentary form."
Unusual retinal activity
The scientists observed waves of activity radiating from the retinas of newborn mice before their eyes first open. Imaging shows that soon after birth, this activity disappears. In its place matures a network of neural transmissions that carries visual stimuli to the brain, as explained by a Yale press release. Once it reaches the brain, the information is encoded for storage.
What's particularly unusual about this neonatal activity is that it demonstrates a pattern that would happen if the animal was moving forward in its environment. As the researchers write in the study, "Spontaneous waves of retinal activity flow in the same pattern as would be produced days later by actual movement through the environment."
Crair explained that this "dream-like activity" makes sense from an evolutionary standpoint, as it helps the mouse get ready for what will happen to it after it opens its eyes. It allows the animal to "respond immediately to environmental threats," Crair shared.
What is creating the waves?
The scientists also probed what is responsible for creating the retinal waves that mimic forward motion. They turned on and off the functionality of starburst amacrine cells — retinal cells that release neurotransmitters — and discovered that blocking them stopped the retinal waves from flowing, which hindered the mouse from developing the ability to react to visual motion upon birth. These cells are also important to an adult mouse, affecting how it reacts to environmental stimuli.
Graphic showing the origin and functionality of directional retinal waves.Michael C. Crair et al, Science, 2021.
What about human babies?
While the study focused on mice, human babies also seem to be able to identify objects and motion right after birth. This suggests the presence of a similar phenomenon in babies before they are born.
"These brain circuits are self-organized at birth and some of the early teaching is already done," Crair stated. "It's like dreaming about what you are going to see before you even open your eyes."
The non-contact technique could someday be used to lift much heavier objects — maybe even humans.
- Since the 1980s, researchers have been using sound waves to move matter through a technique called acoustic trapping.
- Acoustic trapping devices move bits of matter by emitting strategically designed sound waves, which interact in such a way that the matter becomes "trapped" in areas of particular velocity and pressure.
- Acoustic and optical trapping devices are already used in various fields, including medicine, nanotechnology, and biological research.
Sound can have powerful effects on matter. After all, sound strikes our world in waves — vibrations of air molecules that bounce off of, get absorbed by, or pass through matter around us. Sound waves from a trained opera singer can shatter a wine glass. From a jet, they can collapse a stone wall. But sound can also be harnessed for delicate interactions with matter.
Since the 1980s, researchers have been using sound to move matter through a phenomenon called acoustic trapping. The method is based on the fact that sound waves produce an acoustic radiation force.
"When an acoustic wave interacts with a particle, it exerts both an oscillatory force and a much smaller steady-state 'radiation' force," wrote the American Physical Society. "This latter force is the one used for trapping and manipulation. Radiation forces are generated by the scattering of a traveling sound wave, or by energy gradients within the sound field."
When tiny particles encounter this radiation, they tend to be drawn toward regions of certain pressure and velocity within the sound field. Researchers can exploit this tendency by engineering sound waves that "trap" — or suspend — tiny particles in the air. Devices that do this are often called "acoustic tweezers."
Building a better tweezer
A study recently published in the Japanese Journal of Applied Physics describes how researchers created a new type of acoustic tweezer that was able to lift a small polystyrene ball into the air.
Tweezers of Sound: Acoustic Manipulation off a Reflective Surface youtu.be
It is not the first example of a successful "acoustic tweezer" device, but the new method is likely the first to overcome a common problem in acoustic trapping: sound waves bouncing off reflective surfaces, which disrupts acoustic traps.
To minimize the problems of reflectivity, the team behind the recent study configured ultrasonic transducers such that the sound waves that they produce overlap in a strategic way that is able to lift a small bit of polystyrene from a reflective surface. By changing how the transducers emit sound waves, the team can move the acoustic trap through space, which moves the bit of matter.
Move, but don't touch
So far, the device is only able to move millimeter-sized pieces of matter with varying degrees of success. "When we move a particle, it sometimes scatters away," the team noted. Still, improved acoustic trapping and other no-contact lifting technologies — like optical tweezers, commonly used in medicine — could prove useful in many future applications, including cell separation, nanotechnologies, and biological research.
Could future acoustic-trapping devices lift large and heavy objects, maybe even humans? It seems possible. In 2018, researchers from the University of Bristol managed to acoustically trap particles whose diameters were larger than the sound wavelength, which was a breakthrough because it surpassed "the classical Rayleigh scattering limit that has previously restricted stable acoustic particle trapping," the researchers wrote in their study.
In other words, the technique — which involved suspending matter in tornado-like acoustic traps — showed that it is possible to scale up acoustic trapping.
"Acoustic tractor beams have huge potential in many applications," Bruce Drinkwater, co-author of the 2018 study, said in a statement. "I'm particularly excited by the idea of contactless production lines where delicate objects are assembled without touching them."