Strong irradiation from the host star can cause planets known as mini-Neptunes in the habitable zone to shed their gaseous envelopes and become potentially habitable worlds.Credit: Rodrigo Luger / NASA imagesExcerpt from sciencedaily.com Two ph...
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The Lunatic Piran found abandoned Jure Stwerk at the Helm ...
Images of the dwarf planet Ceres, which were taken by the Dawn spacecraft, reveal a mysterious white spot that reflects more sunlight. NASA scientists are not yet certain what this is but they have a hypothesis.Excerpt from techtimes.comA series of ...
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| Cassiopeia: A supernova remnant |
Excerpt from news.discovery.com
One of the least likely places you might think astronomers would learn about ancient supernovae is at the bottom of the ocean, but in new research scientists have done just that.
Through the careful analysis of ocean sediment, tiny particles that originated from deep space have settled on the seabed, locking the chemical secrets to supernova processes that would have otherwise remained a mystery.
“Small amounts of debris from these distant explosions fall on the earth as it travels through the galaxy,” said lead researcher Anton Wallner, of the Australian National University. “We’ve analyzed galactic dust from the last 25 million years that has settled on the ocean and found there is much less of the heavy elements such as plutonium and uranium than we expected.”
Supernovae are powerful explosions triggered when massive stars reach the ends of their lives. During these powerful events, many elements are forged, including elements that are essential for life to thrive — such as iron, potassium and iodine.
Wallner and his team studied samples of sediment from the bottom of a stable area at the bottom of the Pacific Ocean. But when measuring the quantities of plutonium-244, a radioisotope that is produced by supernovae, they found something strange in their results — there was 100 time less plutonium-244 than predicted.
Plutonium-244 has a half-life of 81 million years, making it an excellent indicator of the number of supernovae that have exploded nearby in recent galactic history. “So any plutonium-244 that we find on earth must have been created in explosive events that have occurred more recently, in the last few hundred million years,” said Wallner.
But the fact that there is less recent deposition of the heaviest of elements, despite the fact that we know supernovae have erupted nearby, suggests a different formation mechanism may be responsible for plutonium-244 and elements like it.
“It seems that these heaviest elements may not be formed in standard supernovae after all,” concludes Wallner. “It may require rarer and more explosive events such as the merging of two neutron stars to make them.”
Excerpt from space.com
Galaxies come in all different shapes and sizes, and a massive new simulation of the universe has captured that galactic variety with more accuracy than any simulation before it, according to a new study.
Using a simulation called EAGLE (Evolution and Assembly of GaLaxies and their Environments), researchers from multiple institutes in Europe have cooked up a dazzling simulation of the universe that contains tens of thousands of galaxies.
A sample of the new simulation can be seen in the video above. It shows the evolution of the universe in a region 25 megaparsecs cubed (about 81 million light years).
"This is really a staggering success, I think it's fair to say," Rob Crain from Liverpool John Moores University and a member of the group that built EAGLE, told Space.com. The researchers are part of a collaboration called the Virgo Consortium for Cosmological Supercomputer Simulations. "Go to our previous generation of simulations, and the galaxies all look like big spherical blobs. Now they form disks and bars and irregular galaxies and different types of ellipticals."
A computer simulation is like a recipe for the universe. Scientists have to start with a list of ingredients and instructions — which actually means a description of the physics that underlie the current universe. While many simulations can recreate the major cosmic ingredients (like stars and galaxies), the subtleties are harder to achieve (like the shape, mass and distribution of those stars and galaxies).
The bottom right corner of the screen shows the time after the Big Bang (denoted by "t"). In the early universe, matter is dispersed and hazy, but gradually coalesces into a sort of web, with long strands of material connecting nodes where galaxies are clustered. At 1:06, the simulation starts again from the beginning and shows the three major components of the model: dark matter (labeled as CDM), gas (the red globs are gas clouds where stars are often born), and stars. The full EAGLE simulation contains an area 100 megaparsecs cubed.
One goal of the EAGLE group was to produce a simulation large enough that it contained all types of galaxies seen in the universe. This allows the researchers to find out if the physics they programmed into EAGLE are accurate for all galaxies, and if they produce the correct number of galaxies in the universe.
Schaye said the picture of the universe created by the EAGLE simulation "is not perfect, but for astronomers the level of agreement is very impressive. It seems we have the main ingredients in place."
Excerpt from earthsky.org
Admit it. You’ve probably got a pair of binoculars lying around your house somewhere. They may be perfect – that’s right, perfect – for beginning stargazing. Follow the links below to learn more about the best deal around for people who want to get acquainted with the night sky: a pair of ordinary binoculars.
1. Binoculars are a better place to start than telescopes
2. Start with a small, easy-to-use size
3. First, view the moon with binoculars.
4. Move on to viewing planets with binoculars.
5. Use your binoculars to explore inside our Milky Way.
6. Use your binoculars to peer beyond the Milky Way.
1. Binoculars are a better place to start than telescopes. The fact is that most people who think they want to buy a telescope would be better off using binoculars for a year or so instead. That’s because first-time telescope users often find themselves completely confused – and ultimately put off – by the dual tasks of learning the use a complicated piece of equipment (the ‘scope) while at the same time learning to navigate an unknown realm (the night sky).
Beginning stargazers often find that an ordinary pair of binoculars – available from any discount store – can give them the experience they’re looking for. After all, in astronomy, magnification and light-gathering power let you see more of what’s up there. Even a moderate form of power, like those provided by a pair of 7×50 binoculars, reveals 7 times as much information as the unaided eye can see.
You also need to know where to look. Many people start with a planisphere as they begin their journey making friends with the stars. You can purchase a planisphere at the EarthSky store. Also consider our Astronomy Kit, which has a booklet on what you can see with your binoculars.
2. Start with a small, easy-to-use size. Don’t buy a huge pair of binoculars to start with! Unless you mount them on a tripod, they’ll shake and make your view of the heavens shakey, too. The video above – from ExpertVillage – does a good job summing up what you want. And in case you don’t want to watch the video, the answer is that 7X50 binoculars are optimum for budding astronomers. You can see a lot, and you can hold them steadily enough that jitters don’t spoil your view of the sky. Plus they’re very useful for daylight pursuits, like birdwatching. If 7X50s are too big for you – or if you want binoculars for a child – try 7X35s.
February 24, 2014 moon with earthshine by Greg Diesel Landscape Photography.
You’ll want to start your moon-gazing when the moon is just past new – and visible as a waxing crescent in the western sky after sunset. At such times, you’ll have a beautiful view of earthshine on the moon. This eerie glow on the moon’s darkened portion is really light reflected from Earth onto the moon’s surface. Be sure to turn your binoculars on the moon at these times to enhance the view.
Each month, as the moon goes through its regular phases, you can see the line of sunrise and sunset on the moon progress across the moon’s face. That’s just the line between light and dark on the moon. This line between the day and night sides of the moon is called the terminator line. The best place to look at the moon from Earth – using your binoculars – is along the terminator line. The sun angle is very low in this twilight zone, just as the sun is low in our sky around earthly twilight. So, along the terminator on the moon, lunar features cast long shadows in sharp relief.
You can also look in on the gray blotches on the moon called maria, named when early astronomers thought these lunar features were seas. The maria are not seas, of course, and instead they’re now thought to have formed 3.5 billion years ago when asteroid-sized rocks hit the moon so hard that lava percolated up through cracks in the lunar crust and flooded the impact basins. These lava plains cooled and eventually formed the gray seas we see today.
The white highlands, nestled between the maria, are older terrain pockmarked by thousands of craters that formed over the eons. Some of the larger craters are visible in binoculars. One of them, Tycho, at the six o’clock position on the moon, emanates long swatches of white rays for hundreds of miles over the adjacent highlands. This is material kicked out during the Tycho impact 2.5 million years ago.
Photo of Jupiter’s moons by Earthsky Facebook friend Carl Galloway. Thank you Carl! The four major moons of Jupiter are called Io, Europa, Ganymede and Callisto. This is a telescopic view, but you can glimpse one, two or more moons through your binoculars, too.
4. Move on to viewing planets with binoculars. Here’s the deal about planets. They move around, apart from the fixed stars. They are wanderers, right?
You can use our EarthSky Tonight page to locate planets visible around now. Notice if any planets are mentioned in the calendar on the Tonight page, and if so click on that day’s link. On our Tonight page, we feature planets on days when they’re easily identifiable for some reason – for example, when a planet is near the moon. So our Tonight page calendar can help you come to know the planets, and, as you’re learning to identify them, keep your binoculars very handy. Binoculars will enhance your view of a planet near the moon, for example, or two planets near each other in the twilight sky. They add a lot to the fun!
Below, you’ll find some more simple ideas on how to view planets with your binoculars.
Mercury and Venus. These are both inner planets. They orbit the sun closer than Earth’s orbit. And for that reason, both Mercury and Venus show phases as seen from Earth at certain times in their orbit – a few days before or after the planet passes between the sun and Earth. At such times, turn your binoculars on Mercury or Venus. Good optical quality helps here, but you should be able to see them in a crescent phase. Tip: Venus is so bright that its glare will overwhelm the view. Try looking in twilight instead of true darkness.
Mars. Mars – the Red Planet – really does look red, and using binoculars will intensify the color of this object (or of any colored star). Mars also moves rapidly in front of the stars, and it’s fun to aim your binoculars in its direction when it’s passing near another bright star or planet.
Jupiter. Now on to the real action! Jupiter is a great binocular target, even for beginners. If you are sure to hold your binoculars steadily as you peer at this bright planet, you should see four bright points of light near it. These are the Galilean Satellites – four moons gleaned through one of the first telescopes ever made, by the Italian astronomer Galileo. Note how their relative positions change from night to night as each moon moves around Jupiter in its own orbit.
Saturn.Although a small telescope is needed to see Saturn’s rings, you can use your binoculars to see Saturn’s beautiful golden color. Experienced observers sometimes glimpse Saturn’s largest moon Titan with binoculars. Also, good-quality high-powered binoculars – mounted on a tripod – will show you that Saturn is not round. The rings give it an elliptical shape.
Uranus and Neptune. Some planets are squarely binocular and telescope targets. If you’re armed with a finder chart, two of them, Uranus and Neptune, are easy to spot in binoculars. Uranus might even look greenish, thanks to methane in the planet’s atmosphere. Once a year, Uranus is barely bright enough to glimpse with the unaided eye . . . use binoculars to find it first. Distant Neptune will always look like a star, even though it has an atmosphere practically identical to Uranus.
There are still other denizens of the solar system you can capture through binocs. Look for the occasional comet, which appears as a fuzzy blob of light. Then there are the asteroids – fully 12 of them can be followed with binoculars when they are at their brightest. Because an asteroid looks star-like, the secret to confirming its presence is to sketch a star field through which it’s passing. Do this over subsequent nights; the star that changes position relative to the others is our solar system interloper.
Pleiades star cluster, also known as the Seven Sisters
5. Use your binoculars to explore inside our Milky Way. Binoculars can introduce you to many members of our home galaxy. A good place to start is with star clusters that are close to Earth. They cover a larger area of the sky than other, more distant clusters usually glimpsed through a telescope.
Beginning each autumn and into the spring, look for a tiny dipper-like cluster of stars called the Pleiades. The cluster – sometimes also called the Seven Sisters – is noticeable for being small yet distinctively dipper-like. While most people say they see only six stars here with the unaided eye, binoculars reveal many more stars, plus a dainty chain of stars extending off to one side. The Pleiades star cluster is looks big and distinctive because it’s relatively close – about 400 light years from Earth. This dipper-shaped cluster is a true cluster of stars in space. Its members were born around the same time and are still bound by gravity. These stars are very young, on the order of 20 million years old, in contrast to the roughly five billion years for our sun.
Stars in a cluster all formed from the same gas cloud. You can also see what the Pleiades might have like in a primordial state, by shifting your gaze to the prominent constellation Orion the Hunter. Look for Orion’s sword stars, just below his prominent belt stars. If the night is crisp and clear, and you’re away from urban streetlight glare, unaided eyes will show that the sword isn’t entirely composed of stars. Binoculars show a steady patch of glowing gas where, right at this moment, a star cluster is being born. It’s called the Orion Nebula. A summertime counterpart is the Lagoon Nebula, in Sagittarius the Archer.
With star factories like the Orion Nebula, we aren’t really seeing the young stars themselves. They are buried deep within the nebula, bathing the gas cloud with ultraviolet radiation and making it glow. In a few tens of thousands of years, stellar winds from these young, energetic stars will blow away their gaseous cocoons to reveal a newly minted star cluster.
Scan along the Milky Way to see still more sights that hint at our home galaxy’s complexity. First, there’s the Milky Way glow itself; just a casual glance through binoculars will reveal that it is still more stars we can’t resolve with our eyes . . . hundreds of thousands of them. Periodically, while scanning, you might sweep past what appears to be blob-like, black voids in the stellar sheen. These are dark, non-glowing pockets of gas and dust that we see silhouetted against the stellar backdrop. This is the stuff of future star and solar systems, just waiting around to coalesce into new suns.
Andromeda Galaxy from Chris Levitan Photography.
Many people use the M- or W-shaped constellation Cassiopeia to find the Andromeda Galaxy. See how the star Schedar points to the galaxy?
It’s a whole other galaxy like our own, shining across the vastness of intergalactic space. Light from the Andromeda Galaxy has traveled so far that it’s taken more than 2 million years to reach us.
Two smaller companions visible through binoculars on a dark, transparent night are the Andromeda Galaxy’s version of our Milky Way’s Magellanic Clouds. These small, orbiting, irregularly-shaped galaxies that will eventually be torn apart by their parent galaxy’s gravity.
Such sights, from lunar wastelands to the glow of a nearby island universe, are all within reach of a pair of handheld optics, really small telescopes in their own right: your binoculars.
John Shibley wrote the original draft of this article, years ago, and we’ve been expanding it and updating it ever since. Thanks, John!
Bottom line: For beginning stargazers, there’s no better tool than an ordinary pair of binoculars. This post tells you why, explains what size to get, and gives you a rundown on some of the coolest binoculars sights out there: the moon, the planets, inside the Milky Way, and beyond. Have fun!
Divers inspect a hole being dug beside a wooden beam jutting from the floor of Lake Michigan during a search for the Griffin. (AP Photo/Great Lakes Exploration Group, David J. Ruck ) ...
Excerpt from
independent.co.uk
It is one of the world’s last frontiers and has seen fewer human visitors than the moon. And that – for the time being at least – is how it shall stay.
Sir Richard Branson has shelved plans for a submarine to take tourists to the bottom of Pacific’s Mariana Trench, after technical problems hobbled the grand ambitions of his much-trumpeted Virgin Oceanic project.The news is a second blow to Branson’s adventurer dreams in a matter of months, after a Virgin Galactic space rocket crashed on a test flight in California’s Mojave Desert, killing a pilot.
Virgin Oceanic’s DeepFlight Challenger was launched in 2011 with the entrepreneur’s familiar fanfare. Under the plans, wealthy passengers or “aquanauts” up would pay up to $500,000 (£318,126) for a five-dive package labelled as “the last great challenge for humans”.
As well as exploring the Mariana Trench – a 36,000ft-deep abyss is deeper than Mount Everest is tall, with access so risky and complicated that it has had just three human visitors since its formation nine million years ago – the submarine was due to dive the Puerto Rico trench 28,000ft below the surface of the Atlantic, the Molloy Deep in the Arctic, South Sandwich Trench in the Southern Ocean and Diamantina trench in the Indian Ocean.
But yesterday the Sunday Telegraph reported that Deepflight, the company contracted to build the submarine, could not support the project because their vehicle could only be safely used for one dive.
The underwater mission appears to have stalled indefinitely. The Virgin Oceanic website – which had promised “five dives, five oceans, two years, one epic adventure” – no longer exists, reportedly taken down earlier this year.
Excerpt from abcnews.go.comEveryone moans about the high price of airline tickets and sometimes they're very high. Like now, when non-stops between New York and Los Angeles in July are running about $600+, whereas May flights could be had for less t...
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| Scene from a NASA animation showing two neutron stars colliding. |
Excerpt from
space.com
By looking for ripples in the fabric of space-time, scientists could soon detect "strange stars" — objects made of stuff radically different from the particles that make up ordinary matter, researchers say.
The protons and neutrons that make up the nuclei of atoms are made of more basic particles known as quarks. There are six types, or "flavors," of quarks: up, down, top, bottom, charm and strange. Each proton or neutron is made of three quarks: Each proton is composed of two up quarks and one down quark, and each neutron is made of two down quarks and one up quark.
In theory, matter can be made with other flavors of quarks as well. Since the 1970s, scientists have suggested that particles of "strange matter" known as strangelets — made of equal numbers of up, down and strange quarks — could exist. In principle, strange matter should be heavier and more stable than normal matter, and might even be capable of converting ordinary matter it comes in contact with into strange matter. However, lab experiments have not yet created any strange matter, so its existence remains uncertain.
One place strange matter could naturally be created is inside neutron stars, the remnants of stars that died in catastrophic explosions known as supernovas. Neutron stars are typically small, with diameters of about 12 miles (19 kilometers) or so, but are so dense that they weigh as much as the sun. A chunk of a neutron star the size of a sugar cube can weigh as much as 100 million tons.
Under the extraordinary force of this extreme weight, some of the up and down quarks that make up neutron stars could get converted into strange quarks, leading to strange stars made of strange matter, researchers say.
A strange star that occasionally spurts out strange matter could quickly convert a neutron star orbiting it in a binary system into a strange star as well. Prior research suggests that a neutron star that receives a seed of strange matter from a companion strange star could transition to a strange star in just 1 millisecond to 1 second.
Now, researchers suggest they could detect strange stars by looking for the stars' gravitational waves — invisible ripples in space-time first proposed by Albert Einstein as part of his theory of general relativity.
Gravitational waves are emitted by accelerating masses. Really big gravitational waves are emitted by really big masses, such as pairs of neutron stars merging with one another.
Pairs of strange stars should give off gravitational waves that are different from those emitted by pairs of "normal" neutron stars because strange stars should be more compact, researchers said. For instance, a neutron star with a mass one-fifth that of the sun should be more than 18 miles (30 km) in diameter, whereas a strange star of the same mass should be a maximum of 6 miles (10 km) wide.
The researchers suggest that events involving strange stars could explain two short gamma-ray bursts — giant explosions lasting less than 2 seconds — seen in deep space in 2005 and 2007. The Laser Interferometer Gravitational-Wave Observatory (LIGO) did not detect gravitational waves from either of these events, dubbed GRB 051103 and GRB 070201.
Neutron star mergers are the leading explanations for short gamma-ray bursts, but LIGO should, in principle, have detected gravitational waves from such mergers. However, if strange stars were involved in both of these events, LIGO would not have been able to detect any gravitational waves they emitted, researchers said. (The more compact a star is within a binary system of two stars, the higher the frequency of the gravitational waves it gives off.)
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Excerpt from livescience.com
When a pair of fishermen waded into the frigid waters of the southern Baltic Sea about 5,000 years ago, they probably didn't realize that the shifting seabed beneath their feet was recording their every move. But it was.
The long-lost evidence of that prehistoric fishing trip — two sets of human footprints and some Stone Age fishing gear — was recently discovered in a dried up fjord, or inlet, on the island of Lolland in Denmark. There, archaeologists uncovered the prints alongside a so-called fishing fence, a tool that dates back to around 3,000 B.C.
Archaeologists have found fishing fences before, but the footprints are the first of their kind discovered in Denmark, according to Terje Stafseth, an archaeologist with the Museum Lolland-Falster, who helped excavate the ancient prints.
"This is really quite extraordinary, finding footprints from humans," Stafseth said in a statement. "Normally, what we find is their rubbish in the form of tools and pottery, but here, we suddenly have a completely different type of trace from the past, footprints left by a human being."
The Stone Age footprints were likely formed sometime between 5,000 B.C. and 2,000 B.C., Jensen said. At that time, the water level of the Baltic Sea was rising due to melting glaciers in northern Europe. Also at that time, prehistoric people were using these inlets as fishing grounds.
These individuals constructed elaborate traps, called fishing fences, to catch their prey. The wooden fences were built in sections several feet wide — thin switches of hazel suspended between two larger sticks — and the sections were lined up consecutively to form one long, continuous trap. The trap was placed in the shallow water of the fjord, which would be flooded with the incoming tide, the archaeologists said. When the fishermen wanted to move their gear, they would pluck the sections of the fence from the claylike floor of the fjord and move the whole apparatus to a new location.
"What seems to have happened was that at some point they were moving out to the [fish fence], perhaps to recover it before a storm," Jensen said. "At one of the posts, there are footprints on each side of the post, where someone had been trying to remove it from the sea bottom."
The archaeologists said the footprints must have been made by two different people, since one set of prints is significantly smaller than the other. Jensen and his team are now making imprints, or flat molds, of the footprints to preserve these ancient signs of life.
In addition to the human tracks, the team uncovered several skulls belonging to domestic and wild animals on the beach near the fjord.
The researchers said the skulls were likely part of offerings made by local farmers, who inhabited the region from around 4,000 B.C.
"They put fragments of skulls from different kinds of animals [on the sea floor], and then around that they put craniums from cows and sheep," Jensen said. "At the outermost of this area, they put shafts from axes. All in all, it covers about 70 square meters [83 square yards]. It's rather peculiar."
Vladimir Pushkarev/Russian Centre of Arctic ExplorationExcerpt from nbcnews.com The mystery of the Siberian craters is one step closer to being solved. Earlier this week, Russian scientists descended into one of the massive craters that was dis...
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Elon Musk fears our progress in artificial intelligence is ‘seriously dangerous’
Excerpt from
sciencerecorder.com
Visionary technology figure Elon Musk has been warning the public for months about possible threats posed by artificial intelligence. But now he has a timeline.
Musk, the South African-born CEO of Tesla Motors and SpaceX, wrote that “the risk of something seriously dangerous happening is in the five year time frame. 10 years at most.”
Musk penned this comment at the bottom of an essay written by virtual pioneer Jaron Lanier called “The Myth of A.I.” The essay appeared in the publication Edge.org last week and was followed by comments from such technology notables as George Dyson, Peter Diamandis, and Kevin Kelly.
While Musk’s comment was deleted, it was picked up by sites such as Mashable and Reddit, which preserved it for a larger audience. According to these sites, Musk zeroed in on companies such as DeepMind, a British artificial intelligence company that Musk once invested in before it was purchased by Google.
“The pace of progress in artificial intelligence (I’m not referring to narrow AI) is incredibly fast,” Musk’s piece read. “Unless you have direct exposure to groups like DeepMind, you have no idea how fast-it is growing at a pace close to exponential.”
Musk mentioned that AI companies “recognize the danger” and were working to ameliorate any negative intelligences “from escaping into the Internet.”
While Musk had sent his comment privately to Edge.org by email, it was published by a site editor before it was taken down. A Musk spokesperson has said that Musk will write a longer piece outlining his thoughts on the dangers of artificial intelligence, presumably to be published on the same website.
Previously, Musk has compared AI to “summoning the demon,” nuclear war, and the “Terminator” series.