Space News/UFO's Etc...(Discussion/Pics/Vids)
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Black holes hide in our cosmic backyard
Elizabeth Landau, PHYS.ORG | January 8, 2017
Elizabeth Landau, PHYS.ORG | January 8, 2017
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"These black holes are relatively close to the Milky Way, but they have remained hidden from us until now," said Ady Annuar, a graduate student at Durham University in the United Kingdom, who presented the results at the American Astronomical Society meeting in Grapevine, Texas. "They're like monsters hiding under your bed."
Both of these black holes are the central engines of what astronomers call "active galactic nuclei," a class of extremely bright objects that includes quasars and blazars. Depending on how these galactic nuclei are oriented and what sort of material surrounds them, they appear very different when examined with telescopes.
Active galactic nuclei are so bright because particles in the regions around the black hole get very hot and emit radiation across the full electromagnetic spectrum—from low-energy radio waves to high-energy X-rays. However, most active nuclei are believed to be surrounded by a doughnut-shaped region of thick gas and dust that obscures the central regions from certain lines of sight. Both of the active galactic nuclei that NuSTAR recently studied appear to be oriented such that astronomers view them edge-on. That means that instead of seeing the bright central regions, our telescopes primarily see the reflected X-rays from the doughnut-shaped obscuring material.
"Just as we can't see the sun on a cloudy day, we can't directly see how bright these active galactic nuclei really are because of all of the gas and dust surrounding the central engine," said Peter Boorman, a graduate student at the University of Southampton in the United Kingdom.
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More surprising is the spiral galaxy that Annuar focused on: NGC 1448. The black hole in its center was only discovered in 2009, even though it is at the center of one of the nearest large galaxies to our Milky Way. By "near," astronomers mean NGC 1448 is only 38 million light years away (one light year is about 6 trillion miles).
Annuar's study discovered that this galaxy also has a thick column of gas hiding the central black hole, which could be part of a doughnut-shaped region. X-ray emission from NGC 1448, as seen by NuSTAR and Chandra, suggests for the first time that, as with IC 3639, there must be a thick layer of gas and dust hiding the active black hole in this galaxy from our line of sight.
Researchers also found that NGC 1448 has a large population of young (just 5 million year old) stars, suggesting that the galaxy produces new stars at the same time that its black hole feeds on gas and dust. Researchers used the European Southern Observatory New Technology Telescope to image NGC 1448 at optical wavelengths, and identified where exactly in the galaxy the black hole should be. A black hole's location can be hard to pinpoint because the centers of galaxies are crowded with stars. Large optical and radio telescopes can help detect light from around black holes so that astronomers can find their location and piece together the story of their growth.
"It is exciting to use the power of NuSTAR to get important, unique information on these beasts, even in our cosmic backyard where they can be studied in detail," said Daniel Stern, NuSTAR project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California.
This study shows Earth may have harbored complex life 2 billion years ago
Nicole Kiefert, Astronomy Magazine | January 18, 2017
And how selenium could expand the search of extraterrestrial life
Everyone is still looking for evidence of life on another planet, and there’s no better way to start a search than to look at what’s already been successful and why.Nicole Kiefert, Astronomy Magazine | January 18, 2017
And how selenium could expand the search of extraterrestrial life
This photo taken by a coauthor of the study shows the Gunflint Formation, a 1.9 billion-year-old mound of microbes in shallow water, in Minnesota. Eva Stüeken |
That’s why a team at the University of Washington did a study of Earth’s oceans and ended up finding that they held suitable conditions for life at one point in time. This point occurred more than a billion years before the first fossils appeared.
Michael Kipp, a UW doctoral student in Earth and Space Sciences and lead author of the paper, studied sedimentary rocks to derive the amount of oxygen in Earth’s atmosphere between 2 and 2.4 billion years ago. During this study, he analyzed isotopic ratios of selenium in the sedimentary rocks to measure the oxygen amounts.
Professor Roger Buick, coauthor of the study and faculty member of the UW Astrobiology Program, said in a press release that the evidence they found dates very far back.
“There is fossil evidence of complex cells that go back maybe 1.75 billion years,” Buick said. “But the oldest fossil is not necessarily the oldest one that ever lived because the chances of getting preserved as a fossil are pretty low.”
He added that though this fossil was evidence of enough oxygen to allow complex cells to evolve and “become ecologically important,” that doesn’t necessarily mean that they did.
The team analyzed selenium in sedimentary shale to see if the element had been affected by oxygen, or oxidized. If selenium was oxidized, it could cause a shift in the rocks’ isotopic ratios. The presence of oxygen should also increase the amount of selenium in the rocks.
It has always been assumed that the oxygen levels on Earth steadily increased from a little to the amount we have now, but Buick said this research may prove otherwise.
“What it looks like now is, there was a period of a quarter of a billion years or so where oxygen came quite high, and then sunk back down again,” Buick said.
It’s still unknown why the oxygen levels rose and fell, but using selenium to look for oxygen could be a helpful tool in the search for life beyond Earth.
“This is a new way of measuring oxygen in a planet’s historical past, to see whether complex life could have evolved there and persisted long enough to evolve into intelligent beings,” Buick said.
The CIA just declassified millions of pages.
You can search using "keywords" ie...UFO's, mind control etc... at this site.
Lots of interesting reading this weekend...
Enjoy!!!
You can search using "keywords" ie...UFO's, mind control etc... at this site.
HTML:
https://www.cia.gov/library/readingroom/search/site/UFOLots of interesting reading this weekend...
Enjoy!!!
It mimics the movies. Without knowing what "the craft" is all about, they're trying to shoot it down.
I was thinking the same thing.
Why would they open fire on it ?
I got thinking about drones... I suppose shooting at it could be atrributed to all the drones in the skys these days and we all now know what these drones are capable of. at the hands of the governements.
These guys may not have thought UFO, but instead were thinking drone
ALMA starts observing the Sun
Stephen Clark, Astronomy Now | 17 January 2017
Stephen Clark, Astronomy Now | 17 January 2017
This ALMA image of an enormous sunspot was taken at a wavelength of 1.25 millimetres. Sunspots are transient features that occur in regions where the Sun’s magnetic field is extremely concentrated and powerful. They have lower temperatures than their surrounding regions, which is why they appear relatively dark. Credit: ALMA (ESO/NAOJ/NRAO) |
The results are an important expansion of the range of observations that can be used to probe the physics of our nearest star. The ALMA antennas had been carefully designed so they could image the Sun without being damaged by the intense heat of the focussed light.
Astronomers have harnessed ALMA’s capabilities to image the millimetre-wavelength light emitted by the Sun’s chromosphere — the region that lies just above the photosphere, which forms the visible surface of the Sun. The solar campaign team, an international group of astronomers with members from Europe, North America and East Asia, produced the images as a demonstration of ALMA’s ability to study solar activity at longer wavelengths of light than are typically available to solar observatories on Earth.
Astronomers have studied the Sun and probed its dynamic surface and energetic atmosphere in many ways through the centuries. But, to achieve a fuller understanding, astronomers need to study it across the entire electromagnetic spectrum, including the millimetre and submillimetre portion that ALMA can observe.
A map of the whole disc of the Sun was also made with a single ALMA antenna, using a technique called fast-scanning, at a wavelength of 1.25 millimetres. The accuracy and speed of observing with a single ALMA antenna make it possible to produce a map of the entire solar disc in just a few minutes. These maps show the distribution of temperatures in the chromosphere over the whole disc at low spatial resolution and therefore complement the detailed interferometric images of individual regions of interest. Credit: ALMA (ESO/NAOJ/NRAO) |
The team observed an enormous sunspot at wavelengths of 1.25 millimetres and 3 millimetres using two of ALMA’s receiver bands. The images reveal differences in temperature between parts of the Sun’s chromosphere. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed in the future using ALMA.
Sunspots are transient features that occur in regions where the Sun’s magnetic field is extremely concentrated and powerful. They are lower in temperature than the surrounding regions, which is why they appear relatively dark.
The difference in appearance between the two images is due to the different wavelengths of emitted light being observed. Observations at shorter wavelengths are able to probe deeper into the Sun, meaning the 1.25 millimetre images show a layer of the chromosphere that is deeper, and therefore closer to the photosphere, than those made at a wavelength of 3 millimetres.
ALMA is the first facility where ESO is a partner that allows astronomers to study the nearest star, our own Sun. All other existing and past ESO facilities need to be protected from the intense solar radiation to avoid damage. The new ALMA capabilities will expand the ESO community to include solar astronomers.
Fallout from an ancient asteroid collision still rains on Earth
Nathaniel Scharping, Astronomy Magazine | Tuesday, January 24, 2017
Extraterrestrial objects are constantly bombarding Earth; thankfully the vast majority are microscopic.
Nathaniel Scharping, Astronomy Magazine | Tuesday, January 24, 2017
Extraterrestrial objects are constantly bombarding Earth; thankfully the vast majority are microscopic.
Thanks to the planet’s atmosphere, we live largely unaware of this celestial fusillade, which averages about 100 tons a day and mostly burns up long before hitting the ground. From the few that do make impact, researchers can gather clues about the composition of our solar system, with the goal of understanding how planets and other bodies emerged from an embryonic disk of dust and gas some 5 billion years ago.
However, it seems many of the samples researchers have to work with originated from a single event that’s been raining fallout for some 466 million years, giving us a biased picture of what’s actually out there.
Brief Moment in Time
At the moment, we seem to experiencing a fairly heavy rain of rocky meteorites called ordinary chondrites, which are distinguished by the presence of drop-like structures embedded in their bodies. Chondrites are further divided into three classes: H, L and LL, each thought to correspond to a different impact event long ago. We’re currently seeing a disproportionate number of H and L-type chondrites hit the Earth, but, it wasn’t always so.
Researchers from the Field Museum of Natural History, the University of Chicago and Lund University in Sweden recently conducted an analysis of sediment samples from the Ordovician period, some 466 million years ago, to give us a glimpse of what was hitting the Earth at a very different point in its history. They collected their samples from a site near St. Petersburg in Russia, where the layers of rock are known to have built up very slowly, thus making it much more likely that a meteorite will be found in any given strata. A similar site in Sweden was responsible for the “extinct” Österplana 065 meteorite discovered in 2016.
[We’re] doing space exploration with geological methods, essentially,” says Philipp Heck, the curator of meteorites for the Field Museum and lead author of the paper.
The researchers then dissolved 600 pounds of rock in acid and sieved through the remains in the hopes of sifting out tiny grains of chromite, called spinels, delivered to Earth by meteorites. Analyzing the isotopic composition of these spinels allows researchers to classify the kind of meteorites they came from and take a kind of census of impacts at different points in the Earth’s history. They published their work Monday in Nature Astronomy.
Turning Point
The time period the researchers were interested in occurred just before a major impact event somewhere in our solar system that delivered a hail of L-chondrite meteors to Earth beginning 466 million years ago. The bombardment was so heavy that it obscured nearly all other impacts in the geologic record for a million years, and we’re still feeling the fallout today.
Looking at a slice of time around a million years before the event, the researchers took a census of the meteorites that intersected the Earth’s orbit, and found that the cosmic rain looked very different back then.
Instead of the L- and H-chondrites that we see today, a different kind of meteorite, called achondrites, made up nearly half of the micrometeorite impacts in the Ordovician. Anywhere from 10 to 29 percent of these were a type of achondrite that likely resulted from a massive collision on Vesta, the second-largest asteroid in the solar system at over 300 miles in diameter.
Achondrites are meteorites that appear to have been melted and reformed at some point in their lives, such as on Vesta, where molten lava flows likely reshaped the surface at some point early in its life. Today, achondrites are considered rare, say the researchers.
In addition, there were many more LL-chondrites and fewer H-chondrites during the Ordovician. While the origins of these meteorites remain unclear, they likely result from periodic collisions among asteroids and other objects in the solar system, as well as gravitational perturbations from planets that alter the path of the millions of asteroids and other objects floating around the solar system.
By just studying meteorites, we’re likely to never get a balanced view of the solar system, however, says Heck. Not only did they find that our current barrage of meteorites was biased, but their results indicate that some kind of bias is always present.
“The composition of meteorites doesn’t match the composition of asteroids,” he says. “[It] depends on what collision happened, we get different fragments from other sources.”
In other words, the heavenly rock showers that bathe the Earth give us only a snapshot of what the solar system looks like right now. For the full picture, we need to look elsewhere.
Star birth with a chance of winds?
Karl Hille, Phys.Org | 27 january 2017
The lesser-known constellation of Canes Venatici (The Hunting Dogs), is home to a variety of deep-sky objects—including this beautiful galaxy, known as NGC 4861. Astronomers are still debating on how to classify it. While its physical properties—such as mass, size and rotational velocity—indicate it to be a spiral galaxy, its appearance looks more like a comet with its dense, luminous "head" and dimmer "tail" trailing off. Features more fitting with a dwarf irregular galaxy.Karl Hille, Phys.Org | 27 january 2017
The lesser-known constellation of Canes Venatici (The Hunting Dogs), is home to a variety of deep-sky objects -- including this beautiful galaxy, known as NGC 4861. Astronomers are still debating on how to classify it. While its physical properties -- such as mass, size and rotational velocity -- indicate it to be a spiral galaxy, its appearance looks more like a comet with its dense, luminous 'head' and dimmer 'tail' trailing off. Features more fitting with a dwarf irregular galaxy. Credit: ESA/Hubble & NASA |
Although small and messy, galaxies like NGC 4861 provide astronomers with interesting opportunities for study. Small galaxies have lower gravitational potentials, which simply means that it takes less energy to move stuff about inside them than it does in other galaxies. As a result, moving in, around, and through such a tiny galaxy is quite easy to do, making them far more likely to be filled with streams and outflows of speedy charged particles known as galactic winds, which can flood such galaxies with little effort.
These galactic winds can be powered by the ongoing process of star formation, which involves huge amounts of energy. New stars are springing into life within the bright, colorful 'head' of NGC 4861 and ejecting streams of high-speed particles as they do so, which flood outwards to join the wider galactic wind. While NGC 4861 would be a perfect candidate to study such winds, recent studies did not find any galactic winds in it.
