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Inflatable space stations could orbit the Earth by 2020

Inflatable space stations could orbit the Earth by 2020 | Amazing Science | Scoop.it

The latest SpaceX launch ferried not just supplies for the ISS, but also aninflatable module designed to add a small living room on the space station. That module was made by Bigelow Aerospace, which has just announcedthat it teamed up with United Launch Alliance to send its much, much bigger inflatable stations called B330 to Low Earth Orbit. One B330 can add a 330-cubic-meter (or 12,000-cubic-foot) living space to the ISS -- that's 30 percent of its total size, whereas the model that piggybacked on Falcon 9 can only expand the station by five percent.

 

In order to fit inside an Atlas V rocket, a B330 will be folded when it takes off from Earth. Even then, the Atlas V is the only rocket with a big enough payload compartment to accommodate one. That likely played a huge part in Bigelow's decision to strike a deal with ULA.

 

Besides expanding the ISS, several B330s can be linked together to form an independent space station, as well. The companies can then rent them out to private corporations and institutions that want to perform non-government scientific research in microgravity. They also think that some companies like Disney could turn them into exciting and (quite literally) out of this world tourist destinations.

 

If NASA agrees to test the B330 on the ISS like it agreed to test out its smaller predecessor for the next two years, then it will be financing the first module's launch. Either way, the duo aims to send the first of the two inflatable habitats they're planning to space sometime in 2020.

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1917 astronomical plate has first-ever evidence of exoplanetary system

1917 astronomical plate has first-ever evidence of exoplanetary system | Amazing Science | Scoop.it

You can never predict what treasure might be hiding in your own basement. We didn’t know it a year ago, but it turns out that a 1917 image on an astronomical glass plate from our Carnegie Observatories’ collection shows the first-ever evidence of a planetary system beyond our own Sun. This unexpected find was recognized in the process of researching an article about planetary systems surrounding white dwarf stars in New Astronomy Reviews.

 

Here’s what happened: about a year ago, the review’s author, Jay Farihi of University College London, contacted our Observatories’ Director, John Mulchaey. He was looking for a plate in the Carnegie archive that contained a spectrum of van Maanen’s star, a white dwarf discovered by Dutch-American astronomer Adriaan van Maanen in the very year our own plate was made.

 

Stellar spectra are recordings of the light emitted by distant stars. Spectra spread out all of the component colors of light, like a rainbow from a prism, and they can teach astronomers about a star’s chemical composition. They can also tell them how the light emitted by a star is affected by the chemistry of the things it passes through before reaching us on Earth.

 

Stellar spectra images allowed 19th century astronomers to develop a system for classifying stars that is still used today. Modern astronomers use digital tools to image stars, but for decades, they would use glass photographic plates both to take images of the sky, and to record stellar spectra.

 

As requested, the Observatories located the 1917 plate, made by former Observatories Director Walter Adams at Mount Wilson Observatory, which was then part of Carnegie. Other than a notation on the plate’s sleeve indicating that the star looked a bit warmer than our own Sun, everything seemed very ordinary.

However, when Farihi examined the spectrum, he found something quite extraordinary.

 

The clue was in what’s called an “absorption line” on the spectrum. Absorption lines indicate “missing pieces,” areas where the light coming from a star passed through something and had a particular color of light absorbed by that substance. These lines indicate the chemical makeup of the interfering object.

 

Carnegie’s 1917 spectrum of van Maanen’s star revealed the presence of heavier elements, such as calcium, magnesium, and iron, which should have long since disappeared into the star's interior due to their weight.

 

Only within the last 12 years has it become clear to astronomers that van Maanen's star and other white dwarfs with heavy elements in their spectra represent a type of planetary system featuring vast rings of rocky planetary remnants that deposit debris into the stellar atmosphere. These recently discovered systems are called “polluted white dwarfs.” They were a surprise to astronomers, because white dwarfs are stars like our own Sun at the end of their lifetimes, so it was not at all expected that they would have leftover planetary material around them at that stage.

 

“The unexpected realization that this 1917 plate from our archive contains the earliest recorded evidence of a polluted white dwarf system is just incredible,” Mulchaey said. “And the fact that it was made by such a prominent astronomer in our history as Walter Adams enhances the excitement.”

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Astronomers iscover mysterious alignment of black holes

Astronomers iscover mysterious alignment of black holes | Amazing Science | Scoop.it

Deep radio imaging by researchers in the University of Cape Town and University of the Western Cape, in South Africa, has revealed that supermassive black holes in a region of the distant universe are all spinning out radio jets in the same direction -- most likely a result of primordial mass fluctuations in the early universe. The astronomers publish their results in a new paper in Monthly Notices of the Royal Astronomical Society.

 

The new result is the discovery -- for the first time -- of an alignment of the jets of galaxies over a large volume of space, a finding made possible by a three-year deep radio imaging survey of the radio waves coming from a region called ELAIS-N1 using the Giant Metrewave Radio Telescope (GMRT).

 

The jets are produced by the supermassive black holes at the centres of these galaxies, and the only way for this alignment to exist is if supermassive black holes are all spinning in the same direction, says Prof Andrew Russ Taylor, joint UWC/UCT SKA Chair, Director of the recently-launched Inter-University Institute for Data Intensive Astronomy, and principal author of the MNRAS study.

 

"Since these black holes don't know about each other, or have any way of exchanging information or influencing each other directly over such vast scales, this spin alignment must have occurred during the formation of the galaxies in the early universe," he notes.

 

This implies that there is a coherent spin in the structure of this volume of space that was formed from the primordial mass fluctuations that seeded the creation of the large-scale structure of the universe.

 

With study co-author -- and UCT PhD student currently working at the National Radio Astronomy Observatory, Socorro, New Mexico, USA -- Preshanth Jagannathan, the team discovered the alignment after the initial image had been made. Within the large-scale structure, there were regions where the spin axes of galaxies lined up.

 

The finding wasn't planned for: the initial investigation was to explore the faintest radio sources in the universe, using the best available telescopes -- a first view into the kind of universe that will be revealed by the South African MeerKAT radio telescope and the Square Kilometre Array (SKA), the world's most powerful radio telescope and one of the biggest scientific instruments ever devised.

 

Earlier observational studies had previously detected deviations from uniformity (so-called isotropy) in the orientations of galaxies. But these sensitive radio images offer a first opportunity to use jets to reveal alignments of galaxies on physical scales of up to 100 Mpc. And measurements from the total intensity radio emission of galaxy jets have the advantage of not being affected by effects such as scattering, extinction and Faraday Radiation, which may be an issue for other studies.

The presence of alignments and certain preferred orientations can shed light on the orientation and evolution of the galaxies, in relation to large-scale structures, and the motions in the primordial matter fluctuations that gave rise to the structure of the Universe.

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Astrophysicists find triple star system with 'hot Jupiter'

Astrophysicists find triple star system with 'hot Jupiter' | Amazing Science | Scoop.it

Crisp, clear images of a "hot Jupiter" system captured by a physicist were vital in determining that a newly found planet inhabits a three-star system, a phenomenon documented only a few times before.

 

Justin R. Crepp, Freimann Assistant Professor of Physics, was part of the team that discovered KELT-4Ab, a so-called "hot Jupiter" because it is a gas giant that orbits extremely close to one of the stars in its solar system. The discovery was published in The Astronomical Journal.

 

While the KELT, or Kilodegree Extremely Little Telescope, detected the likely presence of the planet now called KELT-4Ab about 685 light years from Earth, Crepp was able to capture crisp, clear images of the system, discovering that the planet was in fact a member of a triple star system -- one of only a few found to date.

 

The KELT monitors bright stars in large sections of the sky, searching for planets that orbit extremely closely. When the star KELT-A dimmed every few days, scientists believed they were witnessing an orbiting planet. Crepp was then asked to use the Keck Telescope to investigate and capture photos, and he wound up finding two additional stars in the process.

 

"I found that there was a dot nearby, which we believed to be a star, making this a binary system," Crepp says. "And then upon further review, I found that it was two dots. We wouldn't have realized that without these photos."

 

KELT-4Ab, about one and a half times the size of Jupiter, orbits the system's main star every three days. But the other two stars Crepp helped identify orbit each other once every 30 years while simultaneously orbiting the main star -- and the planet -- once every 4,000 years.

 

Four planets have been found in systems containing three stars, and Crepp has been involved with three of those discoveries. He and his students discovered the first two. "We are trying to learn how planets get to their final resting places in orbits around stars," Crepp says. "This discovery has implications for our understanding of planet formation and evolution."

 

Crepp says that until the mid-1990s, scientists believed that gas giants like Jupiter would be found far from the stars they orbit, much like Jupiter in our solar system. But when the first hot-Jupiter was discovered in 1995, it turned those assumptions on their heads. Since then, Crepp and others have been looking for these "hot Jupiters" to determine how they got there. The researchers believe the presence of multiple stars in a system could be a clue as to how planets finally settle into their orbits.

"We still think they formed far from their star, but then somehow migrated close to their stars. We also don't know how they stop migrating," Crepp says. "It is possible that companion stars drive the dynamics of planets such as to move the planets closer to the star."

 

With another gas giant found so close to its star and in a triple star system, Crepp says he and others can now start comparing and contrasting what they're seeing in other solar systems. "When you first find these, you're hunting and gathering. Once you have enough objects, we can start looking for patterns," Crepp says.

 

In a related project, Crepp is developing a tool that would be able to measure the "wobble" of stars as they gravitationally interact with their planets. He is also part of a NASA team that will soon be using the Transiting Exoplanet Survey Satellite (TESS) to find Earth-like planets orbiting in or near the habitable zone of their stars. TESS is expected to launch in fall 2017.

 

 

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Humongous black hole catches astronomers totally off guard

Humongous black hole catches astronomers totally off guard | Amazing Science | Scoop.it
Astronomers weren't expecting to find a supermassive black hole in this average-size galaxy, and they now may have to rethink their models.

 

One of the biggest black holes ever found sits in a cosmic backwater, like a towering skyscraper in a small town.

Astronomers have spotted a supermassive black hole containing 17 billion times the mass of the sun — only slightly smaller than the heftiest known black hole, which weighs in at a maximum of 21 billion solar masses — at the center of the galaxy NGC 1600.

 

That's a surprise, because NGC 1600, which lies 200 million light-years from Earth in the constellation Eridanus, belongs to an average-size galaxy group, and the monster black holes discovered to date tend to be found in dense clusters of galaxies. So researchers may have to rethink their ideas about where gigantic black holes reside, and how many of them might populate the universe, study team members said.

 

"This black hole is much bigger than we expected for the size of the galaxy or where this galaxy lives, the environment," said study co-author Chung-Pei Ma, an astronomer at the University of California, Berkeley.

 

"That's the puzzling part — or the intriguing part — of the result," she told Space.com. "There may be more NGC 1600s out there lurking at more ordinary sites, like small towns in the U.S. rather than Manhattan."Ma is head of the MASSIVE Survey, a multitelescope effort that began in 2014 to identify and catalogue the most massive nearby galaxies and black holes. NGC 1600 first showed up in the survey with data from the McDonald Observatory in Texas.

 

Although the initial observations weren't detailed enough to see the spectrum of light from the galaxy's center clearly, Ma and her colleagues could already tell that they were looking at something extraordinary: "It was a little bit like looking at a hurricane from very far away," she said. "We couldn't quite tell how big this hurricane was, this black hole was, but the hurricane was so big that we already started to feel the wind using this coarser data."

 

Suspecting they had spotted a very large black hole, study team members next investigated the elliptical galaxy using the northern half of the Gemini Observatory, twin telescopes situated in Hawaii and Chile. Gemini allowed them to probe the black hole's "sphere of influence," Ma said — the region where the black hole's mass held more sway than the overall galaxy's, where it was whipping the stars into action. They also scoped out the site with data from NASA's Hubble Space Telescope. The stars "were going so fast that the only way they could be travelling at this speed is if you had a 17-billion-solar-mass black hole at the center," she said.

 

The largest supermassive black hole ever found contains up to 21 billion times the mass of the sun, and resides in a more expected location: the incredibly dense Coma Cluster, which includes more than 1,000 identified galaxies. For comparison, the black hole lurking at the center of the Milky Way totals around 4 million solar masses.

 

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Origin of life: an artificial comet holds one missing piece

Origin of life: an artificial comet holds one missing piece | Amazing Science | Scoop.it

Researchers have for the first time shown that ribose, a sugar that is one of the building blocks of genetic material in living organisms, may have formed in cometary ice material. To obtain this result, scientists at the Institut de Chimie de Nice (CNRS/Université Nice Sophia Antipolis) carried out a highly detailed analysis of an artificial comet created by their colleagues at the Institut d'Astrophysique Spatiale (CNRS/Université Paris-Sud). Along with other teams, including one at the SOLEIL synchrotron, they propose the first realistic scenario for the formation of this key compound, which had never been detected in meteorites or cometary ices until now. Their findings, which shed new light on the emergence of life on Earth, are published in the journal Science dated 8 April 2016.

 

The genetic material of all living organisms on Earth, as well as of viruses, is made up of nucleic acids, DNA and RNA. RNA, which is considered more primitive, is thought to have been one of the first molecules characteristic of life to appear on Earth. Scientists have long wondered about the origin of these biological compounds. Some of them believe that the Earth was seeded by comets or asteroids that contained the basic building blocks needed to form such molecules. And indeed several amino acids (the components of proteins) and nitrogenous bases (one of the components of nucleic acids) have already been found in meteorites, as well as in artificial comets produced in the laboratory. However, ribose, the other key component of RNA, had never yet been detected in extraterrestrial material or created in the laboratory under 'astrophysical' conditions. Now, by simulating the evolution of the interstellar ice making up comets, French research teams have successfully obtained ribose, a key step in understanding the origin of RNA -- and therefore of life.

 

As a first step, an artificial comet was produced at the Institut d'Astrophysique Spatiale. By placing a representative mixture of water (H2O), methanol (CH3OH) and ammonia (NH3) in a high vacuum chamber at -- 200 °C, the astrophysicists simulated the formation of dust grains coated with ice, the raw material of comets. This material was irradiated with UV, as in the molecular clouds where these grains form. The sample was then warmed to room temperature, as in comets when they approach the Sun. Its composition was analyzed at the Institut de Chimie de Nice, optimizing an extremely sensitive and accurate method (multidimensional gas chromatography coupled with time-of-flight mass spectrometry). Several sugars were detected, including ribose. Their diversity and relative abundances suggest that they were formed from formaldehyde (a molecule found in space and on comets that forms in large quantities from methanol and water).

 

Although the existence of ribose in real comets remains to be confirmed, this discovery completes the list of the molecular building blocks of life that can be formed in interstellar ice. It also lends further support to the theory that comets are the source of the organic molecules that made life possible on Earth, and perhaps elsewhere in the Universe.

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NASA will let you walk on Mars using Microsoft's HoloLens

NASA will let you walk on Mars using Microsoft's HoloLens | Amazing Science | Scoop.it

NASA is teaming up with Microsoft to give you a glimpse of the Red Planet. A new exhibition called "Destination: Mars" will let visitors use Microsoft’s HoloLens augmented reality headsets to take a virtual stroll on Mars, alongside a "holographic" tour guide, astronaut Buzz Aldrin.

 

The exhibition, which will open this summer at NASA’s Kennedy Space Center Visitor Complex in Florida, uses OnSight, a mission operations tool co-developed by Microsoft and NASA’s Jet Propulsion Laboratory. Basically, OnSight will take the data and images collected by the Curiosity rover, which has been exploring Mars since August 2012, and use HoloLens to turn a room into the surface of the Red Planet for you to walk around.

 

OnSight is a tool that NASA scientists use to virtually explore Mars and make recommendations about where Curiosity should go next. For the first time, the exhibition will allow regular people to use that same tool and get "a glimpse of Mars as seen by mission scientists," NASA said in a press release.


Via Bonnie Bracey Sutton, John Purificati
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HD 20782b: Astronomers Discover Exoplanet with Highly Eccentric Orbit

HD 20782b: Astronomers Discover Exoplanet with Highly Eccentric Orbit | Amazing Science | Scoop.it
HD 20782b’s orbit closely resembles that of a comet, making it the most eccentric planet ever known.

 

According to a team of astronomers led by Dr. Stephen Kane of San Francisco State University, HD 20782b is a giant exoplanet located 117 light-years away in the constellation of Fornax.

The planet has a minimum mass twice that of Jupiter and orbits a star known as HD 20782, which is part of a wide binary star system with HD 20781.

 

HD 20782b has an orbital period of 597 days and an eccentricity of 0.96. This means that the planet moves in a nearly flattened ellipse, traveling a long path far from HD 20782 and then making a fast and furious slingshot around the star at its closest approach. “At the furthest point in its orbit, HD 20782b is separated from its star by 2.5 times the distance between the sun and Earth,” Dr. Kane explained. “At its closest approach, it ventures as close as 0.06 of that same Earth-Sun distance – much closer than Mercury orbits the Sun.”

 

He and co-authors were able to detect a signal of reflected light from HD 20782b – a ‘flash’ of starlight bouncing off its atmosphere as it made its closest orbital approach to its parent star. “The reflected light could tell researchers more about how the atmosphere of a planet like HD 20782b responds when it spends most of its time far away from its star, but then has a very close approach where it’s flash-heated by the star,” Dr. Kane said.

 

The percentage of light reflected from a planet is determined in part by the composition of its atmosphere. Planets shrouded in clouds full of icy particles, like Venus and Jupiter, for instance, are very reflective. But if a planet like Jupiter were to move too close to the Sun, the heat would remove the icy material in its clouds. “I

 

n some of the extrasolar, Jupiter-sized planets that tread short, circular orbits, this phenomenon does appear to strip the atmospheres of reflective particles, making the planets appear ‘dark.’ But in the case of HD 20782b, the atmosphere of the planet doesn’t have a chance to respond,” Dr. Kane said.

“The time it takes to swing around the star is so quick that there isn’t time to remove all the icy materials that make the atmosphere so reflective.”

 

HD 20782b might have an atmosphere with Jupiter-like, highly reflective cloud cover, according to the team.

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Astronomers see supernova shockwave for first time

Astronomers see supernova shockwave for first time | Amazing Science | Scoop.it

The shockwave generated by the explosion of an ageing giant star has been observed for the first time by an international team of astronomers.

 

The discovery, accepted for publishing in the Astrophysical Journal, will help scientists understand the life cycle of stars, said study co-author Brad Tucker of the Australian National University.

 

"This is the first time we've seen this in the normal visible colours, and we now know it happens," Dr Tucker said.

"The fundamental way we believe that core collapse happens is related to this shockwave happening. So the physics has been around … for decades and we've finally now been able to physically examine and test what's going on."

 

The team of scientists observed the earliest moments of two old stars exploding using the Kepler Space Telescope. They spotted the shockwave around the smaller of the two stars — a red supergiant over 270 times the radius of the Sun and 750 million light years away. As the star ran out of fuel it began collapsing and compressing on its central core.

 

"It's like packing in dirt," Dr Tucker said. "You keep pressing it till it's so dense you can't get it in anymore, and that's when you create a neutron star. "But you reach a limit when you can't pack it in anymore, and that force pushing in bounces back and it triggers a shockwave to go through the star, causing the star to actually blow up."

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Winds from Hell: Fastest winds ever have been discovered near a supermassive black hole

Winds from Hell: Fastest winds ever have been discovered near a supermassive black hole | Amazing Science | Scoop.it

The fastest winds ever seen at ultraviolet wavelengths have been discovered near a supermassive black hole. “This new ultrafast wind surprised us when it appeared at ultraviolet wavelengths, indicating it is racing away from the ravenous black hole at unprecedented speeds—almost like a bat out of hell,” says William Nielsen (Niel) Brandt, professor of astronomy and astrophysics and a professor of physics at Penn State. “We’re talking wind speeds of more than 200 million miles an hour, equivalent to a category 77 hurricane,” says Jesse Rogerson, who led the research as part of his efforts toward earning a PhD in the physics and astronomy department at York University in Canada.

 

The ultraviolet-wavelength winds are coming from the black hole’s quasar—the disk of hot gas that surrounds the black hole. Quasars form around supermassive black holes at the centers of massive galaxies. Quasars are bigger than Earth’s orbit around the Sun and hotter than the surface of the Sun, generating enough light to be seen across the observable universe. “An exciting discovery in recent years has been the realization that ultraviolet winds from quasars can both appear and disappear when viewed from Earth, depending on various conditions surrounding the black hole,” Brandt says.

 

“Black holes can have a mass that is billions of times larger than the Sun, mostly because they are messy eaters in a way, capturing any material that ventures too close,” says Patrick Hall, associate professor at York University. “But as matter spirals toward a black hole, some of it is blown away by the heat and light of the quasar. These are the winds that we are detecting.”

 

The researchers used data from the Sloan Digital Sky Survey (SDSS) to identify new outflows from quasars. After spotting about 300 examples, they selected about 100 for further exploration, collecting data with the Gemini Observatory’s twin telescopes in Hawaii and Chile. Much of the research is aimed at better understanding outflows from quasars and why they happen. “Quasar winds play an important role in galaxy formation,” Rogerson says.

 

“When galaxies form, these winds fling material outwards and deter the creation of stars. If such winds didn’t exist or were less powerful, we would see far more stars in big galaxies than we actually do. Hubble Space Telescope images of galaxies would look much different if quasar winds did not exist.”

 

The study is published in the Monthly Notices of the Royal Astronomical Society.

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Jupiter's X-ray Aurora is 100 times more energetic than Earth's Aurora Borealis

Jupiter's X-ray Aurora is 100 times more energetic than Earth's Aurora Borealis | Amazing Science | Scoop.it

Using data from NASA’s Chandra X-Ray Observatory, astronomers show that solar storms trigger Jupiter’s intense ‘Northern Lights’ by generating a new X-ray aurora that is eight times brighter than normal and hundreds of times more energetic than Earth’s aurora borealis.

 

It is the first time that Jupiter’s X-ray aurora has been studied when a giant storm from the Sun has arrived at the planet. The dramatic findings complement NASA’s Juno mission this summer which aims to understand the relationship between the two biggest structures in the solar system – the region of space controlled by Jupiter’s magnetic field (i.e. its magnetosphere) and that controlled by the solar wind.

 

“There’s a constant power struggle between the solar wind and Jupiter’s magnetosphere. We want to understand this interaction and what effect it has on the planet. By studying how the aurora changes, we can discover more about the region of space controlled by Jupiter’s magnetic field, and if or how this is influenced by the Sun. Understanding this relationship is important for the countless magnetic objects across the galaxy, including exoplanets, brown dwarfs and neutron stars,” explained lead author and PhD student at UCL Mullard Space Science Laboratory, William Dunn.

 

The Sun constantly ejects streams of particles into space in the solar wind. When giant storms erupt, the winds become much stronger and compress Jupiter’s magnetosphere, shifting its boundary with the solar wind two million kilometers through space. The study found that this interaction at the boundary triggers the high energy X-rays in Jupiter’s Northern Lights, which cover an area bigger than the surface of the Earth.

 

Published today in the Journal of Geophysical Research – Space Physics, the discovery comes as NASA’s Juno spacecraft nears Jupiter for the start of its mission this summer. Launched in 2011, Juno aims to unlock the secrets of Jupiter’s origin, helping us to understand how the solar system, including Earth, formed.

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Searching for aliens who already know we are here

Searching for aliens who already know we are here | Amazing Science | Scoop.it
Are we alone in the universe? To answer this question, astronomers have been using a variety of methods in the past decades to search for habitable planets and for the signals from extraterrestrial observers.

The first part of this venture has been highly successful: More than 2,000 planets around distant stars — so called exoplanets — have been found so far. The second part, the search for extraterrestrial intelligence (SETI), has not yet been successful.

Maybe the search strategy has not been optimized until now, said researchers from the Max Planck Institute for Solar System Research (MPS) in Göttingen, Germany, and from McMaster University in Canada. They suggest that future searches focus on that part of the sky in which distant observers can notice the yearly transit of Earth in front of the Sun.

Observers in this zone could have discovered Earth with the same techniques that are used by terrestrial astronomers to discover and characterize exoplanets. According to the researchers, the probability that extraterrestrials are already deliberately sending us signals is much higher in this part of the sky.

This strategy reduces the region that needs to be searched to about two thousandths of the sky, drastically reducing the amount of data to be analyzed.

When a planet passes in front of its host star, it causes a small transient dimming of the star. This so called transit can be measurable, depending on the size on the planet and the sensitivity of the instrument. In fact, the majority of the exoplanets known to us today have been discovered with this transit method. A similar technique, called transit spectroscopy, might enable astronomers in the future to scan the atmospheres of exoplanets for gaseous indicators of life.

In a first step, the two researchers identified the region in the sky from which one sees the transits less than half a solar radius from the center of the solar disk. The possible exoplanetary systems that offer this perspective are all located in a small strip in the sky, the projection of Earth’s orbit around the Sun (the ecliptic) onto the celestial sphere. The area of this strip amounts only to about two thousandths of the entire sky.

“The key point of this strategy is that it confines the search area to a very small part of the sky. As a consequence, it might take us less than a human life span to find out whether or not there are extraterrestrial astronomers who have found the Earth. They may have detected Earth’s biogenic atmosphere and started to contact whoever is home,” said René Heller from MPS.

Not every star is equally well suited as a home of extraterrestrial life. The more massive a star, the shorter is its life span. Yet, a long stellar life is considered a prerequisite for the development of higher life forms. Therefore the researchers compiled a list of stars that are not only in the advantageous part of the sky, but also offer good chances of hosting evolved forms of life, that is, intelligent life. The researchers compiled a list of 82 nearby Sun-like stars that satisfy their criteria. This catalog can now serve as an immediate target list for SETI initiatives.
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Guillaume Decugis's curator insight, March 19, 4:21 PM

Learning the lessons from exoplanet search to transform the SETI program could lead to a much more focused search. And therefore more successful. Looking at the limited area of the sky where aliens are the most likely to be listening to us already... as they might track us the way we track exoplanets. 

Stéphanie Guillaume's curator insight, March 21, 9:50 AM

A la recherche d'extra terrestres qui savent déjà que nous sommes là...

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What Happened to Early Mars' Atmosphere? New Study Eliminates One Theory

What Happened to Early Mars' Atmosphere? New Study Eliminates One Theory | Amazing Science | Scoop.it

Scientists may be closer to solving the mystery of how Mars changed from a world with surface water billions of years ago to the arid Red Planet of today. A new analysis of the largest known deposit of carbonate minerals on Mars suggests that the original Martian atmosphere may have already lost most of its carbon dioxide by the era of valley network formation.

 

"The biggest carbonate deposit on Mars has, at most, twice as much carbon in it as the current Mars atmosphere," said Bethany Ehlmann of the California Institute of Technology and NASA Jet Propulsion Laboratory, both in Pasadena. "Even if you combined all known carbon reservoirs together, it is still nowhere near enough to sequester the thick atmosphere that has been proposed for the time when there were rivers flowing on the Martian surface."

 

Carbon dioxide makes up most of the Martian atmosphere. That gas can be pulled out of the air and sequestered or pulled into the ground by chemical reactions with rocks to form carbonate minerals. Years before the series of successful Mars missions, many scientists expected to find large Martian deposits of carbonates holding much of the carbon from the planet's original atmosphere. Instead, these missions have found low concentrations of carbonate distributed widely, and only a few concentrated deposits. By far the largest known carbonate-rich deposit on Mars covers an area at least the size of Delaware, and maybe as large as Arizona, in a region called Nili Fossae.

 

Christopher Edwards, a former Caltech researcher now with the U.S. Geological Survey in Flagstaff, Arizona, and Ehlmann reported the findings and analysis in a paper posted online by the journal Geology. Their estimate of how much carbon is locked into the Nili Fossae carbonate deposit uses observations from numerous Mars missions, including the Thermal Emission Spectrometer (TES) on NASA's Mars Global Surveyor orbiter, the mineral-mapping Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and two telescopic cameras on NASA's Mars Reconnaissance Orbiter, and the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter.

 

Edwards and Ehlmann compare their tally of sequestered carbon at Nili Fossae to what would be needed to account for an early Mars atmosphere dense enough to sustain surface waters during the period when flowing rivers left their mark by cutting extensive river-valley networks. By their estimate, it would require more than 35 carbonate deposits the size of the one examined at Nili Fossae. They deem it unlikely that so many large deposits have been overlooked in numerous detailed orbiter surveys of the planet. While deposits from an even earlier time in Mars history could be deeper and better hidden, they don't help solve the thin-atmosphere conundrum at the time the river-cut valleys formed.

 

The modern Martian atmosphere is too tenuous for liquid water to persist on the surface. A denser atmosphere on ancient Mars could have kept water from immediately evaporating. It could also have allowed parts of the planet to be warm enough to keep liquid water from freezing. But if the atmosphere was once thicker, what happened to it? One possible explanation is that Mars did have a much denser atmosphere during its flowing-rivers period, and then lost most of it to outer space from the top of the atmosphere, rather than by sequestration in minerals.

 

"Maybe the atmosphere wasn't so thick by the time of valley network formation," Edwards said. "Instead of Mars that was wet and warm, maybe it was cold and wet with an atmosphere that had already thinned. How warm would it need to have been for the valleys to form? Not very. In most locations, you could have had snow and ice instead of rain. You just have to nudge above the freezing point to get water to thaw and flow occasionally, and that doesn't require very much atmosphere."

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Stephen Hawking backs 'Starshot' plan to get probes to Alpha Centauri in your lifetime

Stephen Hawking backs 'Starshot' plan to get probes to Alpha Centauri in your lifetime | Amazing Science | Scoop.it

The concept of exploring other star systems with probes (and not just telescopes) has proven elusive for one good reason: even the fastest spacecraft would take 30,000 years just to reach Alpha Centauri, our closest neighboring star. However, investor and space project enthusiast Yuri Milner thinks it's possible to do better. He and physicist Stephen Hawking have launched Breakthrough Starshot, a $100 million program that aims to get probes to Alpha Centauri within a generation. If all goes well, the observers would reach the relatively close-by system (4.4 light years away) within 20 years of leaving Earth.

 

The current proposal would revolve around thousands of tiny "nanocrafts" that would use lightsails as propulsion. If you hit those sails with an sufficiently high-powered laser (Breakthrough is talking up to 100 gigawatts), the probes could travel up to 20 percent of the speed of light. That breakneck pace would prevent them from staying in the Alpha Centauri system for long, but that would be enough to collect data about the star's alien worlds and send it back. Humanity would hopefully get that information 4 years later by using the same laser equipment that launched the probes in the first place.

 

Starshot revolves around a very open strategy that would rely on public scientific data and allow anyone to contribute ideas. However, there are are still some big "ifs" involved. The program will only work if it can build the nanocrafts, if laser technology is good enough to reach the intended speeds, if enough of the craft can survive the journey without being waylaid by cosmic dust or similar obstacles. Needless to say, though, it's a big deal if everything comes together -- interstellar exploration wouldn't have to wait for your descendants.

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Measurement of Universe's expansion rate creates cosmological puzzle

Measurement of Universe's expansion rate creates cosmological puzzle | Amazing Science | Scoop.it

The most precise measurement ever made of the current rate of expansion of the Universe has produced a value that appears incompatible with measurements of radiation left over from the Big Bang1. If the findings are confirmed by independent techniques, the laws of cosmology might have to be rewritten.

 

 

This might even mean that dark energy — the unknown force that is thought to be responsible for the observed acceleration of the expansion of the Universe — has increased in strength since the dawn of time. “I think that there is something in the standard cosmological model that we don't understand,” says astrophysicist Adam Riess, a physicist at Johns Hopkins University in Baltimore, Maryland, who co-discovered dark energy in 1998 and led the latest study.

 

Kevork Abazajian, a cosmologist at the University of California, Irvine, who was not involved in the study, says that the results have the potential of “becoming transformational in cosmology”.

 

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Laser cloaking device could help us to hide from aliens

Laser cloaking device could help us to hide from aliens | Amazing Science | Scoop.it

Two astronomers at Columbia University in New York suggest humanity could use lasers to conceal the Earth from searches by advanced extraterrestrial civilisations. Professor David Kipping and graduate student Alex Teachey make the proposal in a paper in Monthly Notices of the Royal Astronomical Society.

Several prominent scientists, including Stephen Hawking, have cautioned against humanity broadcasting our presence to intelligent life on other planets. Other civilisations might try to find Earth-like planets using the same techniques we do, including looking for the dip in light when a planet moves directly in front of the star it orbits.

 

These events – transits – are the main way that the Kepler mission and similar projects search for planets around other stars. So far Kepler alone has confirmed more than 1,000 planets using this technique, with tens of these worlds similar in size to the Earth. Kipping and Teachey speculate that alien scientists may use this approach to locate our planet, which will be clearly in the 'habitable zone' of the Sun, where the temperature is right for liquid water, and so be a promising place for life.

 

Hawking and others are concerned that extraterrestrials might wish to take advantage of the Earth’s resources, and that their visit, rather than being benign, could be as devastating as when Europeans first travelled to the Americas. The two authors of the new study suggest that transits could be masked by controlled laser emission, with the beam directed at the star where the aliens might live. When the transit takes place, the laser would be switched on to compensate for the dip in light.

 

According to the authors, emitting a continuous 30 MW laser for about 10 hours, once a year, would be enough to eliminate the transit signal, at least in visible light. The energy needed is comparable to that collected by the International Space Station in a year. A chromatic cloak, effective at all wavelengths, is more challenging, and would need a large array of tuneable lasers with a total power of 250 MW.

 

"Alternatively, we could cloak only the atmospheric signatures associated with biological activity, such as oxygen, which is achievable with a peak laser power of just 160 kW per transit. To another civilisation, this should make the Earth appear as if life never took hold on our world", said Alex.

 

As well as cloaking our presence, the lasers could also be used to modify the way the light from the Sun drops during a transit to make it obviously artificial, and thus broadcast our existence. The authors suggest that we could transmit information along the laser beams at the same time, providing a means of communication.

 

David comments: "There is an ongoing debate as to whether we should advertise ourselves or hide from advanced civilisations potentially living on planets elsewhere in the Galaxy. Our work offers humanity a choice, at least for transit events, and we should think about what we want to do."

 

Given that humanity is already capable of modifying transit signals, it may just be that aliens have had the same thought. The two scientists propose that the Search for Extraterrestrial Intelligence (SETI), which mostly currently looks for alien radio signals, could be broadened to search for artificial transits.

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Hot super-Earths stripped by host stars: 'Cooked' planets shrink due to radiation

Hot super-Earths stripped by host stars: 'Cooked' planets shrink due to radiation | Amazing Science | Scoop.it

Astrophysicists at the University of Birmingham have used data from the NASA Kepler space telescope to discover a class of extrasolar planets whose atmospheres have been stripped away by their host stars. According to the study, planets with gaseous atmospheres that lie very close to their host stars are bombarded by a torrent of high-energy radiation. Due to their proximity to the star, the heat that the planets suffer means that their 'envelopes' have been blown away by intense radiation. This violent 'stripping' occurs in planets that are made up of a rocky core with a gaseous outer layer.

 

The scientists used asteroseismology to characterize the stars and their planets to levels of accuracy not achieved before for these systems. Asteroseismology uses the natural resonances of stars to reveal their properties and inner structures. The results of the study have important implications for understanding how stellar systems, like our own solar system, and their planets, evolve over time and the crucial role played by the host star.

 

Dr Guy Davies, from the University of Birmingham's School of Physics and Astronomy, said: 'For these planets it is like standing next to a hairdryer turned up to its hottest setting. There has been much theoretical speculation that such planets might be stripped of their atmospheres. We now have the observational evidence to confirm this, which removes any lingering doubts over the theory.'

 

Dr Davies added: 'Our results show that planets of a certain size that lie close to their stars are likely to have been much larger at the beginning of their lives. Those planets will have looked very different.' Scientists expect to discover and characterize many more of these 'stripped systems' using a new generation of satellites, including the NASA TESS Mission which will be launched next year.

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Water ice detected at the surface of a distant star's disk

Water ice detected at the surface of a distant star's disk | Amazing Science | Scoop.it
(Phys.org)—A team of Japanese astronomers has recently discovered water ice at the surface of a distant star's disk. Using the Near-Infrared Coronagraphic Imager (NICI) installed on the Gemini South Telescope in Chile

 

HD 100546 is a 10 million-year-old star located some 320 light years from the Earth. It is accompanied by a fairly flat circumstellar disk in an advanced evolutionary state residing at a distance of 0.2 to four AU, and again from 13 to a few hundred AU from the star. The Hubble Space Telescope revealed that the disk features some complex spiral patterns. However, the nature and origin of these patterns remains uncertain.

 

The star was observed using NICI on Mar. 31, 2012. This instrument is a coronagraphic camera designed to survey for and image large, extra-solar gaseous planets. It allows astronomers to search for large Jupiter planets around nearby stars by spectrally differencing two images taken in or next to strong, near-infrared methane features found in the atmosphere of large, Jovian-type planets.

 

The scientists extracted the scattered light spectra of different regions of the protoplanetary disk around HD 100546. Scattered light observations complement thermal observations and constrain models based on spectroscopic data. NICI helped them unveil the 3.1 µm absorption feature in the scattered light spectrum of the observed disk. They link this feature with the presence of water ice grains.

 

According to the research team, the shallowness of this ice absorption feature can be explained by the loss of ice grains at the disk surface. "In almost all the regions, relatively shallow three µm absorption feature is present in their spectra likely due to water ice grains, indicating that the water ice grains present in the disk surface," the paper reads.

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Gems that fall from Space: Pallasite peridot, faceted moldavite, wire-wrapped tektite, and others

Gems that fall from Space: Pallasite peridot, faceted moldavite, wire-wrapped tektite, and others | Amazing Science | Scoop.it

Several different extraterrestrial materials can be used as gems. Pallasite peridot, faceted moldavite, wire-wrapped tektite, desert glass pendants, iron meteorites.

 

Rocks that fall from the sky have frightened and fascinated people throughout history. They immediately generate curiosity and have a scientific significance. They are made of extremely rare materials that interest scientists, collectors, and curious people alike.

Many meteorites and impactites are small enough and attractive enough to be used as gems in the same condition in which they fell from the sky. Iron meteorites are alloys of iron and nickel that can be cut and polished into beautiful gems or fashioned into the metal parts of jewelry. Pallasites are stony-iron meteorites that contain colorful peridot (olivine) crystals that can be cut into gems. Impactites are often colorful glasses that can be faceted, cut into cabochons, or carved into small sculptures.

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NASA's Spitzer finds two-faced alien planet having solid and liquid surfaces

NASA's Spitzer finds two-faced alien planet having solid and liquid surfaces | Amazing Science | Scoop.it
Observations from NASA's Spitzer Space Telescope have led to the first temperature map of a super-Earth planet -- a rocky planet nearly two times as big as ours.

 

Observations from NASA's Spitzer Space Telescope have led to the first temperature map of a super-Earth planet -- a rocky planet nearly two times as big as ours. The map reveals extreme temperature swings from one side of the planet to the other, and hints that a possible reason for this is the presence of lava flows.

"Our view of this planet keeps evolving," said Brice Olivier Demory of the University of Cambridge, England, lead author of a new report appearing in the March 30 issue of the journal Nature. "The latest findings tell us the planet has hot nights and significantly hotter days. This indicates the planet inefficiently transports heat around the planet. We propose this could be explained by an atmosphere that would exist only on the day side of the planet, or by lava flows at the planet surface."

 

The toasty super-Earth 55 Cancri e is relatively close to Earth at 40 light-years away. It orbits very close to its star, whipping around it every 18 hours. Because of the planet's proximity to the star, it is tidally locked by gravity just as our moon is to Earth. That means one side of 55 Cancri, referred to as the day side, is always cooking under the intense heat of its star, while the night side remains in the dark and is much cooler.

 

"Spitzer observed the phases of 55 Cancri e, similar to the phases of the moon as seen from the Earth. We were able to observe the first, last quarters, new and full phases of this small exoplanet," said Demory. "In return, these observations helped us build a map of the planet. This map informs us which regions are hot on the planet."

 

Spitzer stared at the planet with its infrared vision for a total of 80 hours, watching it orbit all the way around its star multiple times. These data allowed scientists to map temperature changes across the entire planet. To their surprise, they found a dramatic temperature difference of 2340 degrees Fahrenheit (1,300 Kelvin) from one side of the planet to the other. The hottest side is nearly 4,400 degrees Fahrenheit (2,700 Kelvin), and the coolest is 2,060 degrees Fahrenheit (1,400 Kelvin).

 

The fact Spitzer found the night side to be significantly colder than the day side means heat is not being distributed around the planet very well. The data argues against the notion that a thick atmosphere and winds are moving heat around the planet as previously thought. Instead, the findings suggest a planet devoid of a massive atmosphere, and possibly hint at a lava world where the lava would become hardened on the night side and unable to transport heat.


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Astronomers see unprecedented detail of inner portion of protoplanetary disk

Astronomers see unprecedented detail of inner portion of protoplanetary disk | Amazing Science | Scoop.it
Astronomers have discovered details of the inner, thickest portion of a dusty disk surrounding a young star and provided new insight on the earliest stages of planet formation.

 

New images of a young star made with the Karl G. Jansky Very Large Array (VLA) reveal what scientists think may be the very earliest stages in the formation of planets. The scientists used the VLA to see unprecedented detail of the inner portion of a dusty disk surrounding the star, some 450 light-years from Earth.

 

The star and its disk were studied in 2014 with the Atacama Large Millimeter/submillimeter Array (ALMA), which produced what astronomers then called the best image ever of planet formation in progress. The ALMA image showed gaps in the disk, presumably caused by planet-like bodies sweeping out the dust along their orbits. This image, showing in real life what theorists had proposed for years, was surprising, however, because the star, called HL Tau, is only about a million years old -- very young by stellar standards.

 

The ALMA image showed details of the system in the outer portions of the disk, but in the inner portions of the disk, nearest to the young star, the thicker dust is opaque to the short radio wavelengths received by ALMA. To study this region, astronomers turned to the VLA, which receives longer wavelengths. Their VLA images show that region better than any previous studies.

 

The new VLA images revealed a distinct clump of dust in the inner region of the disk. The clump, the scientists said, contains roughly 3 to 8 times the mass of the Earth.

"We believe this clump of dust represents the earliest stage in the formation of protoplanets, and this is the first time we've seen that stage," said Thomas Henning, of the Max Planck Institute for Astronomy (MPIA).

 

"This is an important discovery, because we have not yet been able to observe most stages in the process of planet formation," said Carlos Carrasco-Gonzalez from the Institute of Radio Astronomy and Astrophysics (IRyA) of the National Autonomous University of Mexico (UNAM). "This is quite different from the case of star formation, where, in different objects, we have seen stars in different stages of their life cycle. With planets, we haven't been so fortunate, so getting a look at this very early stage in planet formation is extremely valuable," he added.

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Beyond today's crowdsourced science to tomorrow's citizen science cyborgs

Beyond today's crowdsourced science to tomorrow's citizen science cyborgs | Amazing Science | Scoop.it
Computers are getting better and better at the jobs that previously made sense for researchers to outsource to citizen scientists. But don't worry: there's still a role for people in these projects.

 

We’re now entering an era in which machines are starting to become competitive with humans in terms of analyzing images, a task previously reserved for human citizen scientists clicking away at galaxies, climate records or snapshots from the Serengeti. This landscape is completely different from when I was a graduate student just a decade ago – then, the machines just weren’t quite up to scratch in many cases. Now they’re starting to outperform people in more and more tasks.

 

Rather than replacing citizen scientists, though, machines can help them – and it could not have come at a better time. Scientific experiments are flooding researchers with data: astronomers needed the help of the Internet to classify one million galaxies from an astronomical survey that took place in the 1990s and 2000s. Soon telescopes like the Large Synoptic Sky Telescope will give us images of billions of galaxies in addition to supernovae, asteroids and other strange things that go bump in the night.

 

How will astronomers be able to deal with all these data, many of which are time-sensitive? After all, if something goes “bump” and fades quickly, we’d want to try to study it more before it disappears forever. That’s where the machines can really help us: deep minds can scale up to process large data sets if we just give them sufficient processing power and memory.

 

But the machines still need help – our help! One of the biggest problems for deep neural nets is that they require large training sets, examples of data (say, images of galaxies) which have already been carefully and accurately classified. This is one way in which the citizen scientists will be able to contribute: train the machines by providing high-quality training sets so the machines can then go off and deal with the rest of the data.

There’s another way citizen scientists will be able to pitch in: by helping us identify the weird things out there we don’t know about yet, the proverbial Rumsfeldian “unknown unknowns.” Machines can struggle with noticing unusual or unexpected things, whereas humans excel at it.

 

Having the citizen scientists help the machines spot these unexpected things in the data would complement the machines’ ability to churn through huge data sets. If a machine got confused by something, or just wanted some extra feedback, it could kick the object back to a human for help, and then update itself to deal with similar things in the future. This could find applications not just in astrophysics, but in many other fields of science, from surveys of the sea floor to archives in museums, and the detectors of particle accelerators.

 

So envision a future where a smart system for analyzing large data sets diverts some small percentage of the data to human citizen scientists to help train the machines. The machines then go through the data, occasionally spinning off some more objects to the humans to improve machine performance as time goes on. If the machines then encounter something odd or unexpected, they pass it on to the citizen scientists for evaluation. Thus, humans and machines will form a true collaboration: citizen science cyborgs.

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A new view of the X-ray sky

A new view of the X-ray sky | Amazing Science | Scoop.it

Scientists at the Max Planck Institute for Extraterrestrial Physics (MPE) have revisited the all-sky survey carried out by the ROSAT satellite, to create a new image of the sky at X-ray wavelengths. Along with this a revised and extended version of the catalogue of bright and faint point-like sources will be released. The now published "2RXS catalogue" provides the deepest and cleanest X-ray all-sky survey to date, which will only be superseded with the launch of the next generation X-ray survey satellite, eROSITA, currently being completed at MPE.

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Young sun-like star shows a magnetic field was critical for life on the early Earth

Young sun-like star shows a magnetic field was critical for life on the early Earth | Amazing Science | Scoop.it

Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, and a blanketing atmosphere. But life thrived thanks to another necessary ingredient: the presence of a magnetic field.

 

"To be habitable, a planet needs warmth, water, and it needs to be sheltered from a young, violent Sun," says lead author Jose-Dias Do Nascimento of the Harvard-Smithsonian Center for Astrophysics (CfA) and University of Rio G. do Norte (UFRN), Brazil.

 

Kappa Ceti, located 30 light-years away in the constellation Cetus, the Whale, is remarkably similar to our Sun but younger. The team calculates an age of only 400-600 million years old, which agrees with the age estimated from its rotation period (a technique pioneered by CfA astronomer Soren Meibom). This age roughly corresponds to the time when life first appeared on Earth. As a result, studying Kappa Ceti can give us insights into the early history of our solar system.

 

Like other stars its age, Kappa Ceti is very magnetically active. Its surface is blotched with many giant starspots, like sunspots but larger and more numerous. It also propels a steady stream of plasma, or ionized gases, out into space. The research team found that this stellar wind is 50 times stronger than our Sun's solar wind.

 

Such a fierce stellar wind would batter the atmosphere of any planet in the habitable zone, unless that planet was shielded by a magnetic field. At the extreme, a planet without a magnetic field could lose most of its atmosphere. In our solar system, the planet Mars suffered this fate and turned from a world warm enough for briny oceans to a cold, dry desert.

 

The team modeled the strong stellar wind of Kappa Ceti and its effect on a young Earth. The early Earth's magnetic field is expected to have been about as strong as it is today, or slightly weaker. Depending on the assumed strength, the researchers found that the resulting protected region, or magnetosphere, of Earth would be about one-third to one-half as large as it is today.

 

"The early Earth didn't have as much protection as it does now, but it had enough," says Do Nascimento.


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Hubble captures star cluster 30 MILLION times brighter than the sun

Hubble captures star cluster 30 MILLION times brighter than the sun | Amazing Science | Scoop.it
The cluster - named R136 - is only a few light years across and is in the Tarantula Nebula within the Large Magellanic Cloud - a satellite galaxy of our own Milky Way.

The team said the young cluster hosts many extremely massive, hot and luminous stars whose energy is mostly radiated in the ultra violet - which is why the scientists used Hubble to probe the ultraviolet emission of the cluster.

It includes nine monster stars which are more than 100 times the mass of the Sun and dozens of stars exceeding 50 solar masses.

None of the stars identified have unseated R126a1, also in the Tarantula Nebula, as the most massive star in the known universe at more than 250 solar masses.

The team combined images taken with the Wide Field Camera 3 on Hubble with the unprecedented ultraviolet spatial resolution of its Space Telescope Imaging Spectrograph (STIS). 
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