Physicists Have Figured Out Where The Sun’s Plasma Jets Come From


After over a century of observations and several theories, scientists may have finally nailed the origin of the high-speed plasma blasting through the Sun’s atmosphere several times a day. Using a state-of-the-art computer simulation, researchers have developed a detailed model of these plasma jets, called spicules.

The new findings answer some of the bigger questions in solar physics, including how these plasma jets form and why the Sun’s outer atmosphere is far hotter than the surface.

“This is the first model that has been able to reproduce all the features observed in spicules,” Juan Martinez-Sykora, lead author and astrophysicist at the Bay Area Environmental Research Institute in California, told ScienceAlert.

Every five minutes, spicules shoot red hot streams of charged particles into the corona, the outer layer of the solar atmosphere, at around 150 kilometres (93 miles) per second (paper). Lasting up to 15 minutes it is estimated that up to 300,000 spicules are active at any one time.

The bizarre thing about the corona is that it’s totally counterintuitive when it comes to temperature.

Even though it’s further away, it’s millions of degrees hotter than the Sun’s surface, thanks to the constant supply of hot plasma delivered by the spicules. This jump in temperature is kind of like standing some distance away from a bonfire and feeling hotter than the fire itself.

While scientists have been aware of spicules for over a century, their origin has remained a puzzle. Over the years, there have been several theories that have attempted to crack the mystery.

One study suggested that spicules are generated by massive sound waves, while a more recent study proposed that their formation is due to the magnetic field forming loops out of the atmosphere.

But these theories only provided fragments of the story which failed to explain the origin of spicules and why they are found all over the sun.

Speaking with ScienceAlert, Lockheed and Martin Solar and Astrophysics Laboratory principal physicist Bart de Pontieu said observing the spicules from the ground has its limitations.

“It’s been very hard to get a clear view of what these spicules do, as Earth’s atmosphere creates a murky picture,” said de Pontieu, who was also a co-author on the paper. “But thanks to space telescopes, we can now see what they really look like in greater detail.”

And now, Martinez-Sykoro and his team have developed a computer model that can generate simulations of these powerful plasma jets in action, allowing the researchers to track different temperatures and physical features.

The numerical model revealed that the formation of spicules happens in three distinct stages.

The process begins on the surface of the Sun where churning plasma interacts with the magnetic fields, which get twisted up and knotted in the process. This distortion creates strong magnetic tension trapped close to the surface.

Next, neutral and charged particles mix above the surface in a process called ambipolar diffusion, which creates an escape route for the building magnetic tension. Then, like a slingshot, the magnetic tension is violently released into the atmosphere and out into space at staggering speed.

“These jets of plasma are ejected so fast that they could traverse the length of California in just a couple of minutes,” De Pontieu told ScienceAlert. “They can reach heights of 10,000 kilometres, roughly the diameter of Earth, in just five to ten minutes.”

To see how the simulations stacked up against the real thing, the team analysed data from NASA’s Interface Region Imaging Spectrograph and the Swedish Solar Telescope. They found that the simulations recreated the properties of actual spicules, including the size, speed and shape.

In addition to solving the long-held mystery of how spicules form, the new findings demonstrate how the plasma jets blast millions of degrees of heat into the scorching corona.

“It’s exciting because it explains why the solar atmosphere is millions of degrees hotter than the surface,” De Pontieu told ScienceAlert.

Now that scientists know how spicules form, they can take a closer look at how they interact with the outer reaches of the solar atmosphere.

The study has been published in Science.

Here’s How to Backup Life on Earth Ahead of Any Doomsday Event


There are ten asteroids that the space organisation NASA said last month have been classified as “potentially hazardous” based on their size and their orbits in our Solar system.

NASA has now identified 693 near-Earth objects thanks to the Wide-field Infrared Survey Explorer spacecraft that’s been looking for potential threats to Earth since 2013.

 

The organisation doesn’t specify what kind of hazard these ten asteroids pose.

But Earth has been hit by objects in the past, with devastating effects. Scientists largely agree that it was an asteroid or comet impact that started the chain of events that wiped out the dinosaurs around 60 million years ago.

Every year several previously unseen asteroids whizz past Earth, sometimes with only with a few days’ warning. This year two of these asteroids came very close to Earth, with one in May sailing past only 15,000km away.

On cosmic scales, that was a very close shave.

But impacts from objects in space are just one of several ways that humanity and most of life on Earth could suddenly disappear.

We are already observing that extinctions are happening now at an unprecedented rate. In 2014 it was estimated that the extinction rate is now 1,000 times greater than before humans were on the Earth.

The estimated number of extinctions ranges from 200 to 2,000 species per year.

From all of this very worrying data, it would not be a stretch to say that we are currently within a doomsday scenario. Of course, the “day” is longer than 24 hours but may be instead in the order of a century or two.

So what can we do about this potential prospect of impending doom? We can try to avoid some of the likely scenarios.

We should act to tackle climate change and we can develop new asteroid-tracking systems and put in place a means to deflect an asteroid on a collision course with Earth.

But the threats we face are so unpredictable that we need to have a backup plan. We need to plan for the time after our doomsday and think about how a post-apocalyptic Earth may recover and humanity will flourish again.

A backup plan

Some efforts to backup life on our planet have already started. Since the 1970s scientists around the world began to store seeds of potentially endangered plants. There are now dozens of seed banks or vaults scattered around the world.

The most famous is the Svalbard Global Seed Vault, located on a remote Norwegian island about 1,300 kilometres from the North Pole. The location was deliberately chosen to afford the project safe and secure long-term storage in cold and dry rock vaults.

But there were reports earlier this year that the vault had suffered issues with water from the surrounding melting permafrost (caused by global warming) gaining entry to parts of the structure.

Less common are vaults for storing biological material from animals. There are a handful of so-called frozen zoos around the world.

They store embryos, eggs, sperm and more recently DNA of endangered animals. So far, sperm, eggs and embryos that have been frozen for roughly 20 years have been shown to be viable.

All of the storage methods that involve freezing have the same problem that the material is at risk of thawing out if the freezing methods fail. Storing frozen biological material for centuries or even millennia on Earth is not realistic.

Humans can now sequence a whole genome of a living organism and the cost has reduced to the point where it costs less than US$1,000 to sequence the human genome. This process effectively turns the information from any organism’s cells into data.

If future scientists can create living DNA from the genome data and can then create living organisms from that DNA, then having the data alone may be sufficient to backup the Earth’s living organisms.

Where to store the backups?

But where should humanity store the backups? As French president Emmanuel Macron said recently, “there is no plan B because there is no planet B”, echoing 2014 commentsfrom Ban Ki-moon when he was secretary general of the United Nations.

Backing up on Earth seems a high-risk strategy, equivalent to having a computer backup on an external hard drive that sits right next to your computer.

So given that the motivation for backing up Earth’s organisms is the likelihood of Earth itself suffering a catastrophe, it follows that our planet is not the best location for the backups.

The partial flooding of the Svalbard Global Seed Vault illustrates that perfectly.

Perhaps the obvious place to locate the backups is in space.

Seeds have already been taken to space for short periods (six months) to test their viability back on Earth. These experiments so far have been motivated by the desire to eventually grow plants in space itself, on space stations, or on Mars.

Space is a harsh environment for biological material, where cells are exposed to potentially very high doses of radiation that will damage DNA.

Storage of seeds in low Earth orbit is desirable as Earth’s magnetic field provides some protection from space radiation. Storage outside of this zone and in deep space would require other methods of radiation protection.

The other question is how you would get seeds and other biological material safely back to Earth after a global disaster. Now we get to the robotics that can help, as autonomous re-entry of biological material from orbit is totally feasible.

The tricky part is for our orbiting bio-backup to know when its cargo is required and where to send it to. Perhaps we need a global limited robot crew – such as David in the recent Alien films – that would wake up the orbiter when it is needed.

Alternatively, it could be staffed by a rotating crew of wardens similar to the International Space Station. These people could carry out other important scientific work too.

Other locations in space for storage of biological material or data include the Moon, and the moons of our solar system’s gas planets asteroids or deep space itself on free flying spacecraft.

Such projects have been proposed and groups around the world have begun planning such ventures.

The ConversationSo it seems that some people have already accepted the fate of humanity version 1.0 and that it will end sometime in the relative near term. The movement to create our backup ready for humanity version 2.0 has already begun.

Half a Million People Have Bombarded ‘Space Nation’ Asgardia With Citizenship Applications


Stop the planet, we want to get off.

Custodians of the hypothetical ‘space nation’ Asgardia will be launching their first ever satellite in the coming months, and they’ve finally revealed their initial plans for the hundreds of thousands of people who have already applied for citizenship.

While more than 500,000 people have already registered their interest, the team behind the off-planet nation state announced that applications are still open, and more than 1 million ‘citizens’ will be given the opportunity to store data on their satellite, free of charge and free from Earthly laws and regulations.

“These are historic days,” said Russian scientist and ‘Head of Nation’, Igor Ashurbeyli, at the press conference this week in Hong Kong.

“[Y]our names and data will forever stay in the memory of the new space humanity, as they will be reinstalled on every following Asgardia satellite, orbital satellite constellations, on the Moon, and anywhere in the Universe – wherever Asgardia will be.”

For those who missed the hype, late last year an international group of scientists announced plans to establish Asgardia – a permanent space station that will house space tourists, run asteroid mining missions, and provide defence for Earth against meteorites, space debris, and other serious threats.

When they opened up applications in October, they said the first 100,000 applicants would be granted citizenship of Asgardia alongside their nationality on Earth.

But since then, more than 500,000 people have registered their interest, and in response to the influx, the Asgardian team has expanded their plans to let more than a million people take part in the initial stages of their plans.

asgardia bodyCredit: Asgardia

“After they have accepted the Constitution, Asgardians are encouraged to send their files to space,” the researchers explain.

“The first 100,000 people who became Asgardian citizens can send up to 500KB each to Asgardia-1. The next 400,000 Asgardians can send up to 200KB. The next million citizens can send up to 100KB each. After that, free storage will be closed.”

(Note that the press release has two dates – 25 June 0001 and 14 June 2017 – because of course they have their own calendar.)

The group plans to launch their satellite by September 2017, piggybacking on a supply mission to the International Space Station (ISS).

The tiny CubeSat satellite – measuring approximately 10 cm on each side, and weighing around 1 kilogram – will carry a 512GB solid state drive pre-loaded with data.

But before that happens, some housekeeping must be sorted out, so on June 18, the Asgardian flag, insignia, and national anthem are set to be finalised.

In six months’ time, the group expects to have the first Parliament of Asgardia established.

Of course, there’s no telling when or if the actual point of all this – that lawless off-planet settlement – will ever actually become a reality, but it’s certainly fun to think about.

Case in point: this amazing set of “Frequently Asked Questions” on the Asgardia website.

Here are a few highlights:

  • I got my Asgardian citizenship. Are my children considered Asgardians?

    As per Asgardia’s Constitution, any child born to at least one Asgardian parent is considered an Asgardian citizen by virtue of birth. A child born before the foundation of Asgardia may become a citizen the request of their parent(s) who are Asgardian citizen(s).

  • Will Asgardia become a member of Olympic and Paralympic Committees and participate in Olympic and Paralympic Games?

    Asgardia plans to apply for membership in the International Olympic Committee.

  • Will there be an Asgardian embassy in my country?

    There will be Asgardian embassies on each continent.

  • Will Asgardia have its own TV channel?

    Yes, Asgardia plans to eventually launch its own TV channel.

God speed, you crazy dreamers. We can’t wait to see what happens next.

What Makes a Star a Star?


Brown dwarfs vs true stars.

How do you separate a true star from the stellar wannabes of the Universe? After a decade of collecting data, astronomer Trent Dupuy thinks he finally has the answer.

With so many objects known to sit in that weird middle ground between giant planets and tiny stars, scientists have struggled to boil it down to a simple answer. What Dupuy boils it down to is mass.

“Mass is the single most important property of stars because it dictates how their lives will proceed,” Dupuy, from the University of Texas at Austin, explained at the American Astronomical Society’s summer meeting earlier this month.

We benefit from that here on Earth, as our Sun is in the stellar goldilocks zone – its mass is just right to sustain nuclear fusion within its core for billions of years. This has provided the conditions for life to develop and evolve on our planet.

But not everything in the galaxy is so nice and stable. More massive stars burn through their nuclear fuel quicker, dye young, and go out with a violent bang in the form of a supernova.

Less massive objects, like brown dwarfs, are like stellar runts, possessing more mass than a planet, yet not enough mass to be a fully fledged star.

Often referred to as failed stars, they’re ubiquitous throughout the Universe, but their exceedingly dim glow makes these objects difficult to study.

First proposed to exist 50 years ago, these enigmatic objects help bridge the gap between stars and planets, but it wasn’t until more recently that astronomers began to study them in great detail.

“When we look up and see the stars shining at night, we are seeing only part of the story,” Dupuy explains.

“Not everything that could be a star ‘makes it,’ and figuring out why this process sometimes fails is just as important as understanding when it succeeds.”

Stars like the Sun shine as a result of nuclear reactions that constantly converts the supply of hydrogen in their cores into helium.

These same reactions determine how bright a star shines – the hotter the core, the more intense the reaction and subsequently the brighter the star’s surface will be. As expected, less massive stars are dimmer due to cooler centres, which produce slower reactions.

Don’t let the name fool you – brown dwarfs aren’t always brown. These stellar wannabes are actually red when they form, then turn to black as they slowly fizzle out over trillions of years.

That’s because despite outweighing even the largest of planets, brown dwarfs have so little mass that their centres aren’t hot enough to sustain nuclear reactions.

In the 1960s, astronomers theorised that there must be a mass limit for fusion.

“Below this limit there’s not to replenish the energy that’s constantly being radiated into space,” Dupuy explained in his AAS session. “Objects with a given mass below this limit would simply cool forever.”

Previous studies of stellar evolution have suggested that the boundary between red dwarfs (the smallest stars) and brown dwarfs was around 75 Jupiter masses (or roughly 7-8 percent of the Sun). But until now, his measurement was never directly confirmed.

Dupuy and Michael Lui of the University of Hawaii spent the past 10 years studying 31 binary pairs of brown dwarfs with the help of the most powerful telescopes on Earth – the Keck Observatory and the Canada-France-Hawaii Telescope, as well as some input from Hubble.

By analysing a decade’s worth of imagery, Dupuy and Liu have created the first large sample study of brown dwarfs masses.

According to Dupuy, an object must weigh the equivalent of 70 Jupiters in order to spark nuclear fusion and become a star, which is slightly less than previously suggested.

The duo also determined there’s a temperature cut-off, with any object cooler than 1,600 Kelvin (approximately 1,315 Celsius and 2,400 degrees Fahrenheit) classified as a brown dwarf.

The study will help astronomers better understand the conditions under which stars form and evolve – or in the case of brown dwarfs, fail.

It could also provide new insight into planetary formation as the success or failure of star formation directly impacts the star systems they could potentially produce.

Source: The Astrophysical Journal Supplement, 

NASA wants to launch a giant magnetic field to make Mars habitable. 


NASA scientists have proposed a bold plan that could give Mars its atmosphere backand make the Red Planet habitable for future generations of human colonists.

By launching a giant magnetic shield into space to protect Mars from solar winds, the space agency says we could restore the Red Planet’s atmosphere, and terraform the Martian environment so that liquid water flows on the surface once again.

 

Mars may seem like a cold, arid wasteland these days, but the Red Planet is thought to have once had a thick atmosphere that could have maintained deep oceans filled with liquid water, and a warmer, potentially habitable climate.

Scientists think Mars lost all of this when its protective magnetic field collapsed billions of years ago, and solar wind – high-energy particles projected from the Sun – has been stripping the Red Planet’s atmosphere away ever since.

Now, new simulations by NASA suggest there could be a way to naturally give Mars its thick atmosphere back – and it doesn’t require nuking the Red Planet into submission, as Elon Musk once proposed.

Instead, the space agency thinks a powerful-enough magnetic shield launched into space could serve as a replacement for Mars’s own lost magnetosphere, giving the planet a chance to naturally restore its own atmosphere.

In new findings presented at the Planetary Science Vision 2050 Workshop last week, NASA’s Planetary Science Division director, Jim Green, said launching an “artificial magnetosphere” into space between Mars and the Sun could hypothetically shield the Red Planet in the extended magnetotail that trails behind the protective field.

“This situation then eliminates many of the solar wind erosion processes that occur with the planet’s ionosphere and upper atmosphere allowing the Martian atmosphere to grow in pressure and temperature over time,” the researchers explain in an accompanying paper.

 While the team acknowledges that the concept might sound “fanciful”, they point to existing miniature magnetosphere research being conducted to protect astronauts and spacecraft from cosmic radiation, and think that the same technology on a larger scale could be used to shield Mars.

“It may be feasible that we can get up to these higher field strengths that are necessary to provide that shielding,” Green said in his presentation.

“We need to be able then to also modify that direction of the magnetic field so that it always pushes the solar wind away.”

In the team’s simulations, if the solar wind were counteracted by the magnetic shield, Mars’s atmospheric losses would stop, and the atmosphere would regain as much as half the atmospheric pressure of Earth in a matter of years.

As the atmosphere becomes thicker, the team estimates Mars’s climate would become around 4 degrees Celsius (7.2 degrees Fahrenheit) warmer, which would be enough to melt carbon dioxide ice over the Red Planet’s northern polar cap.

If this happened, the carbon in the atmosphere would help to trap heat like it does on Earth, triggering a greenhouse effect that could melt Mars’s water ice, giving the Red Planet back its liquid water in the form of flowing rivers and oceans.

If all of this were to occur as the team anticipates – and admittedly, that’s a pretty fantastical if – it’s possible that, within the space of a couple of generations, Mars could regain some of its lost Earth-like habitability.

“This is not terraforming as you may think of it where we actually artificially change the climate, but we let nature do it, and we do that based on the physics we know today,” Green said.

The team acknowledges that the plan is largely hypothetical at this point, but it’s a pretty amazing vision for what might be possible in the years ahead. The researchers intend to keep studying the possibilities to get a more accurate estimate of how long the climate-altering effects would take.

If the concept does prove workable, there’s no telling just how much it would alter the prospects of colonising Mars in the future.

“Much like Earth, an enhanced atmosphere would: allow larger landed mass of equipment to the surface, shield against most cosmic and solar particle radiation, extend the ability for oxygen extraction, and provide ‘open air’ green-houses to exist for plant production, just to name a few,” the researchers explain.

“If this can be achieved in a lifetime, the colonisation of Mars would not be far away.”

Here’s What We’d Need to Transform Wormholes Into Intergalactic Shortcuts. 


Everyone likes a shortcut and a quick trip somewhere cool, which means that everyone loves a wormhole – at least in theory. In actuality, these space-time tunnels are probably not the alleged intergalactic shortcuts we’re looking for – and this isn’t a mind trick from Obi-Wan, either.

But first, let’s talk about what wormholes are and how they could theoretically allow for faster-than-light travel; it’s always better to build up all of our hopes before dashing them to pieces, I find.

 When physicists started tinkering with general relativity, they predicted that black holes might exist. The same physics that predicts black holes also predicts white holes, which are just what they sound like: the opposite of black holes.

The event horizon of a black hole is a corner of space that is impossible to escape once you’ve entered it. On the other hand, the event horizon of a white hole is impossible to enter – but you can escape if you’re already there.

The wormhole comes in when we learn that all black holes are naturally connected to white holes; these identically opposite twins are joined at the singularities.

Or so the math says. While we’ve seen black holes a-plenty, there’s no evidence at all for white holes – nor any evidence for any process that could form them, or any means for them to stay in existence if they formed, or even any way they could survive their ‘symbiotic’ connections to black holes.

There is just no way they could ever form, or be stable enough to remain once formed. That instability would directly affect any wormholes: they would never be able to last, and would instead stretch and break almost immediately.

If you happened to see a wormhole and went for a ride, you’d be on a one way trip into an event horizon of a black hole. That sounds cool, but remember: you’d then be stretched endlessly and pummeled to death by gravity (and even Anthony Perkins thinks that’s crazy).

 However, some still believe that we can make wormholes work for us, as sort of a next level tube system going all over the universe rather than just beneath London.

To make it work, you’d need to enter just outside the event horizon so you could get through the wormhole without getting done in by gravity first.

You’d also need a tunnel strong and stable enough to handle both the gravitational pummeling mentioned above, and the force of people flying through it at extreme speeds.

blackhole wormhole

What would make that possible? A tunnel made of negative-mass material. Negative-mass materials have not been found in the universe anywhere, although physicists in Washington recently created a fluid with negative-mass.

So will they someday create negative-mass material that you could, say, build a tunnel with? Maybe.

 Will we ever find workable wormholes?

Still, should this really be a priority? There are plenty of reasons why traveling this quickly would mean a lot to humanity: we could explore far reaches of the galaxy, potentially finding alien life, more habitable planets, and whatever else it has to offer – probably a lot.

However, we don’t need to pin all of our hopes on wormholes just because we wish to traverse the galaxy.

First of all, even breakthroughs in physics such as the creation of negative-mass materials are unlikely to lead to workable wormholes.

These fantastical space travel tunnels would violate numerous laws of physics- many of which are very well-tested. The odds of defeating each and every one of them seem long, indeed.

Furthermore, there are a number of other projects in the works that could help us travel faster in space. NASA and others have been studying the EM Drive, a radio frequency resonant cavity thruster that uses microwaves inside a truncated cone to create a thrust at the narrow end of the cone.

If it works, it would mean the ability to create thrust without a propellant – a huge advancement for long-distance space travel. This tech is a long way from being viable, however.

Ion propulsion is already being used once rockets are already in space. NASA’s Dawn mission uses ion propulsion, as do several other missions from Japan and the ESA.

How long it will be before the technology could be used to help humans travel extremely long distances, however, remains to be seen.

In short, it seems unlikely that a solution that would require breaking every law in the physics book will be the one that gets us there. As fun as wormholes feel from the outside, they’re probably not worth too much of our focus.

Are gravitational waves kicking this black hole out of its galaxy?


Astronomers have just spied a black hole with a mass 1 billion times the sun’s hurtling toward our galaxy. But scientists aren’t worried about it making contact: It’s some 8 billion light-years away from Earth and traveling at less than 1% the speed of light. Instead, they’re wondering how it got the boot from its parent galaxy, 3C186 (fuzzy mass in the Hubble telescope image, above). Most black holes lie quietly—if voraciously—at the center of their galaxies, slurping up the occasional passing star.

But every once in a while, two galaxies merge, and the black holes in their centers begin to swirl around each other in a pas des deux that eventually leads to a devastating merger. The wandering black hole (bright spot above), may be the result of one such merger. Based on the wavelengths of spectral lines emitted by the luminous gas surrounding the black hole, the object is traveling at a speed of about 7.5 million kilometers per hour—a rate that would carry it from Earth to the moon in about 3 minutes. If the most likely scenario is true, then a massive kick from the merger of two black holes some 1.2 billion years ago would have created a ripple of gravitational waves, the researchers suggest in a forthcoming issue of Astronomy & Astrophysics. And if the precollision black holes didn’t have the same mass and rotation rate as each other, the waves would have been stronger in some directions than others, giving the resulting object a jolt equivalent to the energy of 100 million supernovae exploding simultaneously, the researchers estimate. Other runaway black holes have been proposed, but none of them has yet been confirmed.

Yuri Milner’s 10-year alien-hunting project just posted its first data


  • Yuri Milner began a $100 million effort to listen for aliens in 2015.
  • It’s called Breakthrough Listen, and it’s a network of radio telescopes that target nearby stars and galaxies for 10 years.
  • The first batch of data found 11 significant “hits” out of millions.
  • None of them are evidence of aliens, but the project is just getting started.

alien spacecraft extraterrestrial propulsion lasers illustration m weiss cfa

In July of 2015, Breakthrough Initiatives — a non-profit dedicated to the search for extra-terrestrial intelligence, founded by Yuri Milner — announced the creation of Breakthrough Listen.

A 10-year initiative costing $100 million, this program was aimed at using the latest in instrumentation and software to conduct the largest survey to date for extraterrestrial communications, encompassing the 1,000,000 closest stars and 100 closest galaxies.

On Thursday, April. 20th, at the Breakthrough Discuss conference, the organization shared their analysis of the first year of Listen data. Gathered by the Green Bank Radio Telescope, this data included an analysis of 692 stars, as well as 11 events that have been ranked for having the highest significance.

The results have been published on the project’s website, and will soon be published in the Astrophysical Journal.

Since 2016, Breakthrough Listen has been gathering data with the Green Bank Radio Telescopein West Virginia, the Lick Observatory’s Automated Planet Finder on Mt. Hamilton in California, and the Parkes Radio Telescope in Australia. This data is analyzed by the Listenscience team at the Berkeley SETI Research Center (BSRC), who rely on a specially-designed data pipeline to scan through billions of radio channels for any sign of unique signals.

green bank radio telescope nrao aui nsfThe Green Bank Telescope (GBT), a radio telescope located at the Green Bank Observatory in West Virginia.NRAO/AUI/NSF

While the results were not exactly definitive, this is just the first step in a program that will span a decade.

As Dr. Andrew Siemion, the Director of the BSRC, explained in a BI press release:

“With the submission of this paper, the first scientific results from Breakthrough Listen are now available for the world to review. Although the search has not yet detected a convincing signal from extraterrestrial intelligence, these are early days. The work that has been completed so far provides a launch pad for deeper and more comprehensive analysis to come.”

The Green Bank Telescope searched for these signals using its “L-band” receiver, which gathers data in frequencies ranging from 1.1 to 1.9 GHz. At these frequencies, artificial signals can be distinguished from natural sources, which includes pulsars, quasars, radio galaxies and even the Cosmic Microwave Background (CMB).

Within these parameters, the BSRC team examined 692 stars from its primary target list.

For each star, they conducting three five-minutes observation periods, while also conducting five-minute observations on a set of secondary targets. Combined with a Doppler drift search — a perceived difference in frequency caused by the motion of the source or receiver (i.e. the star and/or Earth) — the Listen science team identified channels where radio emission were seen for each target (aka. “hits”).

CSIROs Parkes radio telescope dishThe Parkes radio telescope, one of the telescopes comprising CSIRO’s Australia Telescope National Facility.CSIRO

This led to a combined 400 hours and 8 petabytes worth of observational data. All together, the team found millions of hits from the sample data as a whole, and 11 events that rose above the threshold for significance.

These events (which are listed here) took place around 11 distant stars and ranged from to 25.4 to 3376.9 SNR (Signal-to-Noise Ratio). However, the vast majority of the overall hits were determined to be the result of radio frequency interference from local sources.

What’s more, further analysis of the 11 events indicated that it was unlikely that any of the signals were artificial in nature. While these stars all exhibited their own unique radio “fingerprints”, this is not necessarily an indication that they are being broadcast by intelligent species.

But of course, finding localized and unusual radio signals is an excellent way to select targets for follow-up examination. And if there is evidence to be found out there of intelligent species using radio signals to communicate, Breakthrough Listen is likely to be the one that finds them.

Of all the SETI programs mounted to date, Listen is by far the most sophisticated.

Not only do its radio surveys cover 10 times more sky than previous programs, but its instruments are 50 times more sensitive than telescopes that are currently engaged in the search for extra-terrestrial life. They also cover 5 times more of the radio spectrum, and at speeds that are 100 times as fast.

Between now and when it concludes in the coming decade, the BSRC team plans to release updated Listen data once every six months.

lick observatory automated planet finder copyright laurie hatchAerial view of the Automated Planet Finder at the Lick Observatory.UC Berkeley/Lick Observatory/Laurie Hatch

In the meantime, they are actively engaging with signal processing and machine learning experts to develop more sophisticated algorithms to analyze the data they collect. And while they continue to listen for extra-solar sources of life, Breakthrough Starshot continues to develop the first concept for a laser-driven lightsail, which they hope will make the first interstellar voyage in the coming years.

And of course, we here in the Solar System are looking forward to missions in the coming decade that will search for life right here, in our own backyard. These include missions to Europa, Enceladus, Titan, and other “ocean worlds” where life is believed to exist in some exotic form!

Source:http://www.businessinsider.com

 

Cassini, Voyager missions suggest new picture of Sun’s interaction with galaxy


 

NASA's Cassini, Voyager missions suggest new picture of Sun's interaction with galaxy
New data from NASA’s Cassini, Voyager and Interstellar Boundary Explorer missions show that the heliosphere — the bubble of the sun’s magnetic influence that surrounds the inner solar system — may be much more compact and rounded than previously thought. The image on the left shows a compact model of the heliosphere, supported by this latest data, while the image on the right shows an alternate model with an extended tail. The main difference is the new model’s lack of a trailing, comet-like tail on one side of the heliosphere. This tail is shown in the old model in light blue. 

New data from NASA’s Cassini mission, combined with measurements from the two Voyager spacecraft and NASA’s Interstellar Boundary Explorer, or IBEX, suggests that our sun and planets are surrounded by a giant, rounded system of magnetic field from the sun—calling into question the alternate view of the solar magnetic fields trailing behind the sun in the shape of a long comet tail.

The sun releases a constant outflow of magnetic solar material—called the —that fills the inner solar system, reaching far past the orbit of Neptune. This solar wind creates a bubble, some 23 billion miles across, called the . Our entire solar system, including the heliosphere, moves through interstellar space. The prevalent picture of the heliosphere was one of comet-shaped structure, with a rounded head and an extended . But  covering an entire 11-year solar activity cycle show that may not be the case: the heliosphere may be rounded on both ends, making its shape almost spherical. A paper on these results was published in Nature Astronomy on April 24, 2017.

“Instead of a prolonged, comet-like tail, this rough bubble-shape of the heliosphere is due to the strong —much stronger than what was anticipated in the past—combined with the fact that the ratio between particle pressure and magnetic pressure inside the heliosheath is high,” said Kostas Dialynas, a space scientist at the Academy of Athens in Greece and lead author on the study.

An instrument on Cassini, which has been exploring the Saturn system over a decade, has given scientists crucial new clues about the shape of the heliosphere’s trailing end, often called the heliotail. When charged  from the inner solar system reach the boundary of the heliosphere, they sometimes undergo a series of charge exchanges with neutral gas atoms from the interstellar medium, dropping and regaining electrons as they travel through this vast boundary region. Some of these particles are pinged back in toward the inner solar system as fast-moving , which can be measured by Cassini.

NASA's Cassini, Voyager missions suggest new picture of Sun's interaction with galaxy
Many other stars show tails that trail behind them like a comet’s tail, supporting the idea that our solar system has one too. However, new evidence from NASA’s Cassini, Voyager and Interstellar Boundary Explorer missions suggest that the trailing end of our solar system may not be stretched out in a long tail. From top left and going counter clockwise, the stars shown are LLOrionis, BZ Cam and Mira. 

“The Cassini instrument was designed to image the ions that are trapped in the magnetosphere of Saturn,” said Tom Krimigis, an instrument lead on NASA’s Voyager and Cassini missions based at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland, and an author on the study. “We never thought that we would see what we’re seeing and be able to image the boundaries of the heliosphere.”

 Cassini’s new measurements of these neutral atoms revealed something unexpected—the particles coming from the tail of the heliosphere reflect the changes in the solar cycle almost exactly as fast as those coming from the nose of the heliosphere.

“If the heliosphere’s ‘tail’ is stretched out like a comet, we’d expect that the patterns of the solar cycle would show up much later in the measured neutral atoms,” said Krimigis.

NASA's Cassini, Voyager missions suggest new picture of Sun's interaction with galaxy
New data from NASA’s Cassini, Voyager and Interstellar Boundary Explorer missions show that the heliosphere — the bubble of the sun’s magnetic influence that surrounds the inner solar system — may be much more compact and rounded than previously thought. This illustration shows a compact model of the heliosphere, supported by this latest data. The main difference between this and previous models is Credit: Dialynas, et al.the new model’s lack of a trailing, comet-like tail on one side of the heliosphere. 

But because patterns from solar activity show just as quickly in tail particles as those from the nose, that implies the tail is about the same distance from us as the nose. This means that long, comet-like tail that scientists envisioned may not exist at all—instead, the heliosphere may be nearly round and symmetrical.

A rounded heliosphere could come from a combination of factors. Data from Voyager 1 show that the interstellar magnetic field beyond the heliosphere is stronger than scientists previously thought, meaning it could interact with the solar wind at the edges of the heliosphere and compact the heliosphere’s tail.

The structure of the heliosphere plays a big role in how particles from interstellar space—called cosmic rays—reach the inner solar system, where Earth and the other planets are.

“This data that Voyager 1 and 2, Cassini and IBEX provide to the scientific community is a windfall for studying the far reaches of the solar wind,” said Arik Posner, Voyager and IBEX program scientist at NASA Headquarters in Washington, D.C., who was not involved with this study. “As we continue to gather data from the edges of the heliosphere, this data will help us better understand the interstellar boundary that helps shield the Earth environment from harmful cosmic rays.”

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