Voyager Probes Spot Previously Unknown Phenomenon in Deep Space

Artistic conception of a Voyager spacecraft.

Artistic conception of a Voyager spacecraft.
Image: NASA/JPL-Caltech

NASA’s Voyager spacecraft may be billions of miles away and over 40 years old, but they’re still making significant discoveries, as new research reveals.

A paper published today in the Astronomical Journal describes an entirely new form of electron burst, a discovery made possible by the intrepid Voyager probes. These bursts are happening in the interstellar medium, a region of space in which the density of matter is achingly thin. As the new paper points out, something funky is happening to cosmic ray electrons that are making their way through this remote area: They’re being reflected and boosted to extreme speeds by advancing shock waves produced by the Sun.

By itself, this process, in which shock waves push particles, is nothing new. What is new, however, is that these bursts of electrons are appearing far ahead of the advancing shock wave, and that it’s happening in a supposedly quiet region of space. The new paper was co-authored by astrophysicist Don Gurnett from Iowa University.

Launched in 1977, Voyager 1 and Voyager 2 have done tremendous work for king and country, and they’re still enabling meaningful scientific work after so many years. But instead of studying active volcanoes on Jupiter’s moon Io or taking glorious photos of Saturn’s rings, these probes are now studying the uncharted waters beyond the heliopause—the zone between the hot solar plasma and the cooler interstellar medium at the outer reaches of the solar system.

“This is analogous to seeing light reflected from the cloud of a far-away explosion, and then hearing the boom at a later time.”

Voyager 1 is currently 14.1 billion miles away, and Voyager 2 is 11.7 billion miles away (the probes were launched within 16 days of one another, but they were sent on different trajectories during their respective sojourns through the solar system). Voyager 1 crossed the heliopause boundary in 2012, and Voyager 2 did the same in 2018. They’re currently traveling through a region referred to as the very local interstellar medium (VLISM), according to the study. The Voyager probes are the most distant human-made objects ever.

Some may quibble about the term “interstellar medium” and claim that the Voyager probes are still technically inside the solar system, but Gurnett is adamant that the Voyager probes are indeed traveling through interstellar space, which literally means the “medium between the stars,” as he explained by phone. “We won that argument,” said Gurnett, “but of course I’m biased.” The pressure of gas at the location of the Voyager probes, he said, is equal to the pressure of gas we would expect to see in interstellar space. To him, that means the probes are inside the interstellar medium.

In 2012, Gurnett at his colleagues declared that Voyager 1 crossed into interstellar space, a claim confirmed by NASA the following year.

Years ago, before the NASA probes entered this region of space, “we thought

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Mars microbes may have been able to live deep below the planet’s surface

This processed image shows a sideways view of a water-carved channel on Mars.


ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO. 3D rendered and colored by Lujendra Ojha

Humanity is super-stoked about the idea of finding signs of ancient life on Mars. So much so we keep sending increasingly more advanced machines, like NASA’s Perseverance rover, to search for evidence. But we might need to take a much deeper look into the matter, a new study suggests. 

A research team led by Rutgers University planetary scientist Lujendra Ojha examined a perplexing problem when it comes to the long-ago habitability of Mars: the paradox of the faint young sun.

The sun wasn’t always the perky ball of heat and light we know today. “About 4 billion years ago, the sun was much fainter so the climate of early Mars should have been freezing,” Rutgers said in a statement on Wednesday. That’s a bit of mystery because we also see lots of signs of water in Mars’ past. 

Research in recent years has pointed to long-ago liquid water on the Martian surface and even the presence of wild megafloods

If it were warm and wet, Mars might have been habitable for microbial life. But how do we get meltwater with a faint young sun? The paper from Ojha and his colleagues, published in the journal Science Advances today, addresses this problem.

“I and my co-authors propose that the faint young sun paradox may be reconciled, at least partly, if Mars had high geothermal heat in its past,” Ojha said. This is a phenomenon seen on Earth where decaying elements produce heat that can melt ice sheets from below. If Mars experienced similar conditions, that could explain liquid water despite the faint sun.

The study shows that ancient Mars would have been ripe for this sort of heating action 4 billion years ago, but the planet’s surface wouldn’t have remained very friendly for liquid water thanks to a thin atmosphere and increasingly colder temperatures. “Therefore, life, if it ever originated on Mars, may have followed liquid water to progressively greater depths,” Rutgers said.

“At such depths, life could have been sustained by hydrothermal (heating) activity and rock-water reactions,” Ojha said. “So, the subsurface may represent the longest-lived habitable environment on Mars.”  

Our knowledge of Mars and its lineage of water has been expanding at a rapid clip. Recent studies have pointed to hidden ponds of briny water under the Martian polar ice

Rovers will continue to scour the Martian surface for hints of ancient life, but we may one day want to peer deeper under the planet’s skin to fully understand its history of habitability.

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Mars microbes may have been able to live deep below planet’s surface

This processed image shows a sideways view of a water-carved channel on Mars.


ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO. 3D rendered and colored by Lujendra Ojha

Humanity is super-stoked about the idea of finding signs of ancient life on Mars. So stoked we keep sending increasingly more advanced machines, like NASA’s Perseverance rover, to search for evidence. A new study suggests we might need to take a much deeper look into the matter. 

A research team led by Rutgers University planetary scientist Lujendra Ojha examined a perplexing problem when it comes to the long-ago habitability of Mars: the paradox of the faint young sun.

The sun wasn’t always the perky ball of heat and light we know today. “About 4 billion years ago, the sun was much fainter so the climate of early Mars should have been freezing,” Rutgers said in a statement on Wednesday. That’s a bit of mystery because we also see lots of signs of water in Mars’ past. 

Research in recent years has pointed to long-ago liquid water on the Martian surface and even the presence of wild megafloods

If it were warm and wet, Mars might have been habitable for microbial life. But how do we get meltwater with a faint young sun? The paper from Ojha and his colleagues, published in the journal Science Advances today, addresses this problem.

“I and my co-authors propose that the faint young sun paradox may be reconciled, at least partly, if Mars had high geothermal heat in its past,” Ojha said. This is a phenomenon seen on Earth where decaying elements produce heat that can melt ice sheets from below. If Mars experienced similar conditions, that could explain liquid water despite the faint sun.

The study shows that ancient Mars would have been ripe for this sort of heating action 4 billion years ago, but the planet’s surface wouldn’t have remained very friendly for liquid water thanks to a thin atmosphere and increasingly colder temperatures. “Therefore, life, if it ever originated on Mars, may have followed liquid water to progressively greater depths,” Rutgers said.

“At such depths, life could have been sustained by hydrothermal (heating) activity and rock-water reactions,” Ojha said. “So, the subsurface may represent the longest-lived habitable environment on Mars.”  

Our knowledge of Mars and its lineage of water has been expanding at a rapid clip. Recent studies have pointed to hidden ponds of briny water under the Martian polar ice

Rovers will continue to scour the Martian surface for hints of ancient life, but we may one day want to peer deeper under the planet’s skin to fully understand its history of habitability.

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Australian telescope maps deep space at record speed

MELBOURNE (Reuters) – A powerful new telescope in outback Australia has mapped vast areas of the universe in record-breaking time, revealing a million new galaxies and opening the way to new discoveries, the country’s national science agency said on Tuesday.

The A$188 million ($138 million) radio telescope, dubbed the Australian Square Kilometre Array Pathfinder (ASKAP), was able to map about three million galaxies in just 300 hours. Comparable surveys of the sky have taken as long as 10 years.

“It’s really a game changer,” said astronomer David McConnell, who led the Commonwealth Scientific and Industrial Research Organisation (CSIRO) study of the southern sky at the Murchison Radioastronomy Observatory in Western Australia.

What makes this telescope unique is its wide field of view, using receivers designed by CSIRO, which allow it to take panoramic pictures of the sky in sharper detail than before.

The telescope only needed to combine 903 images to map the sky, compared with other all-sky radio surveys that require tens of thousands of images.

“It is more sensitive than previous surveys that have covered the whole sky like this, so we do see more objects than have been seen in the past,” McConnell told Reuters.

Having a telescope that can survey the sky in a few weeks or months means the process can be repeated again and again in a relatively short space of time, allowing astronomers to systematically spot and track changes.

“Even with this first pass we’ve got right now, compared with previous images, we’ve already found some unusual objects,” McConnell said, including some unusual stars that undergo violent outbursts.

He said data gathered in this survey would allow astronomers to find out more about star formation and how galaxies and black holes evolve through statistical analyses.

The initial results were published on Tuesday in the Publications of the Astronomical Society of Australia.

($1 = 1.3580 Australian dollars)

Reporting by Sonali Paul; Editing by Lincoln Feast.

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Transportation of water into the deep Earth by Al-phase D

Transportation of water into the deep Earth by Al-phase D
(a) Shear velocity contrast between the Al-rich hydrous layer (including Al-phase D) and the dry mantle for two model compositions: hydrous pyrolite (h-pyrolite) and hydrous harzburgite (h-Harzburgite). (b) Hypothetical mechanisms of water transportation in the subduction zone from the shallower lithosphere to the uppermost lower mantle by hydrogen transfer between hydrous phases and melts (modified from Pamato et al., 2014). Credit: Ehime University

Researchers at Ehime University have recently measured the propagation speed of ultrasonic waves in an aluminum-rich hydrous mineral called Al-phase D at pressure conditions relevant to the Earth’s deep mantle. Their results suggest that seismic shear anomalies observed locally beneath subduction zones may reveal the presence of hydrous minerals in the uppermost lower mantle, which would have important implications for the Earth’s interior because hydrogen affects considerably the physical and chemical properties of mantle minerals.


Since the discovery of a water-bearing ringwoodite specimen trapped in a superdeep diamond from Brazil by Pearson et al. in 2014 (published in Nature), there is a regained interest for finding and characterizing the potential carrier and host minerals of water in the deep Earth’s interior. Among the candidate minerals, Dense Hydrous Magnesium Silicates (DHMSs) are considered as primary water carriers from the shallow lithosphere to the deep mantle transition zone (MTZ; 410–660 km in depth), but because of their relative instability against pressure (P) and temperature (T), DHMSs were generally associated with the presence of water up to the middle-part of the MTZ.

An experimental study also published in 2014 in the journal Nature Geoscience however showed that when aluminum incorporates DHMSs, their stability against P and T is drastically improved, allowing those minerals to transport and host water up to depths of 1200 km in the lower mantle (Pamato et al., 2014). Their experiments indeed showed that the aluminum-bearing DHMS mineral called Al-phase D is likely to form at the uppermost lower mantle P and T conditions, from the recrystallization of hydrous melt at the boundary of the mantle and the subducted slab. Although this reaction was justified by laboratory experiments, there were no direct measurement of the sound velocities of Al-phase D and therefore it was difficult to associate the presence of Al-rich hydrated rocks to the seismic observations at the bottom of the MTZ and in the uppermost lower mantle.

The researchers at Ehime successfully measured the longitudinal (VP) and shear (VS) velocities, as well as the density of Al-phase D, up to 22 GPa and 1300 K by mean of synchrotron X-ray techniques combined with ultrasonic measurements in situ at high P and and T, in the multi-anvil apparatus located at the beamline BL04B1 in SPring-8 (Hyogo, Japan). The results of their experiments provided a clear understanding of the sound velocities of Al-phase D under a wide P and T range, allowing for modeling the seismic velocities of hydrous rocks in the inner and outer parts of the subducted slab (Image 1). From these models they showed that the presence of an

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Australian Telescope Maps Deep Space at Record Speed | Top News

MELBOURNE (Reuters) – A powerful new telescope in outback Australia has mapped vast areas of the universe in record-breaking time, revealing a million new galaxies and opening the way to new discoveries, the country’s national science agency said on Tuesday.

The radio telescope, dubbed the Australian Square Kilometre Array Pathfinder (ASKAP), was able to map about three million galaxies in just 300 hours. Comparable surveys of the sky have taken as long as 10 years.

“It’s really a game changer,” said astronomer David McConnell, who led the Commonwealth Scientific and Industrial Research Organisation (CSIRO) study of the southern sky at the Murchison Radioastronomy Observatory in Western Australia.

What makes this telescope unique is its wide field of view, using receivers designed by CSIRO, which allow it to take panoramic pictures of the sky in sharper detail than before.

The telescope only needed to combine 903 images to map the sky, compared with other all-sky radio surveys that require tens of thousands of images.

“It is more sensitive than previous surveys that have covered the whole sky like this, so we do see more objects than have been seen in the past,” McConnell told Reuters.

Having a telescope that can survey the sky in a few weeks or months means the process can be repeated again and again in a relatively short space of time, allowing astronomers to systematically spot and track changes.

“Even with this first pass we’ve got right now, compared with previous images, we’ve already found some unusual objects,” McConnell said, including some unusual stars that undergo violent outbursts.

He said data gathered in this survey would allow astronomers to find out more about star formation and how galaxies and black holes evolve through statistical analyses.

The initial results were published on Tuesday in the Publications of the Astronomical Society of Australia.

(Reporting by Sonali Paul; Editing by Lincoln Feast.)

Copyright 2020 Thomson Reuters.

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College football top 25 scores, overreactions, Week 13: Deep Heisman field providing some long-awaited drama

Even as November turns into December, and with college football’s regular season winding down, I’ll shout this from the rooftops: the College Football Playoff chatter takes up too much oxygen. It’s suffocating. This is the case in normal years when teams have an even number of games and heavyweight nonconference matchups have some gravity. But here we are in 2020 where Notre Dame might play 12 games and Ohio State may play five. How does the playoff committee weigh that against other teams in the running?Man, I don’t know. We’re lucky to be playing football at all, and at the rate games are getting postponed/canceled, that luck is going to be at a premium moving forward. 

One of the annual storylines that has taken a backseat in the playoff era is the Heisman race. Some of that is because of what I just mentioned, but some of it is that there have been clear frontrunners in most years. Did anyone think Joe Burrow wasn’t going to win last year? How about Lamar Jackson in 2016? Not every race has been a virtual lock, but there have been obvious choices. 

That’s not the case in 2020.

Just how deep is this race? There are multiple teams with more than one candidate. For example, you could make a case at Alabama for quarterback Mac Jones. He’s up to 2,700 yards passing and 23 touchdowns. Those numbers are among the best in the country. But what about receiver Devonta Smith, who has an argument as not only the best player on their elite offense, but the best receiver in Alabama history (he’s already No. 1 in receiving TDs and will likely be No. 1 in yards). 

Florida is similar. Quarterback Kyle Trask is putting up the type of numbers that win hardware … but is he even the best player on his own team? Tight end Kyle Pitts doesn’t control the game like Trask does, but find me a bigger mismatch in college football right now. He has 11 receiving touchdowns in 24 quarters of football. 

Those two have an embarrassment of riches. So only now, several paragraphs down, am I even mentioning Trevor Lawrence, whose biggest shortcoming has been missing a couple of games due to COVID-19. And while a rough performance against Indiana and coronavirus-related cancellations have hindered his case some, Ohio State quarterback Justin Fields is still at least in the conversation. So, too, is BYU quarterback Zach Wilson with his 34 total touchdowns. 

There are more names, but you get the point. The limited number of votes means you won’t get a ton of players for the finalist ceremony. I’ve long believed the Heisman should open up voting and allow more players to be included; it’s a good chance to tell their stories and highlight their achievements. It won’t happen, but this would be a perfect year for that since the field is so stacked. 

Here’s what else we learned from this weekend’s college football action … 

In

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Scientists call for decade of concerted effort to enhance understanding of the deep seas

Scientists call for decade of concerted effort to enhance understanding of the deep seas
A close-up image of a bamboo coral called Acanella arbuscula taken from ~1000m deep in the North East Atlantic Credit: NERC funded Deep Links Project (University of Plymouth, Oxford University, JNCC, BGS)

The deep seas—vast expanses of water and seabed hidden more than 200 meters below the ocean surface to depths up to 11,000 meters—are recognized globally as an important frontier of science and discovery.


But despite the fact they account for around 60% of Earth’s surface area, large areas remain completely unexplored, yet the habitats they support impact on the health of the entire planet.

Now an international team of scientists, spanning 45 institutions in 17 countries, has called for a dedicated decade-long program of research to greatly advance discovery in these remote regions.

The program—which scientists have named Challenger 150—will coincide with the United Nations Decade of Ocean Science for Sustainable Development, which runs from 2021-2030.

Challenger 150 will generate new geological, physical, biogeochemical, and biological data through a global cooperative of science and innovation, including the application of new technology. These data will be used to understand how changes in the deep sea impact the wider ocean and life on the planet.

Among its key areas of focus are to build greater capacity and diversity in the scientific community, acknowledging the fact that existing deep-sea research is conducted primarily by developed nations with access to resources and infrastructure.

The program will use this new knowledge of the deep to support regional, national, and international decision-making on deep-sea issues such as mining, hydrocarbon extraction, fishing, climate mitigation, laying of fiber optic cables and conservation.

The international team presented the rationale behind the call for action in a comment article in Nature Ecology and Evolution, simultaneously publishing a detailed blueprint of how the actions can be best achieved in Frontiers in Marine Science.

Led by members of the Deep-Ocean Stewardship Initiative (DOSI) and the Scientific Committee on Oceanic Research (SCOR), the authorship reflects both the gender and geographical diversity such a program demands, with authors from the six inhabited continents of the world.

They note that the UN Decade provides an unrivaled opportunity to unite the international science community to deliver a giant leap in our knowledge of the deep seas.

Scientists call for decade of concerted effort to enhance understanding of the deep seas
An outcrop of rock makes a perfect home for many different cold water coral species Credit: NERC funded Deep Links Project (University of Plymouth, Oxford University, JNCC, BGS)

Kerry Howell, Professor of Deep-Sea Ecology at the University of Plymouth (UK) and lead author of the research publications, said: “The deep seas and seabed are increasingly being used by society, and they are seen as a potential future asset for the resources they possess. But managing these resources sustainably requires that we first understand deep-sea ecosystems and their role in our planet, its people and its atmosphere. Our vision is for a 10 year program of science and discovery that is global in scale and targeted towards proving the science to inform decisions around deep-ocean use. We

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How Archaeologists Are Using Deep Learning to Dig Deeper

Finding the tomb of an ancient king full of golden artifacts, weapons and elaborate clothing seems like any archaeologist’s fantasy. But searching for them, Gino Caspari can tell you, is incredibly tedious.

Dr. Caspari, a research archaeologist with the Swiss National Science Foundation, studies the ancient Scythians, a nomadic culture whose horse-riding warriors terrorized the plains of Asia 3,000 years ago. The tombs of Scythian royalty contained much of the fabulous wealth they had looted from their neighbors. From the moment the bodies were interred, these tombs were popular targets for robbers; Dr. Caspari estimates that more than 90 percent of them have been destroyed.

He suspects that thousands of tombs are spread across the Eurasian steppes, which extend for millions of square miles. He had spent hours mapping burials using Google Earth images of territory in what is now Russia, Mongolia and Western China’s Xinjiang province. “It’s essentially a stupid task,” Dr. Caspari said. “And that’s not what a well-educated scholar should be doing.”

As it turned out, a neighbor of Dr. Caspari’s in the International House, in the Morningside Heights neighborhood of Manhattan, had a solution. The neighbor, Pablo Crespo, at the time a graduate student in economics at City University of New York who was working with artificial intelligence to estimate volatility in commodity prices, told Dr. Caspari that what he needed was a convolutional neural network to search his satellite images for him. The two bonded over a shared academic philosophy, of making their work openly available for the benefit of the greater scholarly community, and a love of heavy metal music. Over beers in the International House bar, they began a collaboration that put them at the forefront of a new type of archaeological analysis.

A convolutional neural network, or C.N.N., is a type of artificial intelligence that is designed to analyze information that can be processed as a grid; it is especially well suited to analyzing photographs and other images. The network sees an image as a grid of pixels. The C.N.N. that Dr. Crespo designed starts by giving each pixel a rating based on how red it is, then another for green and for blue. After rating each pixel according to a variety of additional parameters, the network begins to analyze small groups of pixels, then successively larger ones, looking for matches or near-matches to the data it has been trained to spot.

Working in their spare time, the two researchers ran 1,212 satellite images through the network for months, asking it to look for circular stone tombs and to overlook other circular, tomblike things such as piles of construction debris and irrigation ponds.

At first they worked with images that spanned roughly 2,000 square miles. They used three-quarters of the imagery to train the network to understand what a Scythian tomb looks like, correcting the system when it missed a known tomb or highlighted a nonexistent one. They used the rest of the imagery to test the system. The network correctly identified

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Deep Space Might Not Be Completely Dark, New Study Suggests

When we look out at the darkest night skies available on Earth, even the emptiest abyss we can find isn’t completely dark. We can look between the individual stars in the Milky Way, seeing out into the Universe beyond. We can look at the space between the myriad of galaxies populating the Universe, finding many regions without identifiable light sources of any type. But even when we do, the light from our own backyard still gets in our way.

From the Sun, the Earth, the Moon, and the tiny, light-reflecting dust grains found within our Solar System, even the greatest space telescopes of all must contend with this extraneous light from all directions: zodiacal light. From the individual atoms, ions, and molecules present within the Milky Way, a faint galactic glow always appears, as well. But if there were a way to subtract all these excess light sources away, would space appear completely dark, or would there be some light left over: a cosmic optical background? In a fascinating new study, a team from NASA’s New Horizons mission claims to have done this for the first time, claiming that deep space might not be entirely dark, after all. Here’s what they found.

When you think of the abyss of deep space, you probably think of the deepest images ever taken: images like the Hubble eXtreme Deep Field, which have revealed some of the faintest, farthest galaxies ever seen by humanity. These images were constructed brilliantly, by:

  • locating a region of space with no known bright stars or galaxies,
  • away from the plane of the zodiacal light in the Solar System,
  • away from the plane of the Milky Way galaxy,
  • that would be consistently visible by the telescope over a long period of time,
  • and by gathering many long-exposure images across a variety of wavelength ranges.

The Hubble Space Telescope’s first attempt to do this created the original Hubble Deep Field, while upgraded cameras, wider wavelength ranges, superior instrumentation and data processing, and longer observing times wound up creating even deeper images.

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